On Osprey Time 2014
#57
Wired Up and Winging Down the Flyway
November 10, 2014
Miniaturized solar-powered GPS (global positioning system) trackers and newer solar-powered GSM (groupe spécial mobile) transmitters allow researchers to track movements of tagged osprey and other avian species. In North America, Rob Bierregaard <http://www.ospreytrax.com> and others in the tracking community are following the daily movements of ospreys outfitted with a one-ounce device fitted with a ten-inch antenna.
Silhouette of osprey flying with one-ounce GMS backpack with 10 inch antenna protruding up. (Courtesy of Lanny McDowell and OspreyTrax).
The nest life of established osprey pairs is well studied. However, before the development of the GPS/GMS technology, there was no way to track the daily habits of juveniles, migrating and wintering adults, and the younger, non-breeding adults often called intruders when they investigate existing nests. Recent studies are shedding light on osprey fishing strategies, juvenile explorations, and seasonal migrations, all highlighting previously unknown idiosyncrasies. GPS data reveals the behavioral variation among individuals, highlights the explorations of younger birds, and demonstrates the evolution of an individual's migration routes over time.
Rob Bierregaard's tagged ospreys and discovered some striking variations between individuals, the sexes, and age classes. Belle, a single female osprey, was trapped as a fledgling on Martha's Vineyard, MA, in July 2010 and has completed three fall and spring migrations. She winters in a 6-square mile area on the Rio Madeira at Brazil’s southern edge of the Amazon rainforest. Belle is found at Deep Bottom on Martha's Vineyard as well as at several ponds on Cape Cod.
Belle flying with her backpack. The antenna is visible extending from her back.
(Courtesy of Mark Alan Lovewell and OspreyTrax.)
Belle's first migration in 2010 took her out over the Atlantic, 200 miles shy of Bermuda when she was 4 months old. Ospreys cannot float like gulls and can drown if they become exhausted over open water. On her first return flight north in 2012, she stopped in at Haiti and took a more direct inland route.
With each migration Belle decreased the amount of risky time spent travelling overwater. Eventually she followed the coast to the Florida Keys, where all the adult ospreys know to go to get to South America while staying over land as much as possible. Each trip north and south she led her closer to her "adult" path. By her fourth trip to South America, she mastered the preferred "adult" route, maximizing the time spent travelling overland while minimizing stretches over open water.
Map showing the evolution of Belle's migration route until it followed the more "adult" pathway overland. (Courtesy of OspreyTrax.)
Belle, now 4-years old and still unmated, is a perpetual latecomer, arriving at the Vineyard breeding grounds after all the choice mates and nest sites are taken. However, each year Belle leaves Rio Madeira a bit earlier, possibly learning she needs to step up her game if she wants a mate.
Ospreys tend to wander on their migratory journeys, not sticking to exact routes as long as they're staying over land and heading in the right general direction. When close to their final destination, their navigational skills kick into gear, and they head directly for their nest or favorite winter roost.
Each year as Belle arrives in Haiti, she makes a detour east of Port-au-Prince to Lake Azuei, largest lake in Haiti (see green data points for March 28 and 29). (Courtesy of OspreyTrax.)
Belle's southern trek this year took her directly across the Caribbean. She left the Dominican Republic at Cabo Beata in the early morning and, winging it 420-miles non-stop, made landfall in Columbia at 2:30 am the next morning. She left before 9 am and was looking for a place to roost SW of Maracaibo, Venezuela by that evening. The next morning she crossed Lake Maracaibo, found a pass through the Cordillera Oriental, flew across the Venezuelan llanos, and entered the northern limits of the South American rainforests on the 14th of xx.
On her first return trip north in spring 2012, Belle knew the direction she had to take to get back to the Rio Madeira and has maintained that route in subsequent migrations across the Amazonian rainforest. With each successive migration her well-worn paths more precisely match: she's developing routines. She now leaves from the same spot on the Guajira Peninsula west of the Gulf of Venezuela. As of October 20, she was only 190 miles from her winter home on the Rio Madeira. In total, her remarkable 4,385-mile trip began on September 19, 2014 and ended 34 days later at her winter home on the banks of the Rio Madeira.
In addition to studying migration, GMS-tagged juveniles and unmated young adults are revealing many surprises. Of three juveniles living in the Connecticut River Estuary, two feast on the abundant menhaden congregating at the mouth of the Connecticut River. The third juvenile partakes of this menhaden feast as well, but spends more time flying miles inland to fish in a river.
Clyde, a juvenile tagged on Long Island's North Fork, made it to South America in 9 days, an impressive flight for a young osprey! He seems to be staying at the mouth of Lake Maracaibo in western Venezuela, but it is premature to say if he'll settle here for the next 18 months. After first arriving in South America, juveniles typically explore for a few months before settling down.
Long Island's own North Fork Bob. (Courtesy of OspreyTrax.)
This summer was North Fork Bob's fourth year wearing the tracking gear. He's a non-breeding osprey also from North Fork and seems to lead an easy life. Despite a quick trip to Rhode Island and some exploring in Connecticut after he got home, Bob spent the summer on Long Island around the North and South Forks and Deep Cove Creek. Unlike the past few summers, he showed no interest in the nearby marsh nest pole, spending many afternoon hours standing in the open fields north of Deep Cove. One or two ospreys join him. Why is anyone's guess.
North Fork Bob's movements when he first arrived home in Long Island in April 2014.
(Courtesy of OspreyTrax.)
Osprey nest watchers have known that ospreys are very individualistic birds with strong personalities. Trackers confirm that every osprey has its own story, often revealing unusual, bizarre, and seemingly quirky behaviors. Insights into their daily lives, roaming and explorations, and seasonal migrations are arriving constantly. Check out the tracking programs listed below to learn more about this exciting new window into the world of ospreys.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
To Follow Ospreys Migrating from North America Tracking Sites
• Project OspreyTrak, Center for Conservation Biology, VA <www.ccbbirds.org/what-we-do/research/species-of-concern/species-of-concern-projects/ospreytrak-project>
• OspreyTrax, Rob Bierregaard <www.ospreytrax.com>
• Project OspreyTrack. Squam Lakes Nature Center, NH <www.nhnature.org/programs/project_ospreytrack/osprey_maps.php>
• Jamaica Bay Wildlife Refuge, NY <www.jamaicabayosprey.org>
• Friends of the Osprey & Bird Studies Canada, Canada <www.friendsoftheosprey.org/telemetry. html>
#56
Osprey Spectacle in the Connecticut River Estuary
October 2, 2014
The Connecticut River Estuary entering Long Island Sound (courtesy of RiverQuest).
Spectacles of nature, like the Osprey-Bunker Banquet in southeastern Connecticut last weekend, take your breath away. The thrill of experiencing such massive concentrations of powerful birds captures the imagination, leaving an indelible sense of awe in the beholder. Since late August, a vast school of northbound Atlantic Menhaden (Brevoortia tyrannus or "bunkers") have been corralled in the Connecticut River Estuary (CRE) between Old Lyme and Old Saybrook by bluefish and other predators. Migrating juvenile ospreys congregate here by the dozens, exploiting the extra fishing practice and gorging themselves on easy prey. I came here to witness this unusual feast, but quickly realized its true significance—the fact that an osprey-menhaden banquet story still exists is a miracle given their precipitous population declines in the last sixty years. The sight of these two recovering populations together gives real hope.
A sky full of juvenile ospreys at South Cove (courtesy of Kristofer Rowe).
When first approaching South Cove from Rt. 154,the air rings with the cries of ospreys, and the sky seems full of hunting juveniles, wheeling overhead and swooping down to fish. At any one time, 20-40 ospreys circle above the cove, and, by afternoon the tree line gradually fills with dining ospreys. Later, as bluefish drive more menhaden into the cramped cove, the water boils with splashing, panicking fish, some of which are scarred by bluefish tears.
(Courtesy of Kristofer Rowe.)
(Courtesy of Kristofer Rowe.)
(Courtesy of Kristofer Rowe.)
(Courtesy of Kristofer Rowe.)
(Courtesy of Kristofer Rowe.)
(Courtesy of Kristofer Rowe.)
Most osprey colonies along the Connecticut River and elsewhere in the Northeast emptied in late August to mid-September as adults and juveniles migrate. However, the juveniles stopping over at CRE seem to be in no hurry to leave this bounty. Unlike the elegant high-dives of their parents, juveniles first make shorter transitional dives, gaining height and accuracy with practice. These extra practice sessions are invaluable to the juveniles and may enhance their chances of survival.
(Courtesy of Kristofer Rowe.)
These vast marshes remind me of the colorful heritage of this estuary and how we nearly lost it to DDT, an anti-mosquito agent, during the Golden Age of Pesticides (1950-60s). Roger Tory Peterson, originator of the modern field guide, lived next to the CRE in Old Lyme from 1954-96 and watched as DDT worked its way up aquatic food chain and the thriving 200-nest osprey colony collapsed. Peterson and friends, including writer and marine biologist Rachael Carson, sparked public outcry for a solution as osprey, peregrines, and bald eagles raced toward eradication across the US. Carson'sSilent Spring, damning DDT, became one of the most influential books of the 20th century, leading to the formation of the Environmental Protection Agency and the 1972 ban on DDT and other persistent pesticides.
For more than 65 years, Peterson Field Guides have set the standard by which other field guides are measured. Comprehensive and authoritative, they are essential additions to any naturalist's bookshelf or backpack. Roger Tory Peterson, one of the world's greatest naturalists, spent his life studying, painting, and photographing birds. The Peterson Identification System has been called the greatest invention since binoculars, and the Peterson Field Guide Series is credited with helping to set the stage for the environmental movement. Peterson died in 1996.
Osprey nesting platform on Great Island across from Smith's Neck Road Landing, off Route 156.
Thanks to ample food, enduring research and successful egg hacking programs, and tireless stewards building and maintaining nesting platforms, our raptor populations have largely recovered. Peterson and his friends began the tradition of citizen-led environmental action by building nest platforms in the CRE, a movement sustained today by the strength of his ecological vision. Nesting on all 100 CRE platforms, the ospreys are thriving. In 2014, a dozen pairs tried but failed to nest without platforms in the marshes as the colony slowly repatriates upstream. Two pairs also nested successfully the "old-fashioned way" in trees.
(Courtesy of Kristofer Rowe.)
Today's osprey-bunker banquet is testament to ospreys' resiliency, yet that's only half the story unfolding at the causeway. Today's menhadens are also imperiled from a half-century of systematic overharvesting using WWII spotter planes and industrial seines. The once endless supply of plankton-eating menhadens, the essential foundation on which the marine food chain depends, is now at risk. Although essentially herbivorous, menhadens do eat some zooplankton. However, menhadens are essential to the oceans as the primary source of energy conversion from plants and detritus into animal protein.
Menhadens and their filter-feeding relatives—sardines, shads, and herrings—are also the all-important "vacuum cleaners of the sea.” These migrants, originating around the Chesapeake Bay and mid-Atlantic region, are attracted to the CRE and other northern estuaries where plankton thrive on excess nitrogen and phosphorus brought down the rivers in storm-water runoff.
"Standards" or three year-old menhaden swimming with their mouths open to filter feed (courtesy of Kristofer Rowe).
As menhaden migrate along the coast, they clarify the bays and estuaries by removing suspended particles from the water. Immense schools of bunkers up to 40 miles long swim with their large mouths open, each filtering up to seven gallons of seawater per minute and one million gallons every 180 days. Clear water lets sunlight penetrate to greater depths, encouraging photosynthesis and the release of dissolved oxygen. Without these filter feeders, the oceans would suffer nutrient overload and die. It's akin to an animal losing its kidneys. By doing so, they maintain balanced marine ecosystems.
(Courtesy of Kristofer Rowe.)
Decades of overharvesting are now threatening menhaden survival and that of the entire marine ecosystem. But since we don't eat them, most people have never heard of a menhaden. The CRE and other northern coastal waters no longer permit commercial fishing, offering sanctuary to these crucial species. But most menhaden must begin life in the dangerous waters around the Mid-Atlantic and Chesapeake Bay. The eggs hatch in the open ocean and the larvae drift along currents into sheltered Mid-Atlantic estuaries and the Chesapeake Bay. The young spend a year developing in these waters before migrating in the open ocean as small "peanut bunkers." On Maryland's side of the Chesapeake, these fish are highly protected and considered the “breadbasket of the ocean." In Virginia's waters, however, factory ships use vacuum tubes to suck whole schools of menhaden--millions of them--into their holds to process for chicken feed. More are caught seining coastal waters (within three miles of shore) from Virginia to New Jersey.
"Peanut" bunkers (courtesy of Kristofer Rowe).
Migrating menhaden sort themselves by size before migrating. The bunkers in this summer's banquet spanning the entire estuary are uniformly three years old and weigh up to a pound. These fat oily menhaden swimming in massive schools of closely ranked individuals are helpless with few protections other than their coloration and sheer numbers. It is no wonder it falls prey to every predaceous animal around, especially bluefish, striped bass, weakfish, haddock, halibut, mackerel, swordfish, tuna, sharks, and rays. Their schooling behavior also attracts ospreys, loons, herons, egrets, gulls, gannets, eagles, and marine mammals such as whales and dolphins. Peterson referred to the common sight of an osprey carrying a shiny, blunt-headed, fork-tailed menhaden as “all field mark." An osprey with a fresh catch kindly demonstrated by parading the bunker before the line of scopes and cameras on the causeway.
Roger Tory Peterson called an osprey towing a menhaden “all field mark" (Courtesy of Kristofer Rowe.)
I also realized what a profound event and set of circumstances this really was—an elite fishing camp training young ospreys and the reunion of two intertwined species almost driven to extinction. Recently, menhadens numbers are rising and schools are returning to Connecticut’s bays and estuaries. The press claims a population upswing, but that is premature. Some recovery is indicated by an increase in predatory game fish driving the menhaden.
Paul Spitzer and others are helping to rebuilding the historic osprey colony on Great Island.
"There have been smaller osprey-bunker gatherings at South Cove, but not nearly so abundant as this year," says conservation biologist and CRE native son, Dr. Paul Spitzer (a Cornell PhD). "This probably reflects the 2013 menhaden harvest cap, which helped bring their population numbers up. This great natural drama of menhaden recovery is playing out before our eyes." And the osprey watching doesn't get better than this.
(Courtesy of Kristofer Rowe.)
Spitzer and others are helping to rebuild the osprey colony and will use it partly as a biomonitor of menhaden numbers to ensure the fisheries' compliance with regulations. Only time will tell if this industrious fish can recover from the brink and restore the health of the ecosystem. Meanwhile, I am looking forward to seeing the CRE osprey colony in full swing next spring and, if fortunate, see another osprey-bunker banquet.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
I am deeply grateful to Drs. Paul Spitzer and Alan Poole for providing invaluable information on the CRE, its famed osprey colony, and the current menhaden crisis. Kris Rowe, wildlife photographer of rising prominence and renowned chef at Liv's Oyster Restaurant, in Old Saybrook, was extraordinarily helpful showing me the area and permitting the use of his spectacular photographs to tell this story.
COMING UP: The Florida Keys Hawk Watch—imagine seeing 301 ospreys in one hour!
#55
Watching Osprey Migrating at Hawk Mountain, Kempton, PA
October 1, 2014
Migrating osprey at Hawk Mountain.
The next few of blogs will continue looking at issues related to osprey migration as Orpheus, Odin, and Orion make their way down the Atlantic Flyway, following the mountain ranges south to Florida. Our first stop along the way is Hawk Mountain, PA, famous for its spectacular autumn hawk flights.
In 1929, year of the market crash, the Pennsylvania Game Commission put a hefty bounty on the goshawk's head, offering $5 per bird, and guns started blasting. Goshawks sometimes take game birds before the hunters get the chance, so the hunters aimed to eliminate them. Two years later, amateur ornithologist and budding conservationist Richard Pough went on an outing to "Hawk Mountain." Pough and friends were part of a new wave of conservation-minded college graduates opposed to the wholesale slaughter of wildlife predators, especially predatory birds, and he was horrified by what he found. Hunters were standing shoulder to shoulder all the way up the mountain trail shooting hundreds of passing hawks out of the sky for "sport."
Two distant migrating ospreys at Hawk Mountain.
Cleverly, Pough returned the next weekend, collected the carcasses, and lined them up in the woods for photographs. The sheer number of dead birds was appalling and he set out to publicize this massacre. He showed his photos around until they caught the attention of Rosalie Edge, a philanthropist and conservationist from New York. Edge purchased 1,400 acres in Kempton, PA just east of Allentown, creating the Hawk Mountain Sanctuaryin 1934. This was the first refuge for birds of prey and was opened to the public as a place to enjoy raptors.
Photo of dead raptors taken by Richard Pough. (Courtesy of Hawk Mountain.)
Today, Hawk Mountain is one of the foremost autumn hawk watches on the Eastern Flyway. During the fall migrations, sixteen species of raptors fly by the mountain, becoming concentrated as they pass. From August through December, hundreds of ospreys, hawks, and eagles migrate through on their way south.
Migrating ospreys avoid barriers like high mountain ranges, preferring to cut through valleys and concentrate along narrow pathways of land. In North America, all the major mountain chains run north-south. When cross winds hit these ridges, updrafts form enabling raptors to slope soar. (Courtesy of Hawk Mountain.)
Hawk Mountain is in the middle of the Kittatinny Ridge, a section of the Appalachian Mountain chain. The 300-mile-long Kittatinny Ridge extends from 60 miles north of New York City to 20 miles west of Chambersburg, Pennsylvania. In the autumn, osprey and other raptors from all over eastern Canada, New England, and New York, slope soar the length of the ridge to save energy.
Diurnal or daytime migrant raptors, like ospreys and other hawks, prefer to migrate on northwest winds after the passing of a cold front. (Courtesy of Hawk Mountain.)
Hawk Mountain is part of the Appalachian section of the Eastern Flyway. Ospreys heading for South American destinations funnel into Florida, cross flap their way to Cuba and Hispaniola, before crossing the rest of the Carribbean Sea for Venezuela.
The orange arrows indicate the route taken by east coast ospreys to Central and South America. Once in Venezuela, the ospreys fan out and go as far south as Brazil, the Pantanal wetlands, and perhaps Argentina. (Courtesy of Hawk Mountain.)
Hawk Mountain straddles the 300-miles-long Kittatinny Ridge, a part of the Appalachian Mountain chain. In autumn, the passage of a cold front is often followed by large movements of raptors past Hawk Mountain and down the Appalachian Mountains. (Courtesy of Hawk Mountain.)
Ospreys soar along updrafts and thermals to migrate long-distances while conserving energy. They will also fly across large water bodies and deserts using powered, flapping flight. Powered flights enable ospreys to take straighter, more direct routes across land and water. During migration, they fish daily in the early morning or late afternoons and sometimes fly with a meal.
Although ospreys typically migrate and live alone half the year, they sometimes migrate and overwinter in small loose groups of 3-4 birds. It's thought that such flocking enables ospreys to locate thermals and find schools of fish more efficiently while travelling or living in their wintering grounds.
In the northeast, ospreys migrate south from July through October. Decreasing day length in late summer induces Zugunruhe, or migratory restlessness, which strongly influences the timing of flights. In autumn, the passage of a cold front followed by northwest winds usually induces a large movement of raptors along the Appalachian Mountains. This is the time to see ospreys, hawks, eagles, falcons and other diurnal or daytime migrating raptors soaring along these mountain ridges.
Female Rough-legged Hawk (courtesy of Suan Hsi Yong).
Seasonal timing also varies by species. At Hawk Mountain, the peak passage of broad-winged hawks, which depend largely on thermal soaring, occurs in mid-September. Osprey, bald eagles, and kestrels are also early migrants. Large numbers of sharp-shinned hawks pass the mountain in late September and early October. The peak of red-tailed hawk migration occurs in early November.
The best times to view specific species. (Courtesy of Hawk Mountain.)
Pack lunches, sunscreen, warm clothes, binoculars, folding chair, and a spotting scope if you have one, and make a fun day of it! Better yet, enjoy their excellent lectures and programs and stay overnight. The area is well equipped for guests with everything from camping and country inns to motels and B&Bs. It's a three plus-hour drive each way from Lansing, but the spectacle is well worth it the trip.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
Coming up: A fantastic spectacle of nature—an osprey-menhaden banquet in Old Saybrook, CT.
#54
Fall Migration Continued: Endings and Beginnings
September 22, 2014
"Those who contemplate the beauty of the earth find reserves of strength
that will endure as long as life lasts. There is symbolic as well as actual beauty
in the migration of the birds, the ebb and flow of the tides,
the folded bud ready for the spring.
There is something infinitely healing in the repeated refrains of nature—
the assurance that dawn comes after night, and spring after the winter."
—Rachel Carson
Flat-bottom cumulus clouds indicating an avenue of thermals to soar on.
After eating their morning fish, migrating ospreys gravitate to areas where thermals form. When an osprey locates a thermal, it circles in it to maintain forward momentum as the rising air slowly carries it upward in a spiral. Migrating ospreys take cues from other hawks spiraling in thermals or updrafts and will fly over to ride on the same air mass. They also look for puffy, flat-bottomed cumulus clouds, another telltale sign of a thermal, which form as moisture in the air condenses over the thermal's column of rising air. On a good migrating day at hawk watches, there can be hundreds of hawks and ospreys swirling upward at the same time, looking like an avian tornado or "kettle."
A kettle of ospreys overhead.
Migration entails many costly risks for any bird; accidents, collisions, and predation. Only one third of this year's class of fledgling ospreys will survive their first round-trip migration back to the Finger Lakes in two to three years. After that, however, their mortality rate plummets to only 10%. Our Salt Point family already lost Oya, this year's eldest fledgling, after she collided with the dead stretch of telephone line by the railroad crossing. [NYSEG left the line up for swallows to perch on, but now plans to remove it to give the awkward osprey fledglings a clear flight path to Salmon Creek.]
Migration is also costly in terms of energy. Large birds like ospreys use more energy in flapping flight than smaller birds, making gliding a much more efficient form of travel. Migrating ospreys are consummate multitaskers, able to sleep and migrate at the same time by remaining in a state of "semi-sleep." Osprey migration researcher Rob Bierregaard found ospreys rest half their brain during their journeys.
An excellent Salt Point landing thanks to Suan Hsi Yong.
Although my days of observing Ophelia, Orpheus, and their latest brood at Salt Point are over for the season, the drama of their lives plays on. The osprey year is a continuous circle and they just raised their second successful brood in a row. To us autumn feels like an ending, but for the birds it is just another beginning.
Orion and Odin at their Salt Point nest by Suan Hsi Yong.
I will continue writing On Osprey Time over the winter to discuss the lives of ospreys, their population explosion on Cayuga Lake, the need for osprey platforms, and hopefully to report on a few osprey adventures in warmer climates. Thank you for following the exploits of Ophelia, Orpheus, Oya, Odin, and Orion at Salt Point this year!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
Enjoy Rob Bierregaard's essay about "one of the more spectacular natural wonders of the world"—Veracruz—A River (of Raptors) Runs Through It—a river of 5 million birds of prey all trying to get south for the winter.
COMING UP: Go osprey watching at Hawk Mountain NOW!
#53
Fall Migration Part 2
September 20, 2014
Ospreys are becoming such a common sight during the summer months on Cayuga Lake that it’s easy to forget that these “local” birds spend almost half their year in and around the coastal and inland waters of South America. (Sounds nice except ospreys continue to be shot in some parts of their range, particularly at fish farms in Latin America and South America.) The autumn migration marks the end of our osprey season and the beginning of another one far south.
The 2014 New England Osprey Migration as of September 15, 2014. This
map shows the positions of 13 satellite tagged ospreys by RobBierregaard,
showing the progress to date—check his website for migration updates.
During their fall migration, ospreys along the East Coast move southward in a broad swath that stretches from the coast inland several hundred miles. This flyway narrows at the tip of Florida and continues to Cuba and across Hispaniola. Some osprey remain in the Caribbean, but most make the 500-mile open water crossing, some flying to Venezuela, Here the osprey fan out southward travelling into the Amazon Basin and the Pantanal, the world's largest freshwater wetland, which stretches across Brazil, Bolivia and Paraguay.
The Pantanal of south-central South America—the world's largest freshwater wetland (Alicia Yo).
There is no rush to travel in the autumn as there is in the spring and the ospreys wait for optimal weather. Few will fly in the rain, and easterly winds are not conducive to southward migration. Major migration flights virtually always happen on days when there is a westerly component to the wind—due west northeast are best, but even southwest winds can be good. By efficiently using solar energy, in the form of rising air currents or thermal columns, ospreys are able to fly long distances fast and effortlessly.
Example of a thermal column between the ground and a cumulus cloud (A). The sun heats the ground, which warms the air above it (1). The bubble of hot air starts to rise (2) until a certain point. Due to its lower temperature, the mass condenses and eventually moves downward (3).
Two kinds of air currents hold ospreys and other hawks aloft—thermals and uplifts. Thermals are large columns of warm air that rise into the atmosphere when the morning air warms, expands, and grows less dense. Thermals form by the differential heating of the ground, where the air is a few degrees warmer in one spot than the air next to it, as happens along a coasts, shorelines, and ridges; next to rivers and lakes; and above mountains, plowed fields, highways or other patches where dark ground is beside lighter, leafy areas. (Thermals are also responsible for bumpy air flights as the currents can reach 10 miles per hour or more—to avoid them, take early morning or early evening flights, especially over deserts.)
The differential heating of the ground and its effect on air currents. Surfaces such as planted fields, meadows, and water tend to retain heat and cause descending air currents. Meanwhile rocky or sandy terrain, plowed fields, and barren land reflect heat and cause ascending air currents. (Courtesy of Weather.)
The other kind of rising air mass is called an updraft, caused by wind hitting a hard surface like a row of buildings or a mountain range and reflecting up. Ospreys spread their wings wide and let the rising air carry them higher and higher without needing to flap, so they conserve energy. When the air stops rising, they hold their wings back making their body arrow-shaped and cruise as far as they can without flapping, slowly but steadily losing altitude until they find another thermal or updraft.
Ospreys and other raptors use rising currents and columns of air currents to gain lift and fly without flapping their wings. Raptors “slope soar” by riding winds deflected up and over hills
and mountains. Birds “thermal soar” by circling in pockets of rising, warm air called thermals. Raptors ascend quickly to thousands of feet within thermals, and then glide in the direction
of their destination. Radar studies suggest that many raptors migrate at altitudes of 700
to 3,000 feet while soaring in thermals. (Borrowed from the Hawk Mountain Sanctuary.)
When steady winds are present, thermals can align in rows oriented according to the wind direction, forming avenues of thermals from which ospreys will soar for vast distances without wasting energy flapping. Ospreys again conserve energy by alternately using thermals to soar to great heights, then gliding forward and downward before catching the next thermal. Tagging studies show that they can travel up to 500 miles in a single day, although they typically average around 100 miles. Without this ability, ospreys could not migrate over enormous distances.
To be continued in Blog #54 Fall Migration: Endings and Beginnings.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
#52
Bye Bye Birdies: Fall Migration Part 1
September 12, 2014
(My apologies for the late posting of Blogs #52-53.)
Friday morning was the perfect end-of-the-season day to migrate for daytime travellers such as area eagles, ospreys, and hawks. Skies were clear and a steady northwest wind blew down the lake. Orpheus delivered the morning fish, a whole lake trout measuring at least 16 inches, to his offspring just before 7 am. He then flew to rest in the cottonwoods by Myer's lighthouse. Lake trout are back on the menu as the fish populations move in the lake. Soon the fish will prepare for the lake to turn over, adding oxygen to the waters and stirring up nutrients that would otherwise be lost to the bottom of the lake. This morning's trout is an important high-protein supplement to the usual fare of yellow perch, sunfish, and brown bullheads for the last few weeks. Orpheus slept until flying off past Ladoga Point at 8:45 am. I wish I'd known that would be my last sighting of him for this season.
Although perfectly capable of fishing, Orion spent most of her morning Friday in the nest begging. I find that many of the youngest osprey fledglings in non-colonial nests tend to prolong their dependency phase by acting babyish. The youngest must view the nest as a free meal and would rather beg there than catch its own meals. Odin has more drive to fish and only joins the others at the nest when she sees and hears Orpheus about to deliver a fish to the nest. Odin seems the opposite of Orion, fishing and playing at it every chance she gets. Awkward at first, Odin's progress is visible week by week. Orion is nearly as skilled at fishing as her sister, but prefers the easy way out instead of demonstrating her full capabilities.
The lake was getting rough and by 10 a.m., Odin was fishing up and down in the calmer waters of Salmon Creek as Orion sat in the nest occasionally chirping and begging. When I returned an hour and a half later with my mentor, and world-renowned expert on ospreys, Dr. Alan Poole, to show off Odin and Orion, they were gone.
The strong northwest wind had a chill and even though the skies were clear blue, the heavy chop discouraged ospreys from fishing. It was the perfect day to migrate and with an all-knowing twinkle in his eye, Alan said confidently that they had left and I knew in my heat he was right. The literature says family members migrate on their own timescales when ready, but I guess it is not unusual for several members to leave on the same day as the juveniles did last year as well.
Even though I feel certain they have migrated, I will keep up my vigil at Salt Point, looking for the ospreys at strategic times and in their favorite places daily for the next two weeks to insure they have left the area. Juveniles are notorious for roaming around and returning to the nest before finally leaving on migration, and this two-week buffer should be enough if Odin or Orion is off exploring the region before leaving.
It is bittersweet to come to Salt Point now, as it seems too quiet without the ospreys chirping and begging. The scolding kingfishers chatter and chase each other from tree to tree along the point having just lost their favorite snag a few weeks ago to one final storm. Salt Point's iconic snag had been the focus many area artists through the years, such as Trish Coonrod. Once shared
Painting of snag at Salt Point by Trish Coonrod.
between the kingfishers and ospreys, the broken snag was too short for the osprey to hunt from and the kingfishers claimed it theirs. The long-standing remnant of a cottonwood from the International Salt days, broken in half last winter, finally lost its battle to the lake and is now just a stump.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#51
Hidden Dangers in the Osprey Nest
September 9, 2014
Odin and Orion are fishing daily for themselves, but they still have much to learn and a few more weeks to perfect their skills. The fledglings are well on their way to becoming independent
Orpheus brings his offspring a small lake trout for their breakfast.
juveniles although they still meet back at the nest at least four times a day for Orpheus’s delivery of lake trout, yellow perch, or brown catfish. Odin considers herself top dog and usually takes the
Orion and Odin scramble for the trout.
first fish of the day, but Orion eventually gets her fair share by sunset. Whichever fledgling grabs the fish first after Orpheus delivers it will hunch her shoulders and spread her wings over the fish
Odin grabs the fish.
to keep her sister away. This act of mantling, hiding recently caught prey from would be thieves, is a common ploy of hawks and eagles. If the fledglings have not caught enough for themselves
Orion makes a play for the trout as Odin cries in protest..
on top of Orpheus supplements, they will go to sleep hungry. This is a time of delicate balancing between Orpheus trying to keep his offspring nourished and yet encourage them to fish indecently.
Odin mantles the fish and will not let Orion near it.
Just after the osprey season ends, I will take another round of photos of all the nests around the lake and report ones that present potential fire hazards or have visible fishing line in them and report problematic nests to NYSEG. They do their best to address these issues and even clean out osprey nests of dangerous items whenever possible.
In Blog #3 I addressed the osprey’s notorious reputation for decorating their nests with all sorts of human debris, animal bones, and ornamental plant materials. Unfortunately, they also like to collect fishing line, plastic netting, nylon roping, bailing twine, and other items, which pose strangulation threats to the nestlings.
Ospreys aren’t the only birds at risk from fishing line and these other materials. Kingfishers, ducks, herons, loons, merganser, gulls, and other birds of the water also get tangled in these dangerous cast-offs, typically found hanging from trees in popular fishing spots or lying around the shoreline.
Great Blue Heron tangled in fishing line and lure.
Two years ago, I found a kingfisher dangling from fishing line at Myers Park near the popular fishing benches and ever since, I have been trying to clean up all the fishing line I find lying around in the parks and hanging from trees or caught in snags along the shoreline. If the tangled line is too high up, I report it to the appropriate parks departments. Sometime this year, the Cayuga Bird Club’s Conservation Committee, of which I am a member, hopes to install fishing line recycling containers at Salt Point, Myers, Cass, Dryden Lake, and Stewart Park to help curb this growing problem.
The hazardous debris found under the Portland Point osprey nest in Lansing. Having these materials in the nest with hatchlings can pose serious strangulation and entanglement risks.
A few pieces of fishing line have fallen from the Salt Point osprey nest and more has been picked up below the nest, Thankfully, however, Ophelia does not seem keen on using it in her nest. However, I do see fishing line in some of the nests around the lake and also many shredded garbage bags. While observing the osprey nest at Portland Point last night, I noticed numerous nylon ropes and fishing line dangling from it and collected a pile of nylon rope and some bailing twine from below the nest. I will inform NYSEG and then will probably clean out this nest if possible.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#50
Salt Point Adventure Day: Monarchs and Ospreys
September 8, 2014
Yesterday, the Friends of Salt Point (FOSP) and Lansing Loves to Read (LLR) invited parents and children to join us for an outing at Salt Point. A crowd of about twenty parents, grandparents, and children joined us for a tour of the Monarch Waystation, the reading of a book on Monarchs butterflies, an introduction to of the Little Free Library, and a trip to the osprey platform. Fledgling
Parents and children looking at the ospreys in their nest.
Odin and Orion entertained us as we got close looks of them flying and calling from the nest with my spotting scopes. We had lots of fun by sitting by the lakeshore, hearing a story on ospreys, and making and eating Martha Stewart-worthy caterpillar snacks of skewered grapes, cherry tomatoes, and editable eyes.
Setting up spotting scopes for closer looks at the ospreys.
Robyn Bailey lead a very close, high-stakes contest of osprey calling and Odin and Orion (the two osprey fledglings in the nest) were very confused by all the chirping and begging. Oya Rieger
Salt Point volunteer, Oya Rieger, performing an impromptu osprey courtship dance for all.
made a delightful osprey mask with wiggly eyes and demonstrated her best osprey courtship dance, chirping and flapping and confusing the ospreys all the more. A good time was had by all!
Having fun as an osprey!
Each child took home a kit for making the mask at home, complete with feathers, a page to color showing the fledglings at their nest, and a copy of Awesome Ospreys by Donna Love.
A young osprey watcher.
I was especially delighted that Mary Anne Perks and her family, including her grandson, could join us from the Elmira area. Mary, a member of the Chemung Valley Audubon Society, generously gave me first 100 copies of Awesome Ospreys, an excellent and scientifically factual treatment of ospreys for ages 8-14 years old, to distribute to children in our region.
LLR’s Judy Hinderliter reading about the osprey Reluctant Ralph to the group.
Mary is my inspiration and I've since ordered more copies of Awesome Ospreys to help Mary and me fulfill our shared dream of educating our area's children and adults about the amazing, totally awesome ospreys. Each town library and elementary and middle school library in municipalities around the Cayuga Lake near osprey nests will get copies. And we will work with inspired teachers willing to study ospreys to ensure their classes can get out to see nearby osprey nests.
Mom and son watching the ospreys together.
Next spring and summer, FOSP plans to host more adventure days at Salt Point for the community—I hope you will join us!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#49
Summer Turns to Autumn
September 2, 2014
The Fall migration is in full swing as is evident by the great number of shorebirds and other species congregating in the Montezuma wetlands. The Montezuma National Wildlife Refuge is a crucial refueling and resting stop for migrating birds along the eastern flyway. Some birds have begun travelling south through our area and the shorebirds often stop at Salt Point and Myers. Lately Lesser Yellowlegs, Least and Solitary Sandpipers, and Semi-palmated Plovers have been here and at the Myers Spit in the early mornings, but they are very skittish and easily scared by people and dogs.
Spotted Sandpiper at Salt Point.
The other morning at dawn I was pleasantly surprised by a Magnolia Warbler and a Rose-breasted Grosbeak, both in trees by my parked car. After I rounded the bend by the north cove of Salt Point, a male American Redstart greeted me. I am not the best at identifying autumn warblers and fall short on some of the drab females, but redstarts are old friends. Still flashing their bright yellow feathers as they undulate low over the meadow are the seed-eating American Goldfinches, whose uplifting songs always make me smile. They are the last birds of the season to nest, and when the weed seeds ripen at summer’s end, the young goldfinch have plenty to feast on.
Out in the north cove a Ring-billed Gull rests on the red and white buoy, but not for long. Once the sun is up, a Double-crested Cormorant takes its place. The Cormorant will perch there after fishing to hold out his wings to dry. Common Mergansers, Blue-winged Teal, and Black Ducks find shelter from the pesky Canada Geese in the cove, while Salmon Creek attracts Wood Ducks, Hooded Mergansers, and Green-winged Teal, along with the ubiquitous geese.
Great-blue Herons and the secretive Green Herons stalk the north creek side and Spotted Sandpipers patrol the uplands closer to the railroad bridge. It seems like the screeching Kingfishers and crying Killdeers create their own dramas out on the point. It seems late in the season for their noisy territorial disputes.
Speaking of noisy birds, Odin and Orion take the prize. Orion, the younger of the two, spends a fair amount of her time begging for food at the top of her lungs instead of fishing for herself. Odin will join her and beg if she see Orpheus fishing over the water. Any visitor to the platform can attest that the youngsters can beg loudly and have a special ear-piercing cry for when they are especially stressed. Orion has a way of working herself up into a tizzy, pulling out all stops, fluffing her feathers and holding her wings out in the ultimate of osprey begging postures. Orpheus encourages his daughters to fish by giving them ample food provided they subsidize it with a few catches of their own each day. Odin has no problem fishing and readily does so. Orion is coming along and makes daily attempts, some successful, but she makes it clear she would still prefer to be fed.
Orion begging for her dinner as demonstratively as she can.
The number of intruder ospreys visiting the nest has dropped dramatically in the last few weeks as many northern ospreys have already left on migrations. Summer evenings, after sunset, like tonight, are when the perch bite in the north cove. Catfish and yellow perch fill the pails of those fishing by the dwindling light. Those fishing have had an inordinate number of bites and bait lost to the invasive Round Gobie. Apparently this minnow-sized bug-eyed illegal immigrant from Russia is showing up along our shores this summer and we have no way to counter the gobie’s spread.
Round Gobie (Courtesy of DEC)
No one can predict what the Round Gobies’ ultimate ecological effect will be in Cayuga Lake. Every body of water has a different mix of species and the lake’s response to the introduction of the gobies is not predictable yet. I do know that they are aggressive little bait-robbers and are quick at stealing off your hooks.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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“Myers” the Monarch at it’s new home at Salt Point.
This weekend a friend, Suan Hsi Yong,found a small monarch caterpillar in an unlikely spot downtown where it probably would not survive. He put out a message on the Cayuga birder’s list serve asking if someone could rescue it. FOSP member Sue and son Jason Ruoff rescued it and released it behind the official Monarch Waystation in the field planted with milkweed and other butterfly-attracting plants at Salt Point. We’ve been keeping an eye on it and it is quickly increasing in size. Thank you Sue, Jason, and Suan and to all who wrote in with concern for the caterpillar.
#48
Monarch Waystation
August 28, 2014
Look for this sign by the Dog station as you enter Salt Point.
I am sure most visitors to Salt Point this summer have seen the milkweed in the meadow and the Monarch Waystation sign near the the dog litter station on the trail out to the point.
Thanks to the efforts of Friends of Salt Point (FOSP) Sue Ruoff, Salt Point is now listed in the Monarch Waystation registry under the Monarch Waystation Program. Salt Point is officially Waystation #8782. If you put the number in the search function, you will see our listing. This website offers a trove of information on monarchs from their life history, classroom projects, conservation, and galleries of gorgeous photos and videos to butterfly gardening, research projects, and monarch tagging. FOSP has planted butterfly-attracting plants throughout Salt Point and we hope to continue to attract these amusing, alluring, and essential creatures year after year for the delight of all.
Enjoy every moment outdoors as the summer draws to a close. It’s a great time to see Monarchs and other butterflies in the meadows at Salt Point. It’s also a wonderful time to relax by Salt Point’s Little Free Library. The library is a brightly colored box mounted next to a Leopold bench in the north cove by the woodpecker willow tree. Sit on a bench and enjoy the books, returning them as you leave for others to read. This ingenious system is another one of Sue’s contributions to the community of Salt Point.
Visitors to Salt Point enjoying the books from the Little Free Library.
Keep visiting the osprey family, as there is still plenty of action. They will not all migrate until probably the second or third week of September, but it is impossible to predict. Their progress in becoming independent is right on schedule and they are doing fine.
Ophelia has left for her wintering grounds and will hopefully return to her nest at Salt Point around April 5, 2015. Fledges Odin and Orion seem to be having the grandest time sailing and soaring in the winds. These days, they spend less time in the nest and more time playing in the air or attempting to fish off the point or in the creek. Often the use the cottonwoods lining both sides of Salmon Creek to perch, hunt, and eat their slippery catches. You can usually hear their frequent high-pitched calls, although I swear ospreys can be ventriloquists, and it is often hard to pin down the direction the calls originate from.
Orpheus continues bring fresh fish to his daughters on a regular basis, although the frequency is much reduced no that the young are also fishing. He’ll deliver a fish about every 3.5-4 hours, usually announcing grabbing talons as the fledges vie for the fish. By then Orpheus usually flees the fray and takes off. Odin and Orion rarely share although sometimes they manage to split the meal.
Odin fishing from a perch.
Just like the chicks last year, Orion has gotten a fish stuck on her foot a few times. It’s quite humorous to watch her try to shake it off, fly with it, while at the same time try to eat it like a popsicle. Odin also has had her share of stuck fish, but is more skilled at shaking them off.
Odin about to fly.
What a summer it’s been and we’ve still a few weeks to enjoy the osprey. Whenever there’s wind, the ospreys put on aerial acrobatic displays and it’s a great time to watch them. Between 5:30 pm and sunset is also a good time to watch the fish, fly, fool around, and feed. See you out the point!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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p.s. There is a sunflower field on Water Wagon Road, Lansing, which is worthy of Van Gogh. The flowers were planted in memory of farmer, pilot, and developer John W. Hicks and the public is kindly invited to pick these gorgeous flowers. What an appropriate tribute and a gift to the community.
#47
Goodbye Ophelia
August 25, 2014
Ophelia left on migration today after raising her family this season. It was the perfect day to start her journey, 80°, clear, with only a slight breeze. Coincidentally, she also left on August 25 last year. I know that ospreys typically return in the spring on or around the same day every year. I wonder if they keep such a schedule on their fall migrations?
Ophelia, the Grand Dame of Salt Point.
Ospreys face many dangers during their long distance migrations, especially from electrocution, illegal shooting, and vehicle collision. Mortality rates during migration are high in young birds, but once a bird achieves adulthood, such as Ophelia, the mortality considerably less.
I can never quite tell if the fledges or Orpheus react in anyway to Ophelia leaving. Am I being anthropomorphic by thinking I observe a bit of confusion on the part of the youngsters? Orpheus seems to carry on as usual, catching fish and bringing them to the nest for his offspring. Now he is fishing at half the rate as before because the youngsters have begun fishing for themselves.
To ward off any sadness from her departure, I spent the day humming an old favorite from The Band:
"Ophelia"
Boards on the window, mail by the door
What would anybody leave so quickly for?
Ophelia - Where have you gone?
The old neighborhood just ain't the same
Nobody knows just what became of
Ophelia - tell me, what went wrong?
Was it somethin' that somebody said?
Mama, I know we broke the rules
Was somebody up against the law?
Honey, you know I'd die for you
Ashes of laughter, the coast is clear
Why do the best things always disappear
Like Ophelia - please darken my door
Was it somethin' that somebody said?
Honey, you know we broke the rules
Was somebody up against the law?
Honey, you know I'd die for you
They got your number, scared and runnin'
But I'm still waitin' for the second comin'
Of Ophelia - come back home
—Robbie Robertson
God speed my dear Ophelia! Until we meet next year!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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Ophelia, recorded by The Band, appears on the album Northern Lights - Southern Cross released in 1975. The original configuration of The Band ended its touring career in 1976 with an elaborate live ballroom performance featuring numerous musical celebrities, which I had the honor of attending. This performance was immortalized in Martin Scorsese's 1978 documentary The Last Waltz, at which Ophelia was played one last time.
#46
Flying Fish
August 22-23, 2014
August 22: Odin caught her first fish! After three weeks of practice and two false starts, Odin (9 weeks old) was flying low and slowly up Salmon Creek when she suddenly lunged at the water with legs and talons fully extended and brought up a sucker. Once she had a secure hold on it, she brought the fish to a nearby snag to eat. Catching her first fish is a real milestone; it is her first complete taste of independence and life as a self-sufficient osprey. After playing with it as much as eating it, Odin sat with her prize for over an hour.
After the day’s monsoon-like rains subsided, she again tried her luck, successfully catching small suckers each time from the creek. Later, Orpheus pulled one 9 inch and one foot long brown bullhead from the creek and brought them home whole for the fledges. How they can possibly catch fish in a fast flowing stream opaque with sediment escapes me—one of the many marvels of the osprey. Young ospreys must learn not to drop their fish in flight or while maneuvering it on a perch, as they somehow lack the skill/knowledge to retrieve them. When a fish is dropped, they ospreys often cast a confused look down at their lost meal.
August 23: Another day of good fishing in bad conditions. Despite the low visibility from threatening thunderheads and extensive lake-wide sediment plumes from the storm runoff rushing into the lake, the ospreys seem to have no trouble getting meals. How they can possibly see in the muddy water astounds me! The ospreys are so finely attuned to their environment that they can detect the slightest changes and detect their prey despite these conditions, to the envy of many a perch lover.
Orion must have seen Orpheus fishing as she flew to the nest and started begging. A minute later she was joined by Odin who added to the chorus. When there is fishing in sight, the fledge’s turn up the intensity of their chirps. Roughly three minutes later Orpheus flew into the nest to drop off a modest 8 inch yellow perch and immediately left. Odin grabbed it and took off flying around the platform and trees. Orion followed her and the two circled, playing “Catch My Perch,” for nearly a half hour. Halfway through the game they were joined by two young intruders, presumably from the Portland Point nest, who circled with the pair above the platform.
In an exciting show of flashing wings and feathers and loud chirps, the four large birds would swoop low over me, within yards of my head, darting far out to the lake, banking sharply around the cove and looping back around the nest. Several groups of Salt Point regulars (and their loyal pooches) passed by and were treated to a great display of aerial antics as the teenaged ospreys played in the wind. The four tore up the sky and made a racket flying in large figure eights and loop de loops over Myers Park, Salt Point, and the lake—everyone wanted that fish! The perch stayed in play for another five minutes after the intruders gave up until the nestmates took their game of keep-away to the cottonwoods.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#45
Meet Me at Salt Point
August 25, 2014
Over the last two summers, I have met many remarkable people from the Lansing community, the Finger Lakes region, and from different parts of the US and the world.
One special visitor, Buse Yildirim, from Istanbul, Turkey, stayed with her aunt and uncle, Friends of Salt Point (FOSP) members Oya and Robert Rieger, for a few weeks this summer while she studied science and creative writing for teens at Cornell’s summer program. When she was not engrossed in her creative writing, Buse spent many hours at Salt Point enjoying the views, the wild flowers, the fresh air, and, of course, the ospreys. Her aunt had told her the osprey’s life history and the thought of a bird migrating so far and yet returning each year fascinated her. She especially likes watching them fly, circling the lake, and take care of their young. “They look so beautiful as they fly, so much like the wind, so free,” Buse commented with her excellent command of the English language.
Even though Buse, who attends high school in Istanbul, Turkey, at FMV Nisantasi Isik Okullari and will graduate in 2016, has been to Lansing several times before, she was apprehensive at first to take classes at Cornell.
“It seemed so big and the kids in my class were from all over the world,” says Buse. “An automatic camaraderie brought the students quickly together and on the last day, we parted as friends in tears. It was so wonderful and I hope to come back to here.” We made Buse an honorary member of FOSP and hope to see her again soon.
Taking in the fresh air, Buse Yildirim, from Istanbul, Turkey, appreciates the beauty of Salt Point.
Another pair of special visitors, birders Carol Creech and Rebecca Alexander, drove from South Carolina to Salt Point in August to see our ospreys. Followers of Cornell’s red-tail hawk and osprey cams, they discovered the On Osprey Time blog and are now loyal readers. After writing me and setting a date to meet, we spent a wonderful morning watching Ophelia, Orpheus, Odin, and Orion playing on the wind. Putting on quite a show for our visitors, the ospreys demonstrated their finest aerial acrobatics, spectacular fishing dives, and loudest calling. At one point, a pair of intruding ospreys checking out the nest for occupants came too close, setting off alarm calls from the nest and from Ophelia perched in a tree. When this did not suffice, Orpheus exploded on to the scene and chased the persistent intruders over the lake calling madly until they gave up.
“We've watched ospreys at Lake Marion and Landsford Canal in SC and are just beginning to learn about them. This place [Salt Point] is amazing! Just wonderful! What a treat to get so close to the osprey!” exclaimed Carol. A group of long-time friends, Carol, Rebecca, and a few others have a goal of birding in all the state parks in SC, and now they are adding our ospreys and parks to their wish list.
Seeing so many ospreys nesting on utility poles and athletic field light fixtures is new to Carol and Rebecca as many ospreys living in their area still have the luxury of finding natural nest sites atop huge, long-lived cypress trees left standing in the inaccessible, ancient cypress swamps. After a week’s stay, birding and hiking the state park trails, enjoying local stores and restaurants, and touring our local osprey nests, they migrated back south with promises to return.
Osprey nesting in a cypress swamp at Lake Marion, SC.
I look forward to seeing these three women again and meeting more adventuresome travelers and ecotourists enjoying the many riches at Salt Point—you never know what sort of adventure lies ahead.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
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#44
Teenage Behavior
August 22, 2014
Orion was on the diagonal perch as I arrived this morning, a spot usually reserved for her parents. From over the lake I hear Orpheus call out that a fish is on its way, Orion eagerly calls back as does Odin as he flies from the nearby cottonwood. They meet at the nest, where Orpheus leaves the nine-inch yellow perch before flying off. Immediately Odin commands the fish, standing over it and blocking all access to it by mantling his wings around it. Orion protests vehemently to no avail as Odin tugs away at the fish and easily consumes it all. A boney perch doesn’t last long amongst the ospreys. Orion kept begging throughout the meal, but Odin did not take pity. She ate her fill and flew to the lake to wash her talons.
Odin flew back over the creek, making practice dives into the water until the game wore thin. Meanwhile, Orion quickly devoured whatever fish Odin left behind, but she was obviously not satisfied as she continued to utter occasional begging cries. Odin returned to the nest and the two young birds, one on the diagonal perch and the other on the horizontal platform support, continued to beg separately and in unison, calling out to their father to bring more fish.
Odin and Orion have both been flying over the water frequently, practicing movements required in fishing, and probably learning how to identify prey and judge distances through the water as they move. They spend hours atop trees staring in the water, following the movements below. Unlike last year’s brood, which were behind schedule from the start and had to play “Beat the Clock” and “Catch Up” all season, this year’s gang has the usual amount time to hone their fishing skills before migration.
Young ospreys seem to have one thing on their minds—fish—and will go to great lengths to get them. In colonies, fledges commonly beg for fish at neighboring nests and can be seen flying from nest to nest for handouts.
Once they are able to fish for themselves, between 7-17 weeks after fledging, the young ospreys will be considered juveniles and will be ready for their journeys ahead. With the advent of GPS technologies, researchers are now learning about the pre-migratory and migratory movements of ospreys and what they do in the winter. Robb Bierregaard, a leader in using satellite telemetry to track osprey movements, found that instead of leaving directly on migration, some juveniles like to take practice runs, travelling up to a few hundred miles only to return to the nest before migrating.
Tracking map of 16 ospreys by Robb Bierregaard.
Each young osprey will leave on migration and travel alone when the time is right. No one knows what environmental, physiological, or biochemical cues tell them to leave or how they know where they are going, over 2-4 thousand miles away. They will migrate alone although they may form loose groups while travelling or fishing. Even more miraculously, after staying in their wintering grounds for two to three years and becoming physically mature, the males will return to their natal nest sites to start find a home nearby for their own families. The females also return to the same general area looking for mates, although they may travel a few hundred miles in the process.
The young osprey spend these early years physically maturating and fine-tuning their fishing skills. Young birds usually start hunting by perching near water and diving down to capture fish. The spectacular high-altitude aerial hovering and plunge diving that ospreys are famous for take a few years to perfect. Fortunately, they only have their own mouths to feed during this learning process.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
#43
Ophelia, Part 2
August 21, 2014
Against the clear blue sky, the color of cornflowers, a young osprey flies. The golden light of the setting sun gives everything a special glint and Ophelia’s breast an elegant glow. After all these weeks of watching, one feels like one knows these birds, but these have only been glimpses of their full life. (There is only scant information on what their lives are like in the winter.)
Ophelia lazily taking a stretch, obviously she’s not ready to migrate today.
I, and others, have watched Ophelia and Orpheus all season as we all did last year, seeing the pair court, nest, and cooperatively fledge three chicks. We have all been entertained by the antics of the youngsters exploring the air and water. And we start to feel as though we know these birds, understand these birds, and see these bird for what they are. Many of us feel we have come to know these ospreys as individuals, members of a family, and as a species. And, here is so much more to learn!
As the sun sets on a fascinating day filled with the magic and majesty of flight, the words of theoretical physicist, teacher, raconteur, and musician Richard P. Feynman (1918–1988) ring true. Like a modern-day Renaissance man, Feynman assisted in the development of the atomic bomb, expanded the understanding of quantum electrodynamics, translated Mayan hieroglyphics, and was an eloquent scientist. Feynman’s many lectures and interviews helped popularize quantum physics, much as Carl Sagan made astronomy accessible to the layperson.
Feynman related how he learned scientific observation from his father:
You can know the name of a bird in all the languages of the world,
but when you are finished, you will know absolutely nothing about the bird…
So let’s look at the bird and see what it’s doing—that’s what really counts.
(I learned very early the difference between knowing the name
of something and knowing something.)
—Richard P. Feynman, Making of a Scientist
We are so fortunate to be able to watch the ospreys live their everyday lives at Salt Point. By doing so, we begin to really see them and come to know them. Enjoy Ophelia’s last few days before she flies off to the next chapter of her life.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#42
Ophelia
August 21, 2014
Ophelia, the grand dame of Salt Point, is reaching the end of her parental duties for the year and is readying for her 2K-4K migration to the Caribbean, Central America, or South America. A single osprey can log more than 160,000 miles migrating during its 15-20 year lifetime!
If you’ll pardon my anthropomorphism, for now she looks satisfied with the world as she sits high on the diagonal perch scanning the lake, perhaps watching for for her offspring.
Ophelia scans the lake while Odin comes in for a landing.
It’s been a long spring and summer for her, spending all her time nurturing and tending to her family. For the second year in a row, she and Orpheus raised three chicks to fledging, which is quite an accomplishment for a young pair of osprey—two being the normal brood size. Larger broods of 3-5 chicks are usually seen in older, more experienced pairs.
Ophelia flying with fish caught by Orpheus.
With her rearing job complete, she spends her time guarding the nest and catching the occasional fish for herself or the family. She’s been sitting in her nest for months and needs to get in shape for her journey ahead. She flies up and down the lake, getting her muscles back in shape, and spends much time preening in the nearby cottonwood, getting her feathers back in shape after such long neglect.
Out on the point, watching Ophelia fly around on the breeze while calling out to the chicks, perhaps encouraging them to join her, my quotidian worries fade. Sailing above me, she is the very picture of effortless grace, strength, and precision control. Moments later, she is soaring with total abandon, sparking a desire to join her. Oh, to fly! To feel the wind beneath your sails—that’s the stuff my dreams are made of.
One morning in the next week or so, she will take flight, soaring high into the north wind, letting it take her south through Pennsylvania. She’ll probably fly along the Kittatiny Ridge, down the Appalachians, over to the Atlantic coast to Florida and then southwest to Sanibel Island. The migrating osprey from up north do not mingle with the resident ospreys living in Florida, and instead leapfrog over them as they travel to Cuba, Haiti, and finally to Venezuela and elsewhere in South America. The juveniles will spend at least two years maturing before returning to their natal breeding ground. Orpheus and Ophelia will reunite at their nest every year.
Odin bathing just offshore at Salt Point in front of a crowd of onlookers. (iPhone image of Thomas Collum)
Visitors to Salt Point were entertained by Odin’s antics as he bathed within yards of us offshore. (The fledges have not learned to fear humans yet and allow close approaches.) Several of the appreciative onlookers were loyal observers of the Treman Marina Park osprey nest in Ithaca. They were thrilled to get so close to an osprey in Salt Point and were utterly amazed by his performance.
The winds transformed the threatening black skies into the pastel beginnings of a mesmerizing sunset. The changeability of the weather today, the infectious energy of the fledglings and their flights, and the many well-wishers that came regularly to see the progress of young Odin and Orion puts me in a celebratory, appreciative, yet reflective mood. As ecological activist Rachel Carson (1907-1964) reminds us “there is symbolic as well as actual beauty” all around us, everywhere we look in nature there is discovery, and a healing renewal.
"Those who contemplate the beauty of the earth find reserves of strength
that will endure as long as life lasts. There is symbolic as well as actual beauty
in the migration of the birds, the ebb and flow of the tides,
the folded bud ready for the spring.
There is something infinitely healing in the repeated refrains of nature—
the assurance that dawn comes after night, and spring after the winter."
—Rachel Carson
Just before migration birds tend to exhibit a growing restlessness. Ornithologists borrow from German to call this sensation Zugunruhe. I think of it as a nagging urge, an insistence at the biochemical level to take flight and keep going. The spring migration for all animals has an urgency to it, a reproductive imperative, lacking in the fall migration and I would guess the intensity of Zugunruhe also lessens in the autumn.
One of these mornings when conditions are just right, Ophelia will push off into the breeze and fly out over the lake with powerful strokes. Catching the north wind, she will glide along mountain ridges, river banks, and coastlines, fishing and riding thermals all day, as she follows an ancient sky highway to the south just as countless other generations before her have done.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#41
Ospreys Speak
August 17, 2014
Listening to the ospreys is like listening to people speaking a foreign language. After a while, you to grasp the general subject matter of their vocalizations, if not the specific messages. The basic vocalizations are simple—there are nest chirps, solicitations (food-begging), alarm and guarding calls, and excited, defensive screaming. However, there are many subtleties I have not learned. All of their calls vary with the individual, allowing the ospreys to recognize each other by voice. Superficially, the osprey language seems rather limited, but Ophelia and Orpheus have no problem expressing themselves and communicating.
CONVERSATIONAL: Osprey family members make many vocalizations as they interact with one another. In the nest, the low, softly chirped sounds of reassurance given between parents and chicks are the type universal in the animal kingdom and easy to interpret, as are Orpheus’ loud cries as he delivers a fish to his noisy family. The meaning of Ophelia’s loud, sudden, and harsh Cheerp!announcing danger and ordering her brood to lie pancaked inside the nest for safety’s sake is also unmistakable. Once the young are flying about and mobile, the chirps they issue become important in keeping the family in touch during the day.
Orange-eyed Orion peaking through the nest.
SOLICITATION OR BEGGING CALLS: Females and chicks give solicitation or food-begging calls to males when they are hungry and want fish or if a male is nearby with a fish and they want a share. These repetitive chirping cries, heard throughout the breeding season, sound like a series of high-pitched squeaky Cheeep! Cheeep! Cheeep!strung together. Begging calls may begin with quiet rounds that build in loudness and intensity the longer it takes the male to respond. These solicitation cries can be of three intensities from low to high: the more intense the need, the longer and shriller Ophelia’s cries become. At the highest level of solicitation, a female often assumes a submissive posture as she cries, holding her body horizontally, with her crest-feathers slightly erected and her wings held close to the body. Regardless of the intensity, these cries mean one thing, and one thing only, FEED ME! Now in their eighth week, Odin and Orion now beg quite effectively for themselves.
Fledgling giving begging call.
Ospreys are each individuals. different from each other. Some birds are nosier than others; some male ospreys have varying responses to their mates’ begging cries. Those males most responsive react immediately and surrender their fish. The least responsive males ignoring begging cries for hours on end. High intensity begging calls can become quite loud and unrelenting, and the longer a female is ignored, the more adamant she becomes. Considering the excellent quality of their hearing, it is difficult to understand how a male can disregard these urgent messages for long. Male ospreys seem subject to that very human trait of "selective hearing."
If a female is not fed enough by her mate, she may solicit food and even copulate with intruder ospreys, which is not in the best interest of her mate. Although ospreys usually mate for life, the rare separation ensues if a female is not feed adequately during incubation or if the clutch fails due to starvation. The longer osprey pairs are together, the more they learn to communicate and respond appropriately to their mates. It takes some males years to learn to share their catches with their mates. Better communication means more cooperation and more efficient nesting, successful breeding, and raising of the young.
GUARDING CALL and DEFENSE SCREAMS: Response to initial threats to the nest are often met with the Guarding Call, which escalates into full-blown Defensive Call if the threat persists. These calls are given by both sexes. In contrast to begging calls,, the osprey’s guarding and alarm calls are heeded immediately. These alarms are the ospreys’ first line of nest defense and are very effective.
Guard Calls, are a series of slow, whistled chirps, descending in pitch, sometimes followed by two or three more intensive wavering notes are usually given when an intruder ventures near the nest. Ophelia assumes a defensive upright posture with neck extended, and wings held slightly opened. These calls are given when a threat or an unwelcomed osprey comes to within 300-900 feet of the nest, and serve to warn the intruder that they will be attacked if the intruder persists.
If the intruder continues to get closer, the adults and grown chicks’ guard calls escalate into an alarm call with furious squeals—Cheereek! Cheereek! Cheereek!that intensify along with the threat. The screaming nest owner will assume a threatening posture with erect stance, neck extended, back feathers erected and wings partially opened and beating slowly. The frantic calls become higher pitched during fights. If highly threatened, an alarm call can grade into a harsh, rasping, guttural “ick-ick-ick.” If the intruder continues its threat, Orpheus will instigate a high-speed chase to drive the bird away. If a real threat approaches—such as an eagle, goshawk, or great-horned owl—the call becomes explosive.
Fledgling giving defensive “Don’t Mess With Me” call.
Males also give alarm calls—Cheereek! Cheereek! Cheereek! (although some say its pee-pee-pee!)—as part of their aerial courtship display, showing the many functions of this vocalization: attracting mates, claiming territory, and alerting neighbors and mates to danger. Communicating between themselves, the pair issues low, almost sweet chirps as a greeting at the nest.
When Ophelia is stressed, especially on hot afternoons, she often adds several rounds of “ick-ick-ick! ick-ick-ick! ick-ick-ick!” to the end of her begging cry—perhaps her way of muttering under her breath something about Orpheus being a slacker. Teenagers often step outside their bounds as they test every societal limit. Osprey teens, those fledges not yet independent of home, act up, showing off in the skies, and pretending to be braver than perhaps they really are when intruders come too close to the nest. Today, Orion was copying her stressed mother, adding ick-ick-ick! ick-ick-ick! ick-ick-ick! to her pleas for food. Unfortunately Orpheus was not around so I could not judge his reaction to this bit of teenage rebellion.
Understanding Osprey-Speak can be confusing in the beginning since some of their calls have double meanings. As is common throughout the animal world, defensive displays share many elements with breeding ones. The sounds may be the same, but the behavior and body position of the caller makes the intention clear.
SCREAMING CALL: To claim Ophelia’s full attention while he courts her, sky dancing and parading around with a fish or stick, Orpheus lets out a Screaming Call—Cheereek! Cheereek! Cheereek!—the same as the alarm call. When employing Cheereek! Cheereek! Cheereek!to attract Ophelia’s attention (instead of chasing her away), Orpheus morphs the call by taking away its defensive edge and performs his courtship maneuvers to entice and not scare her. In the beginning of the breeding season, listen and look for the courting rendition of Cheereek! Cheereek! Cheereek! You will have many opportunities later on to compare it to the osprey alarm calls.
One look says it all.
Listen to some of the osprey calls mentioned above available from All About Birds, the Cornell Lab of Ornithology’s on-line birding field guide. The Lab’s Macaulay Library has 41 recordings of ospreys from North and South America allowing you to compare calls from different individuals to hear variations in their delivery. The Macaulay Library is an outstanding resource enabling the public to explore the world's largest archive of wildlife biodiversity in sounds and videos. Besides being used for research and teaching, Hollywood has it on speed-dial. During the making of the film The Big Year, (pardon the short commercial in the beginning) the producers used the library’s resources extensively to insure they used the correct birdsongs and images.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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#40
Mid-August at Salt Point
August 14, 2014
Mid-August brings many changes to Salt Point as the breeding seasons for most plants and animals wind down for the year. The second broods of most birds have fledged, although lines of mergansers and ducklings still trail their mothers; fawns leap through the woods after their does; berries flavor the trails; and butterflies and wildflowers light-up the grasses throughout the Point. Spring’s constant musical warbles and songbird melodies have been replaced by crickets singing, insects buzzing and trilling, and nighttime serenading tree frogs. Swallows and dragonflies comb
Common nighthawks are recognizable by their white wing bars.
the meadows and creek for mosquitos and other flying insects, then bats and Common Nighthawks take their places as hunters at dusk. Crepuscular nighthawks are easiest seen flying around lighted lampposts at Myers Park on summer nights and over the creek at dawn and dusk. Famous for their prodigious capacity to consume insects, stomach contents analyses for one day showed that one common nighthawk captured over 500 mosquitoes and another ate 2,175 flying ants. Nighthawks are members of the goatsucker family (Caprimulgidae) and have little in common with true hawks, especially our most famous Salt Point hawk—the osprey (Pandion haliaetus).
Wide-mouth insectivorous Common Nightjars are fairly common in the summer.
(Photo courtesy of Audubon)
The remains of the iconic snag at the tip of Salt Point is still being used by the kingfishers and the osprey fledglings. Mink played along Salmon Creek in the beginning of the summer, but have not been seen lately, but beavers have been active. Amazingly, a river otter was spotted at the point this summer. Perhaps it is a survivor or offspring from the New York River Otter Project, which released otters in the Northern Montezuma Wetland Complex (MNWR) at the northern end of Cayuga Lake in November 2000.
August is also the month to start watching for seabirds, waterfowl, shorebirds, and other migrants from as far north as the Arctic tundra taking the Atlantic Coast Flyway south to winter along the eastern shores of South America. During their international flight, we are fortunate to have hundreds of thousands of migrants stop over for refueling at MNWR where we can observe them feeding on invertebrates, worms, and the “soup" or biofilm of microorganisms coating the mudflats. Many of these migrants also stop at Myers Spit, considered by ornithologists to be the most valuable local water bird real estate, with some spillover to the Salt Point shoreline.
Bring a field guide, binoculars or a scope, and the Birds of Salt Point checklist out to the point and start scanning the shores of Myers Spit and Salt Point for migrants. The smallest “peeps” or sandpipers are often along the sides and at the very tip of Myers Spit and Salt Point. Species to be watched for include Semipalmated Plovers; Dunlin; Long- and Short-billed Dowitchers’; Greater and Lesser Yellowlegs; sanderlings; and Least, Pectoral, Semipalmated, Solitary, Spotted Sandpipers. Caspian terns are easy to find flying off Salt Point with their raucous calls or lined-up facing the wind on Myers Spit.
Caspian Terns on the lakeshore.
Songbirds are more challenging to find in late summer as they no longer perform their dawn choruses and sing their way through the day. Red-eyed Vireo, wrens, and goldfinch are a few exceptions that still proclaim themselves with song well into summer. The red-eyed vireo is also called the "preacher bird," as it sings its song non-stop, nearly 20,000 times a day! Odd squeaky notes issued by begging young and peculiar songs sung by juvenile birds trying to learn their songs can be heard from the brush as you walk the trails at Salt Point. If you see a bird and you think it's recently fledged, look at its bill for a colored edge called the gape mark. If you see one, the youngster is probably not abandoned and its parents are somewhere close searching for food for the youngster.
August is also an excellent month to watch for butterflies and dragonflies throughout the point. Many areas have been planted with milkweeds, Joe-Pye Weed, and other plants providing food plants for caterpillars and nectar sources for butterflies. Dragonflies are also plentiful in the meadows and water’s edge.
An American Lady butterfly at Salt Point. (Courtesy of Vanessa Wright.)
Perhaps the biggest change over the summer has been in the osprey nest where three little hatchlings grew up to be three magnificent young ospreys. Oya, the eldest fledgling who perished
The Salt Point Three probably looked much like these hatchlings. (Photo courtesy of Doc Baldwin.)
on August 1, is missed yet her spirit lives on in the wings of his siblings—such is the cycle of life. Odin and Orion struggle in the wind to learn the finer points of flight and play-act fishing in the
The Salt Point Three—Odin, Oya, and Orion—all grown up and being fed by Ophelia.
lake. Their sky dives, tandem circles, and dances in the air are spectacular and their attempts at bathing and fishing comical. It's August at Salt Point and a delightful time to be outdoors.
Male Spotted Spreadwing (Courtesy of Meena Haribal)
Just now two male spotted-spreadwing damselflies flew past me on the shore. It's August at Salt Point and such a delightful time to be in the Finger Lakes.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
This email address is being protected from spambots. You need JavaScript enabled to view it.
The Cornell Lab of Ornithology offers a number of inexpensive webinar programs to help you become a better birder. Three upcoming courses are:
Shorebird ID series: August-September 2014
NEW Raptor ID Series: October-November 2014
Waterfowl ID series: November-December 2014
#39
Neighborly Ospreys and Great-Blue Herons
August 12, 2014
My soul is in the sky
—William Shakespeare
I compare how Odin (64 days) and Orion (61 days) look today to how last year’s three fledges—Robyn, Paulie, and Stevie—appeared on comparable days. Both sets of fledges have gorgeous plumes with the basic osprey coloring, complete with bandit’s mask, and an additional buff edge to their chocolate-colored feathers. The buff edges lack melanin, making them easily worn with use and age. Oya had a very slight necklace in comparison to his siblings. Odin and Orion, who have dense necklaces on their breasts.
Each of the fledgling’s chocolate brown feathers is tipped in buff, giving the young birds a spotted look.
The fledglings underwings and napes of their neck have a slight rufous wash left over from when they were chicks that adds to their beauty and brings out the burnt fox orange color of their eyes (adult eyes bright yellow). Their crowns and chests have distinctive markings that are useful, along with their behavior and size differential, in identifying individuals.
A close-up of a fledgling shows its elegant orange eyes and dark bandit mask.
I am working on blogs addressing the issues of osprey intruders at the nest, polygamy, and a few other juicy topics. However, I can’t let another minute of summer pass without talking about ospreys interacting with one of their most vociferous neighbors, the Great-blue Heron. Fear not, they are not going to kill each other (I hope) and the osprey will not drive the herons away. However, I am sure most of you have wondered as much if you’ve seen the osprey chase the heron or visa versa with the heron inevitably screaming bloody murder. If anything, it’s the heron that is the aggressor most of the time, unless it ventures too close to the osprey nest.
Just a few moments ago, a great-blue came from about a mile north of Salt Point and began fishing of the point’s north shore. Ospreys vary in temperament from being aggressive toward great-blue herons, to accepting them and visa versa. Ophelia, perched on the westernmost lakeside cottonwood, noticed its presence, but ignored it. The sun had just risen behind the cloud bank with only a hint of a breeze and the water was near flat, almost mirror-like. After slowly stalking the shore, moving it’s enormous limbs gracefully and purposefully, it stopped suddenly like a statue. The bird waited motionlessly for minutes until in one swift movement it stuck the glassy surface, dunking it’s head and coming back up with its throat and mouth distended with water and minnows.
Great-blue Heron flying low over Salmon Creek.
After gulping down the fish and expelling the water in one movement, the great-blue flew towards the osprey platform, giving its low guttural Kraaaaaak! Odin and Orion, sitting on the platform, cried out in warning and the heron slowly altered its course, giving the platform a wider birth. If this had taken place during April through June when great-blue herons sometimes prey on osprey eggs and young and try to steal their nests, the encounter would have been more heated, but now there is no conflict. The only other skirmishes occur if a great-blue is trying to steal an osprey’s fish. (Kleptoparasitism is common among fish eating birds—eagles commonly attempt to steal fish from ospreys and sometimes kill the osprey to get the fish.)
For the most part, great-blue herons and ospreys live side-by-side along shorelines throughout most of their North American ranges, competing only marginally, if at all, and tolerating each other as most interspecific neighbors do. They both nest in strong dead trees over water, but in the last few decades, ospreys prefer artificial sites. They both eat small fish, but since the ospreys have to carry their prey, they usually take fish weighing one-third and two-thirds of a pound. Great-blue herons fish by standing and striking and can eat just about anything it can ingest. Unlike ospreys that essentially only eat fish, great-blues will swallow nearly anything within striking distance, including fish, amphibians, reptiles, small mammals, insects, and other birds. The herons can also use their dagger-like bills to impale larger fish to break them into more manageable pieces. Finally, heron eggs are not prey for the piscovous osprey as they are for bald eagles, ravens, and crows.
Ospreys, on the other hand, hunt for larger prey and often farther off shore. Great-blue herons sometimes try to steal fish from the osprey and if a nest box is low to the water, an ownership contest can occur. An unusual and well-publicized osprey attack on a heron last year told of a near-death squabble over real estate. Posing no real threat to one another, the osprey and great-blue heron have coexisted for eons, usually peaceably, each performing their separate and vital roles in the Cayuga Lake ecosystem we all share.
Sometimes the herons try to nest in osprey platforms before the hawks return north as do Canada Geese, but the osprey usually drives them off. Just to be fair, ospreys have been known to take over heron rookeries. Beaver ponds are an important source of naturally occurring strong dead trees for eagle, heron, and osprey nests, and these precious trees often change hands.
Everybody chases each other at some point on the shoreline. This plucky duck must have caught the osprey by surprise.
The low guttural Kraaaak! of a great-blue heron stalking the bank of Salmon Creek brings me back to the here and now. The morning past, winds, waves, and clouds challenging Orpheus’ fishing skills and test the fledges’ landing skills. Odin and Orion are learning their aerial skills quickly and seem much more capable than last year’s fledges were at the same age, but the nuances of landing in the wind still evades them. Yesterday’s lesson was how many ospreys can sit on a flimsy stick at once. Today, it’s how many times must they circle the platform before they can get a firm grip.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
This email address is being protected from spambots. You need JavaScript enabled to view it.
#38
Around the Lake
August 10, 2014
My dear husband Dave and I just finished our mid-August inspections of the active and inactive osprey nests in the Cayuga Lake basin. I am unable to drive distances so Dave, who claims he’s not into birds (but makes exceptions for ospreys, eagles, and hawks), does the driving on these fun, but sometimes hair-raising inspections.
Osprey nests on Cayuga Lake. The nest on the west side is no longer active this year, but will hopefully produce a brood next year.
We were pleasantly surprised by all the wonderfully robust fledges we found and their healthy parents. Most nests around the lake fledged two or three chicks; with the older nests tending to produce the most fledges. Typically, ospreys have 2-4 fledges although five are possible in older mature pairs. Lansing’s Salt Point nest and Ithaca’s Treman Marina Park nest produced three fledglings each, although the eldest fledgling at Salt Point was killed in an accident. Lansing’s Portland Point nest and a new nest built on Cornell’s McGovern Soccer Complex off Game Farm Road fledged two healthy young birds. The Union Field’s pair, which got a late start nesting, and the new nest platform erected on Lansing’s Myers Hill will hopefully produce young next year.
Heading north up the east side offers continually picturesque views of the fields and the lake from Lansing up to the osprey-rich Route 90 Corridor, which goes from Levanna at the north to the Erie Canal’s first lock called “Mudd Lock.” Montezuma National Wildlife Refuge (MNWR) at
Female brooding two chicks in nest along Route 90. Each year the osprey nests get deeper. This one is about two feet deep and six to seven years old.
the top of the lake hosts many ospreys nesting along Routes 5/20, throughout the refuge, and nearby, taking advantage of the numerous local water bodies. The artificial platform in the North Spring Pool has an osprey camera that streams video into the refuge’s visitor’s center. There is also a lone active nest and three inactive new ones on the north west side of the lake. Like the other new inactive nests on the lake, they will most probably be used next season by the original pair or be taken over by a more dominant pair.
We visited every active and inactive nest in the basin, verifying the status and number of fledges per nest. These fledges were often begging for food while the adults fished, guarded the chicks, or went elsewhere. This year’s goal is to determine the number of active nests, new nests built, and the number of fledges produced in the Cayuga Lake Basin. With help, I’d like to expand the population data next year, but due to the inaccessibility of many nests, I am still puzzling over the best methodology. With out a jet pack, I am grounded. I’ll publish the final tally of osprey nesting activity and productivity for 2014 at the end of the season.
Of the many surprises we had at nest sites, three stood out this weekend. I had visited one new nest this year at least two dozen times and only rarely saw an adult nearby and never any evidence of chicks, although there was minor evidence of occupancy. We were shocked after so many “no shows” to find a crowded nest all weekend with the parents and two healthy fledges. The Beacon Bay Marina nest, built on top of a tower channel light, was battered, destroyed, and rebuilt repeatedly all summer. Apparently, this is the annual fate of this nest and will continue
Beacon Bay Marina nest.
to be until the platform is replaced. The current platform looks like it only has an inch or two of side support instead of the usual 4-inches—a $40-50 repair—and only a few sticks left. Regardless of these perpetual challenges, these intrepid ospreys were able to raised three fledges successfully.
Despite there only being a few sticks left after all the summer storms,
this nest fledged three healthy chicks. This photo was taken in June
when there were still ample sticks for the hatchlings.
The newest nest in the Ithaca area is on Cornell University’s McGovern Soccer Complex off Game Farm Road. Although this nest started late, after blowing down several times, it appeared the parents would be able to make up for lost time. And hopefully they will. However, the osprey male spent his weeks several weeks of aberrant aggression (personal communication). Initially the red-
Adult female on nest built on a light fixture in the middle of the McGovern soccer field. This nest is a fire hazard and Cornell University is keeping the lights off until the birds migrate. (Courtesy of Karl Sedlacek.)
tailed hawks were the territorial aggressors trying to chase the ospreys away, but they switched roles once the osprey chicks hatched and the male osprey went on the offense. His intense aggression towards the red-tails was interfering with his fishing duties and he became a less effective provider. After a day and a half of too little fish for the family, the female began leaving the chicks unattended for long periods (even though they were less than 30 days old) and began
Adult female and one of the two chicks at about 30 days old.
helping to fish and nest guard. After much concern from the nest watchers, the chicks both fledged around August 8th. Cornell University has agreed to keep the lights off while the ospreys are there and are exploring ways to perhaps install a safe artificial nesting platform for the ospreys.
Seeing osprey fish is always a challenge for me as I also try to identify and estimate the weight of the fish caught. I never tire of watching the mighty fish hawk as it hovers above the water and suddenly plunges downward with a dramatic splash, usually coming up with a meal.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#37
Hope Is the Thing with Feathers
August 5, 2014
On Friday morning, August 1, one of the osprey chicks was found horribly injured by the railroad tracks at Salt Point. (It was one of the two oldest chicks and I am still trying to find out.) She was taken immediately to the Janet L. Swanson Wildlife Health Center where she was examined and euthanized. From the blood and distribution of feathers, it looked like an aerial attack perhaps by an eagle (great horned owls usually attack at night) as her right shoulder was badly ripped. Alternatively, she could have hit something sharp in flight. The health center said they would send me the necropsy. Young osprey fledges are usually clumsy fliers, getting much too close to objects and are prone to accidents. Ospreys have roughly a 53% chance of surviving their first year, after that they have a 70-over 80% chance of survival.
Oya was such a magnificent young bird that my heart aches at her loss. Nature can be a harsh teacher. My sincere thanks to Brenda and David Lines for their fast rescue work, Melissa Groo for moral support, and Veterinary Assistant Marsha Zgola, Veterinary Technician Alice Van DeMark, and Dr. Noha Abou-Madifor their expert care.
Hope is the thing with feathers
That perches in the soul,
And sings the tune—without the words,
And never stops at all
—Emily Dickinson
If you find an injured animal, call the Swanson 607-253-3060.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
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The Janet L. Swanson Wildlife Health Center, located off Hungerford Hill Road, Ithaca, depends on donations from the public to fulfill their mission of conserving wildlife through veterinary care, education, and environmental health studies.
#36
Flying Jewels of Salt Point
July 29, 2014
A male Twelve-spotted Skimmer found at Salt Point. (Courtesy of Meena Haribal)
The flying jewels of summer at Salt Point are the harmless the dragonflies and damselflies (collectively they are odonates or “odes” for short). They are as varied as their colorful names imply—Ebony Jewelwing, Spotted Spreadwing, Slender Spreadwing, Tule Bluet, Familiar Bluet, Eastern Forktail, Fragile Forktail, Twelve-spotted Skimmer, Widow Skimmer, Eastern Pondhawk, Blue Dasher, Spot-winged Glider, Wandering Glider. Although odes can be found in many months of the year, they are most plentiful in June through August, when many of these gorgeous, often iridescent, inquisitive insects can be found along the water’s edge at Salt Point as they hunt for mosquitos and other insects and search for mates.
A male Widow Skimmer at Salt Point. (Courtesy of Meena Haribal)
The bold Blue Dasher (Pachydiplax longipennis) in particular, patrols the lakeshore and meadows, flying back and forth in the late afternoon. The males have lovely peacock blue bodies with fluorescent green eyes with bluish-green goggles. Looking completely different, as the odonates tend to do, the females have a yellowish body with reddish brown goggles. It is thought that the different colored goggles on the sexes indicate they hunt in different habitats. Odonates are magnificent aerialists, and are able to maneuver like hummingbirds, flying both forwards, backwards, or hovering. They can also fly at speeds of up to 50 mph, and can stop short or change direction equally fast. Blue Dashers, as do many dragonflies, allow you to get quite close to them and are often found perching and guarding its territory or hunting. Males often spend considerable time squabbling with each other over preferred perches with the best view.
Odonate lives depend on their vision. They have a mix of compound and simple eyes with a major section of their brain dedicated to neurons specific to vision. Due to their unique “wiring” odes are able to see in many directions at once and each eye can function independently. Researchers are still trying to understand how the insect’s brain functions and can process so much information at once. Next time you see a perched dragonfly, follow their line of sight. They usually keep an eye on you while searching for other predators, mates, or meals at the same time.
“One evening I was watching and photographing a female Blue Dasher, said Meena. I was photographing her from the left side and a male dasher was courting and displaying for her on her right side. She kept an eye on me to make sure I won’t harm her, but also kept tabs on how well the male danced. How amazing it would be if humans could do that!”
Male Blue Dasher (Courtesy of Meena Haribal)
Female Blue Dasher (Courtesy of Meena Haribal)
Colorful butterflies also abound on the wildflowers gracing Salt Point, which I hope to address in a future blog. Much effort over the last two years by Friends of Salt Point’s Sue Ruoff and Katrina Binkewicz has resulted in meadows of native milkweeds, butterfly weed, Joe Pye weed, and many other flowers at Salt Point to attract and host of variety of native butterflies. These plants provide food and habitat for many gorgeous species as they fulfill their life cycles, metamorphosing from larvae and pupae to flying adults. Around the osprey platform, Variegated Fritillary (Euptoieta Claudia) and Monarchs (Danaus plexippus) alight on blooms, slowly folding and unfolding their lovely wings in the sunlight. Sulphur-colored beauties flit about in the vegetation.
An abundance of other insects abound on the point, from ants to grasshoppers, katydids, cicada, and exotic looking beetles, providing food for countless birds and other animals and playing essential roles in the ecology of the area. Honeybees by the hundreds work the rosy pink flowers of the Bristly Locust (Robinia hispida) along the water’s edge, making these bushy weeds hum.
Honey bee at Salt Point.
As you plan your next outing to Salt Point, go to the Salt Point website and download the lists of damselflies, dragonflies, and butterflies and take them with you (found under “Salt Point Docs,” far left column on the Salt Point page < http://www.lansingrec.com/parks/salt-point >). Read about these stunning insects and watch their fascinating behaviors as they patrol their territories, play and chase each other, and hunt for prey and mates. The photographs in the checklist on damselflies and dragonflies of Salt Point are all from Dr. Meena Haribal’s new book mentioned in the postscript below.
Before I helped Meena edit her book, I’d always had an appreciation for the beauty of butterflies and moths and worked on the chemical ecology of insects in the lab. However, my whole perspective changed as I learned about damselflies and dragonflies through Meena’s descriptions and saw them though her lens—I became captivated by them. I had no inkling that these insects were so personable, approachable, and touchable. I knew little of their easily viewable and understandable behaviors, their fascinating lives, and their ecological roles. My life has been enriched by having damselflies and dragonflies a greater part of it.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
For more information on damselflies and dragonflies, please read: Where to find Damselflies and Dragonflies, In the Cayuga Lake Region and the Vicinity, by Meena Haribal. This unique book provides more than 400 stunning photographs of the over 100 species of odonates (damselflies and dragonflies) found in in the Finger Lakes region with tips on where and when to find them and descriptions of their fascinating behaviors. To order, contact Meena at <This email address is being protected from spambots. You need JavaScript enabled to view it.;.
Lots of information is available online about butterflies and odonates on line and at the bookstore at Wild Birds Unlimited at Sapsucker Woods, 159 Sapsucker Woods Road, Ithaca. Buy locally and support their excellent assortment of children’s and adult books on birds, animals of all sorts, plants, nature, all sorts of excellent birding paraphernalia and equipment.
#35
Birds Are a Miracle
July 27, 2014
Birds are a miracle because they prove to us there is a finer,
simpler state of being which we may strive to attain.
—Doug Coupland
Ospreys not only show us, they also prove to us there is a finer, simpler state of being. In the evening stillness, a half hour or so before sunset, the wind fades, the waves calm, rhythmically lapping against the shore, and a sense of peace descends like a mist. The sun light continually changes as clouds pass over it and play with its rays. Orpheus, perched on the platform and scanning the horizon, is abruptly reminded by his chicks that there is still time for one more—the last fish of the day—so that they can go to sleep with their crops bulging with fish. Orpheus pushes off the platform silently with his powerful legs and sets to work.
Lines of mergansers fly across the broiling sun in a real Kodak moment. The red setting sun hung from a cloud like an apple from a tree. Orpheus flew straight to the nest, crossing the path of the fiery red orb and its path of ruby light that miraculously leads to my spot on the shore. Orpheus carries an eight or so inch Pumpkinseed, a very distinctive member of the sunfish family, in his right talon and his family cheers (or rather chirps) enthusiastically at his triumphant return.
Flying high as he approached the nest, he began “helicoptering” as he displayed his catch, crying out for his family to watch, and acting like he was courting. As if embroiled in an enticing tango, Orpheus hovered with the fish, chirping and showing off his prize to all. Suddenly, he’d drop ten to twenty feet in altitude towards the nest and repeat the dance again as if he was courting his mate. Finally in one fluid movement, as he neared the nest, he braked with his tail, alighted on the nest long enough to drop off the fish, and flew off. It seemed like one of those perfect teaching moments when you think you might have gotten through. Regardless, it was a expert demonstration, whatever it’s purpose, and a nice way for his family to end the day.
Each osprey plays a vital role in maintaining the ecological health and balance of the lake. Humans have only just scratched the surface of comprehending the complexities of the natural world and the interrelated cycles of life. Orpheus scans the horizon, looking at peace with the world, but ever vigilant.
It’s been a breezy day, perfect for flight practice. Oya and Orion open their wings and jumping at the same time and chaos ensues. Refolding sounds easier than it looks, at least from a chick’s viewpoint. Orion has barely gotten to flap lately with his siblings hogging the nest with their practicing and probably has no idea how long his wings really are. His proprioception or his sense of the relative position and size of his body parts and the strength it takes to move them is still developing. To top that off, when his wings are out, his feathers tangle with twigs and siblings in the crowded nest and care must be taken to insure their safe return.
Preening is essential after such commotion to put everything back in place and to do a good job takes more time than the chicks seem to have patience for. Instead of looking sleek and neatly coiffed when done, the chicks often have feathers going every which way, requiring more effort to smooth them all down. Odin is just now getting the hang of long preening sessions to do the job correctly. On numerous occasions, when the gang is tending to its needs, Ophelia’s gotten slapped in the face by an errant wing or two, but takes it in stride like the good mother she is and moves to the diagonal perch.
Ophelia flies to the diagonal perch to give the fledges more room in the nest.
Flapping northward up the shoreline, just after noon, Orpheus followed the cliffs. After banking in a wide circle over the lake and heading back toward the nest, he suddenly stopped mid-air over the shallows. Something had caught his eye and he remained suspended. When seen from below, ospreys are white and look black from above. Much like Neruda’s Harris’ Hawk Parabuteo unicinctus, Orpheus hung by a thread, but there was no thread. With target locked, he plunged like a stone, going from 0-40 mph in milliseconds; the black talons barely visible as they are explode forward to grab the prey.
from Harris’ Hawk
Parabuteo unicinctus
I saw the white falcon suspended
from the sky as if by a thread,
but there was no thread:
the white falcon fluttered.
The movement was snowy,
its great white wings flapped,
inside it the fire leapt
like a consuming bonfire:
hunger sharpened the steel,
the black cyclone of its talons:
it prepared the blind blood
to plunge like a stone:
The youngsters could see Orpheus approach with the fish and all three greet him with great fanfare whistling and chirping as loud as they could, begging for food. Until the chicks can fish for themselves, begging is the only means they have to get food.
Merganser danced on the water, splashing noisily as they ran for take off. Great cumulonimbus storm clouds move in from the north, looking ripe to unload. Lazy summer days like today are such a gift. Life at the osprey nest runs at its own slow pace—on osprey time—with everything revolving around Orpheus and when he delivers the nest fish. Living on osprey time is a meditation. Give up what is expected of you and just be.
Now that the chicks are beginning to fledge, Ophelia can leave them alone long enough to fish and has begun bringing the occasional meal back to the nest if Orpheus falls behind schedule. However, the family is still very much dependent on Orpheus to supply most of the food and, other than their begging for food, they “patiently” wait for his deliveries. Ophelia’s role in supplying food may become more important over the next week or so depending on Orpheus’ ability to satisfy the chicks’ need for fish. Orpheus is an excellent provider and rarely keeps his family waiting long between meals. However, in the heat of the day, when the temperatures breach 85 and above, he is apt to rest in the shade, making every one wait until it cools down before he fishes. Ophelia does not fish then either, although she could, preferring to stay near the nest.
While cloud cover, sun brightness, and precipitation affect visibility while fishing, it is the wind speed and water-surface conditions—calm, rippled, or choppy— that impact the osprey’s hunting success the most. As wind speed increase, ospreys glide more and spend less energy in flapping flight, but hunting bouts become longer and less successful. Hunting in winds over 15.8 mph is not energetically profitable. In general, more fish are caught in sun than shade, and the calmer the water, the better.
On a good day, Orpheus can easily catch a fish in twenty minutes, eat his share, and have the rest at the nest within a half hour. Foul conditions, especially waves, can lengthen fishing times, but his efforts seldom last more than forty minutes. If the fishing is poor, he does not waste his energy. Often Salmon Creek and the coves around Salt Point and Ladoga Point provide calm waters while the winds drive waves on the rest of the lake, giving Orpheus options. The coves also provide clear waters when storms make Salmon Creek spew sediment into the lake.
Ospreys are excellent anglers. Statistics from research studies measured their remarkable skill. In one study, 82% of 639 fishing attempts were successful—56% on the first dive! In another study, the average time spent fishing per catch was only 11.8 min.—something to think about next time you cast your line in the water. Ospreys catch fish on at least 1 in every 4 dives, with success rates sometimes as high as 70 percent. The numbers of dives are highest at dawn and dusk and usually improve with the experience of the bird.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#34
How Ospreys Fly, Part II
July 26, 2014
Controlling shape of wind
The Bernouli principle is only a partial physical explanation of bird flight. Unlike the rigid wings of airplanes, bird wings continuously change shape to control flight. This changeability allows the osprey to slow down, speed up, and even remain paused hovering, while combing the waters below for food. When soaring the wings are spread out, and the primaries held out straight to maximize lift. If the osprey spots prey, it will circle, or ring up, until it reaches an
Ospreys change their wing shape according to their needs. Here they are bent for flapping.
elevation of several hundred feet. The bird will then wind hovers, before partially folding back its wings, reducing its drag profile and allowing it to accelerate at the start of its dive. With the wings folded back,
Wind hovering as the osprey makes ready to strike at its prey.
the center of gravity moves backwards and the bird is inclined downward. The tail also cocks downward, to help adjust to the downward angle of trajectory.
As the osprey’s dive continues, the primaries are progressively folded back and held tight to the body to further reduce drag. The osprey shifts its center of gravity farther back and increases its airspeed. Minor flicks and wrists of the primaries and tail provide thrust and course adjustments as the plummeting osprey tracks a fish like a guided missile.
Alula raised and wings, the bird takes on the shape of a guided missile.
There are several parts to a bird wing that enhance its flight capabilities. Scapular feathers overlay the wing feathers on the back when wings are folded and streamline the aerodynamic contours of the bird. Secondary feathers are attached to the forearm or radius and ulna. Ospreys have twenty, which give them considerable lift for soaring and gliding. Smaller birds, non soaring birds such as songbirds, can have as few as nine secondaries.
The primary feathers can also be upraised to allow the osprey to hover and remain motionless as it scouts for fish in the waters below.
Birds control their flight by adjusting their wing shape and feathers.
When a bird flaps, as opposed to gliding, its wings continue to develop lift as before, but the lift is rotated forward to provide thrust, which counteracts drag and increases its speed, which has the effect of also increasing lift to counteract its weight, allowing it to maintain height or to climb.
The leading edge of the top of the wrist joint or crook of the wing is called the alula and corresponds to a human thumb. Stiff concave feathers attached here come into play when the osprey does steep angled dives. When the alula is raised, it becomes a slat that forces an intense airstream along the top surface of the wing. This prevents stalling as the bird’s forward speed decreases and the angle of attack increases. When the angle of attack increases to the point that the osprey intentionally stalls and the airstream over the top of the wings breaks away from the surface of the wings and back. At that point, the osprey uses its outspread feet, tail, and wings to slow as it descends to a perch.
Bird using its wing and tail shapes and positions to control its flight—the wings supply the lift and the tail acts as a rudder.
The osprey’s tail, like its wings, acts as an airfoil generating both lift and drag. The stiff tail enables the bird to carry out the acrobatic, skilled aerial maneuvers crucial to their lifestyle. The wedge-shaped tail acts as a rudder. In flight the tail is kept folded reduce drag. When spread wide horizontally, the tail keeps the osprey level. When raised, the bird ascends. To dive, the osprey lowers its tail. When the tail is lowered sharply and abruptly, it brakes forward movement and aids in landing. Spreading the tail and sharply twisting it on side helps the osprey bank sharply. Finally, an osprey soaring in a thermal can open its tail so that it climbs faster.
The powerful leg and wing muscles of an osprey are able to carry live prey, weighing nearly as much as the bird, to its nest, often miles away.
Ospreys have extremely powerful legs, used for catching and carrying prey. Various birds use different techniques for becoming airborne. To take off, the osprey, like other hawks, uses its strong legs to leap upwards as they take flight with a powerful downward thrust of their wings.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
The mechanics of bird flight are fascinating and my cursory discussion does not do it justice. For more information on bird flight, please read How Birds Fly by David Goodnow and Birds in Flight: The Art and Science of How Birds Fly by Carrol L. Henderson. Hopefully they are in the local library. Support our local economy and by locally! Both books are available at Wildbirds Unlimited at the Cornell Lab of Ornithology, 149 Sapsucker Woods Road, Ithaca.
This blog, as do many of the others, features outstanding osprey photographs by Andy Morffew, a terrific fellow osprey follower and skilled photographer, who splits his year between the Gulf coast of Florida and Hampshire, England and travelling wherever the birds take him. Look for his biography on our upcoming Contributing Artists page on Salt Point website.
#33
How Osprey Fly, Part I
July 26, 2014
Because the Wright brothers and their predecessors were clever, they based their theories of flight and designs for aircraft on the aerodynamics of bird flight. Ospreys, like all birds, have numerous adaptations for flight. Strong, hollow bones decrease their total body weight making flight easier. Ospreys, because of their large size—nearly 6-foot wingspans—and the weight of the prey they carry, need a lot of space to take off and maneuver, rather like an airplane. Ospreys cannot make quick turns or fly in tight spaces like the Accipiters—Sharp-shinned and Cooper’s Hawks. Rather, ospreys are diving and soaring hawks, using their powerful wings to make stunning plunge dives after fish and able to migrate long distances by almost floating effortlessly on thermals.
Basic powered flight with wings bent at the wrists in the osprey’s classic “M” shape.
When considering bird flight, it is important to remember that air is essentially a fluid. So even though air is made of gas molecules, it flows like water. Ospreys employ a variety of flight techniques to move through this fluid—flapping, gliding, soaring, diving, hovering, and kiting. It will take the juveniles several months to master these techniques. With constant practice, the fledglings learn to combine these techniques to maneuver effectively and efficiently.
During basic powered flight, an osprey holds its wings arched at the wrists to yield maximum lift. It flaps its partially folded wings, which look like an “M”-shaped from a distance.
To soar and glide, the wings are held straight at close to right angles from the body. During gliding, the osprey flies straight, slowly losing altitude unless a current of warmer air raises it up. Because of their wing shape, ospreys can theoretically glide 10 to 13 feet while losing
only one foot of altitude in still air. During migration, actual glide ratios are in the 7 to 12 range because the birds usually travel at faster airspeeds, reducing the glide ratios. With a tailwind, a migrating osprey can realize over the ground glide ratios of 20 or better. Soaring is basically gliding at slow speeds in circles, usually in thermal updrafts.
Soaring over the lake.
Ospreys hold their wings still, crooked at the wrist, and hover above the water while looking for fish. For brief periods in certain wind conditions, they have the unusual ability to kite, float effortlessly in the breeze.
Looking at flight from a bird’s point of view, there are four main forces to consider. Weight is a force produced by gravity in the downward direction and is counteracted by producing lift.
When carrying prey, the osprey must compensate by flapping with extra force to generate additional lift.
Anything moving through air produces drag, which slows it down so there must be a forward-moving force called thrust to oppose the drag. These two pairs of forces weight and lift and drag and thrust have to roughly be in balance for a bird or plane to fly.
The forces of propulsion or thrust vs. drag and lift vs. weight on a bird in flight.
At the simplest level, bird wings achieve lift through differences in pressure of the air as it moves over and under the wing as Daniel Bernoulli's described in his principle of flight in the early 1700s. Bird wings are shaped like an airfoil where the distance from front to the back of the wing on the top is greater than the distance from the front to the back of the wing on the bottom. The same amount of air must pass over the top and underside of the wing, but the air moving over the top must move faster since it has a longer distance to travel. This gives the air over the wing less pressure than the air beneath the wing (the Bernoulli Effect). If a bird is moving fast enough, the force from the pressure difference, called the lift force, equals or exceeds the weight of the bird so it is able to fly.
The difference in length between the two sides creates a difference in air pressure between the top and bottom surface. The top of the wing has less air pressure than that below the wing, because the air is traveling at faster to complete the longer path. This dynamic generates lift that pushes the bird upward.
Air moving over an airfoil or bird wing.
The slots at the end of the ospreys’ wings reduce drag during flight and wingtip vortices "capturing" the energy in air flowing from the lower to upper wing surface at the tips. This takes advantage of prevailing wind to reduce the energy needed to fly. For example, if a flapping osprey is flying at thirty-five miles an hour, a tail wind of twenty miles per hour gives it a speed of fifty–five miles per hour.
True hovering, which is generating lift through flapping alone rather than as a product of the bird's passage through the air, demands a lot of energy and is limited to smaller birds like hummingbirds.
An osprey wind hovering, staying almost stationary above its prey to get a lock on its position before diving.
Ospreys, kestrels, terns, kingfishers, and other larger birds that we think “hover” are really not just suspended. Instead they face the headwind to “wind hover” allowing them to remain stationary relative to the ground (or water).
Another feature of the Bernoulli Principle is if a bird’s speed doubles so does its lift. If the speed triples, the lift increases by a factor of 9. This is why birds and aircraft take off into the wind to get the extra lift. With any amount of wind present the amount of lift produced increases significantly, reducing the effort necessary to become airborne.
The shape and contour of the osprey’s body is sleek to minimize air resistance. For the osprey to fly, they have to have enough forward speed to generate lift and enough thrust to sustain the lift. In flapping the wings, thrust is generated by the downward movement of the primary wing feathers. When the force of the thrust equals the resistance of drag, the osprey stays airborne.
The sleek, aerodynamic lines of the osprey, cutting through the wind.
The aerodynamic elegance of the osprey in flight is apparent when you see it head on. When gliding with their wide wings spread, they literally slice their way through the air with knifelike precision. Built to reduce drag, their gliding flight seems effortless.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
This email address is being protected from spambots. You need JavaScript enabled to view it.
For more information on bird flight, please read How Birds Fly by David Goodnow and Birds in Flight: The Art and Science of How Birds Fly by Carrol L. Henderson. Support our local economy and by locally! Both books are available at Wildbirds Unlimited at the Cornell Lab of Ornithology, 149 Sapsucker Woods Road, Ithaca.
This blog, as do many of the others, features outstanding osprey photographs by Andy Morffew, a terrific fellow osprey follower and skilled photographer, who splits his year between the Gulf coast of Florida and Hampshire, England and travelling wherever the birds take him. Look for his biography on our upcoming Contributing Artists page on Salt Point website.
#32
Getting Air
July 26, 2014
One of the many wonderful things about watching ospreys is that they are big, beautiful animals that, although they their lives out in the open, don’t seem to mind humans. Even around humans, they operate on their own timetables and not ours, according to life on osprey time.
The one o’clock feeding was a big hit—a small-mouth bass just over 10 inches. It must have come up to the surface just at the right time for Orpheus to nail it. The chicks were impatient as Ophelia doled out the food; Oya kept trying to grab the fish as her mother worked to tear it apart. As Ophelia was feeding Orion, Oya lunged in and took part of the fish to the other side of the nest. Ophelia tolerates this behavior as the chicks begin to feed themselves. Unlike the chicks last year that had a late start, these hearty chicks should have no problem learning to fly and fish in time for migration.
The skills needed for flying and hunting are innate; however perfecting these can take years. Young ospreys fly and hunt on their own, but spend considerable time observing their parents and undoubtedly learn by watching their actions. The actual maneuvers involved are learned by trial and error. In my nest watching, I see many instances that could be interpreted as teaching moments, especially during fledging. As they did last year, Ophelia and Orpheus seem to be demonstrating flight techniques around the nest for the benefit of the soon-to-be fledges. Orpheus hovers directly above the nest expertly controlling his every movement and maintaining his position. Ophelia, chirping to get the chicks’ attentions, flies in tight circles around the nest using her tail as a rudder to make a perfect soft landing.
Fledgling getting air.
When the chicks first fledge, it is evident they have much to learn about the nuances of flying, including judging distances and landing, but the huge amount they have already learned while in the nest about wing control, balance, and muscle coordination is evident. They have the ability to take to the air and go where they choose. What they do not know how to do is land safely and that can only be learned outside the nest. These nascent landing attempts are guaranteed to be awkward, often highly comical, and sometimes death-defying as the young fledges tend to approach the landings too fast or steeply and fly much too close to the ground, vegetation, buildings, or other obstacles.
According to Alan Poole, the average time for ospreys to fledge in the northeast is between 50-55 days. However, ospreys being individuals fledge when they are ready and gradually gain their independence at their own rates. Robyn, from the 2013 Salt Point nest, spent days glued to the nest edge staring down at the ground before she took her first leap into the air, while her siblings flew with the first opportune wind. Oya (50 days old), Odin (47 days old), and Orion (44 days old) are learning by imitating each other and their parents and will continue to do so until they migrate. Oya has tasted her first air and will probably take her maiden voyage sometime this week. Once Oya fledges, it will give Odin and Orion more room in the nest to practice their flapping.
After fledging, the chicks will spend weeks perfecting their flying before starting to learn to hunt. In one study, young ospreys began fishing five days after fledging, but most were not able to catch fish reliably until 20 days after fledging. At this point we call them “juveniles,” implying they are able to hunt for themselves, but their fathers will continue to bring fish to the nest for their offspring for another two weeks after fledging. This supplemental feeding provides a vital transition period before independence and insures that the young are fully capable of enduring their long solitary migrations southward.
Nest building and decoration is an ongoing fact of life in the osprey nest. The finer lining material is continually swapped for fresh algae and leaves, fallen twigs are replenished, and decorations are always coming and going at the nest. While Ophelia and Orpheus maintain a certain standard of good taste by not loading their nest with human flotsam, at least as far as I can see, other pairs go for interspecific finishing touches to their décor.
Female delivering a tee shirt to decorate her nest.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
This email address is being protected from spambots. You need JavaScript enabled to view it.
#31
Circada Song
July 25, 2014
In the early spring songbirds dominated Salt Point with their lively choruses and colorful breeding plumages. Now that their breeding season is near over, insects are sharing the center stage. Instead of the spring chorus of the birds, the summer air is filled with the buzzing and drone of insects. Song sparrows, robins, catbirds, goldfinch, and red-winged blackbirds are still ever present, but their songs do not command the attention as before. In the evenings, cicadas take center stage in midsummer.
The drone from a single annual cicada (order Homoptera) drowns out the Eastern Phoebes and Song Sparrow singing nearby in a cottonwood. It’s only during lulls that you notice how loud these insects really are. They are the sound of summer to many in the Northeast.
Size of a typical cicada.The male cicada has loud noisemakers called "tymbals" on the sides of the abdomen. Its "singing" is not the stridulation, where one structure is rubbed against another, that characterizes many other familiar sound-producing insects, such as crickets. Rather, the tymbals contract to produce a clicking sound that is amplified by using the body as a resonance chamber. Each species of cicada has its own song and is able to modulate the sound by changing the position of its abdomen. In other words, one insect can make a lot of noise: an infestation can be deafening.
Cicadas are famous for their penchant for disappearing entirely for many years, only to reappear in deafening force at regular intervals. This year happens to be an irruption year for the periodic 17-year cicadas in the Northeast and their drone is overpowering. These insects live out most of their long lives as nymphs underground, but each 17 years, they crawl out of the ground for a three-to-four-week festival of singing and mating. Afterwards, they die. Early estimates for 2014 suggest there might hatch as many as 30 billion to1 trillion cicadas in the U.S. Northeast this year. But they won't be emerging this year in Central New York. The local 17-year cicadas are on a different timetable: They came out in Central and Western New York in 2001 and won't return until 2018. They are known as “Brood VII;” this year’s more widespread batch is “Brood II.”
Periodic cicada (courtesy of National Geographic).
Cicadas are large, non-toxic, and with no physical defenses against predators. It seems intuitive that birds would feast on them during mass emergences. But recent research by Walter Koenig at the Cornell Lab of Ornithology has found that most bird populations decrease during these emergences—only populations of Yellow-billed and Black-billed cuckoos increased. Does the loudness of the cicadas’ calls temporarily drive birds out of the area?
Koenig said, “It looks like the cicadas are somehow engineering the bird populations by their cyclic life-history to be less common when emergences take place, reducing predation pressure. The mechanism behind this is obscure, but the fact remains that this provides a glimmer of an ecological explanation for why there might be 13- and 17-year cycles.”
Of the 3,000 cicada species, only some share in the disappearing act. Others are larger and called “annuals” because, although individuals have multi-year lifecycles, some adults appear every year. The dog day cicada, like the one buzzing now, emerges each year in the hotter days of July and August. Because of the predictable timing of their emergence in the “dog days” of summer, the first soundings of annual cicadas figure into folk wisdom, such as calculating the number of weeks to the first frost.
There are a few acts of nature, such as the passage of Halley’s comet, that are so rare and so dramatic as to seem like metaphors for the virtue of patience itself. Of these, the arrival of the 17-year cicadas, which wait nestled under the earth for nearly two decades, may be the noisiest. To me, the patience and perseverance exhibited by a mother osprey, incubating and raising her chicks exposed to the elements, is equally extraordinary and the most endearing.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#30
Fledgling
July 24, 2014
Just after 6 pm, as my husband walked down the Salt Point path to the osprey nest he heard my high-pitched “Yahoo!” A breeze had caught Oya just right and she had lift-off! She rose about 18 inches off the nest and held the position, fighting against invisible forces to stay aloft. After a very long five seconds, she alighted gently on the nest. Her hard work practicing her flight skills all week, and especially today, was finally paying off. Oya (48 days) had faced the wind, raised her wings, and tasted flight. Rewarding herself, she joined Odin and Orion at the fish Orpheus had just delivered. Ophelia encourages the chicks to feed themselves in the nest, but still intercedes when order is needed.
Oya’s first taste of flight, July 24, 2014, as Ophelia and a sibling look on.
First air.
The chicks this year are more advanced on this date than the chicks last year. The 2013 chicks had a later start and had to race against the clock during the entire season to become self-sufficient. Robyn and Paulie seemed prepared for migration, but the youngest, Stevie, left with only marginal fishing skills.
The 2014 chicks are developmentally right on target and all three seem equally robust. Odin and Orion mimic Oya’s flight practices whenever there is space in the nest. There is much experimenting and rehearsing to be done before that first real sustained flight. All three need to refine their all-important wing and tail motions used for steering and landing. Much jumping has to occur for them to perfect launching and landing. Every session of flapping in the changing breeze helps the chicks refine wing control and the marvelous capabilities of these appendages.
The adult-sized chicks now participate in nest guarding to some extent. In this photo, an intruder is harassing the nest. In response, Ophelia crouches and fluffs her feathers in a defensive posture and screeches. Oya and Orion join in by crying loudly.
This is a time of many changes at the nest. Ophelia is now willing to leave the chicks sitting upright in the nest when she is not there. She refrains from giving the hide signal she previously gave when leaving the nest, in order to give the chicks more time to flap their wings and practice flight. If not on the diagonal, she stays perched within eyesight of the nest in the cottonwood perch. If she were not on the nest when a threat, such as the Great Blue Heron flew past, one of her hide cries would drive the chicks to lie flat as pancakes in the nest.
Another notable change at the nest today is that Ophelia went fishing—the first time since April—and she brought a white sucker to the chicks. Like many other animal species, ospreys have a very clear division of labor and efficiency in their households. Once the couple reunites for the breeding season in the spring, the male takes over fishing for the entire family. Both Orpheus and Ophelia work on fixing up the nest, with the Ophelia in charge of the final decorating decisions. She does the bulk of the 5-week incubation and spends another 7-8 weeks tending to the chicks. They are her sole responsibility and she dutifully feeds and tends to their needs day and night. Meanwhile, Orpheus is charged with protecting and feeding his growing family and spends his time in those pursuits.
Ophelia eating part of a fish she caught before sharing it with her chicks.
Once the chicks fledge, job responsibilities shift again. Orpheus is now charge of feeding his three rowdy teenagers and he will see just how long a meal of his hard-won fish really lasts. Orpheus continues to fish fulltime and also takes charge of dolling out the fish to the fledges until they are proficient at feeding themselves. Family life and mealtimes continue to revolve around the nest until all the birds have left for migration in September. Ophelia will leave on migration first, sometime in early August. Until then, Ophelia resumes fishing, providing for the family, and getting back into flying shape for the migration The fledges spend their time mastering flight and will soon start learning to fish for themselves. Once the chicks are able to fish, they will be considered “juveniles.” The father usually leaves for migration once his offspring are self-sufficient and the chicks leave on their own time, usually individually.
Last year, because of the lateness of the nest and egg laying, the chicks needed to learn theses lessons in a great hurry. The chicks all left the same day and the father stayed in the vicinity of the nest site for almost two weeks, perhaps waiting to see if the offspring would return. The use of GPS (Global Positioning Systems) enables researchers to follow the year-round movements of
One of osprey tracker Rob Bierregaard’s juvenile outfitted with a GPPS tracking unit sticking out of its back feathers. (Courtesy of ospreytrax.com.)
numerous ospreys of different sex and age groups and has revealed many surprises. For one, first year birds, as well as 2nd and 4rd year old birds travel in all sorts of random directions for no apparent reason. Some go on what seem to be practice runs before their first real migration, others take circuitous routes that make little sense to us.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#29
Lake Ecology and Fish Movements
July 22, 2014
The day, pleasant, but overcast, began with a bluegill, about 8 inches long and wiggling. By the time Orpheus delivered it whole, the fish had stopped struggling. He quickly bit into the head to eat the lipid-rich brains before giving the rest to Ophelia and the chicks. Perching to guard his family as they eat, Orpheus surveyed the area. After the fish was consumed, the need for more was obvious, and Orpheus leapt into the air, and with just a few wing beats, he was over the lake. The shallow shelf off Salt Point extends for several hundred yards off shore. On hot days, he has to share the shelf with boaters and bathers, but during the rest of the time, it is his. Except for a kayak, today he had it all to himself.
Since osprey can only fish to a depth of three feet, they are slightly limited to where in the lake they can fish. On Cayuga Lake, ospreys nest in the shallow areas: on the north and south ends, from Union Spring to Cayuga, at the Seneca Golf Club, and at Portland Point and Salt Point Lansing. To understand the waters where the osprey hunts, Cayuga Lake can be divided into different ecological zones— littoral, limnetic, benthic, and profundal zones. Ospreys are restricted to fishing in two ecological zones in the lake: the shallow shelf along the shore or littoral zone and the mid-water limnetic zone where fish coming near the surface may be caught.
Ecological zones of a lake. (Courtesy of Lakeaccess.org.)
The littoral zone is the near shore area where sunlight penetrates all the way to the sediment and allows aquatic plants to grow. Plants rooted to the bottom and algae in the littoral zone, in addition to being a food source and a substrate for algae and invertebrates, provide a habitat for fish, frogs, turtles, snakes mudpuppies, crayfish, snails, clams, tiny crustaceans, flatworms, insect larvae, and other invertebrates. The littoral zone is very different from the open water environment and is the nursery area for many of the larger fish species. It is also the feeding grounds for many fish, especially the warm-water species.
The limnetic zone is the layer of open water where photosynthesis can occur. The light decreases the deeper you go until a depth is reached where the rate of photosynthesis becomes equal to the rate of respiration. Aquatic life is dominated by both warm and cold water fish and many of their foodstuffs: planktonic algae, zooplankton, and swimming insects.
Ecological zones of a lake. (Courtesy of Lakeaccess.org.)
Underneath the limnetic zone is the bottom layer, known as the benthic zone, which has a surface layer abundant with organisms in the sediment. Most of the organisms are invertebrates, such as Dipteran insect larvae (midges, mosquitoes, black flies), clams, snails, mussels, worms, crayfish, and other invertebrates. The productivity of this zone largely depends upon the organic content of the sediment, the amount of physical structure, and the rate of fish predation. Cayuga’s rocky bottom has a high diversity of potential habitats offering refuge from predators, substrate for attached algae on rocks, and pockets of organic "ooze" for food.
At 435 feet, Cayuga Lake is a deep lake with an area known as the profundal zone where light does not reach. This zone is inhabited by organisms that are either attached to or crawl along the sediments at the bottom of the lake. The sediments support a large population of bacteria and fungi. The decomposers break down the organic matter and release inorganic nutrients.
Fish move freely from one ecological zone in Cayuga Lake to another as they choose during the cycle of a day and during the year as they migrate to preferred habitats in search of food. The composition of these zones—the prey organisms living there and the microclimates in them—keeps changing with the seasons providing varied habitats to countless species.
Sunshine or lack thereof drives the annual temperature cycles of the lake, just like it does our land-based seasons. The lake itself also has four seasons: spring "turnover", summer stratification, fall "turnover", and the winter mixing period. The two turnover periods are relatively
Mixing or turnover of a lake. (Courtesy of Lakegeorge.org)
short, usually lasting for a few weeks to a month. Winter mixing occurs for approximately five months, and stratification approximately six months in Cayuga Lake.
The lake feels warm now because of the summer stratification, keeping the temperatures on the surface in the low 70s. The warm top layer is the epilimnion; the middle thermocline is the metalimnion, which changes depth throughout the day; and the bottom layer is the hypolimnion.
Changes in the thermocline layer during the year. (Courtesy of Cayugafisher.net)
These layers are all at different depths in the lake, and all have different temperature-dependent densities. Cold water is denser than warm water and the epilimnion generally consists of water that is not as dense as the water in the hypolimnion. A cyclical pattern of overturn occurs that is repeated from year to year as the cold dense water at the top of the lake sinks.
Beginning in spring, after the ice melts on a lake, the lake water is isothermal or generally the same temperature from the surface to the bottom. Wind allows circulation and mixing of the lake water. Surface water can be pushed to the lake bottom and bottom water can rise to the surface. This circulation pattern is very important in that it allows relatively large amounts of oxygen to reach the bottom of the lake. Otherwise, oxygen would have to reach the bottom by the relatively slow process of diffusion. The mixing of the lake water at this time of year is called spring overturn. The bottom of the lake may contain pockets of slightly warmer water, as water is most dense at 39 degrees F. The surface may be 35° with the warmer water below, as well as most of the fish community.
As spring approaches, the entire lake begins to gain heat and the water warms slightly from top to bottom. With continued warming, the lake begins to separate into distinct temperature layers. As air temperatures rise in late spring, heat from the sun begins to warm the lake. As the amount of solar radiation absorbed decreases with depth, the lake heats from the surface down. The warm water of the epilimnion is less dense than the colder water, hypolimnion, below resulting in a layer of warm water that floats over the cold water. A layer of water in the middle, called the thermocline, has rapidly changing temperatures with depth and separates the epilimnion and hypolimnion layers.
Position of the layers during spring. (Courtesy of Cayugafisher.net)
In late spring, the thermocline is shallow and sharp, allowing lake trout and other salmonoids near the surface. Orpheus was quite skilled at catching half to pound-sized lake trout while they were available to him. As time passes, the thermocline deepens and all the salmonoids in the lake follow. Excessive wind events can bring cold water back to the surface as upwelling, but in general, the trout and baitfish are in the depths.
Varying conditions lead to slight differences in water column structure and temperature. A sunny, windy spring like this year warms the hypolimnion the most, as increasing amounts of solar energy enter the lake and high winds keep it well mixed. This will also lead to a deeper than average metalimnion (which includes the thermocline). A sunny, calm spring leads to a colder lake bottom and shallower metalimnion.
During the summer the epilimnion will reach a maximum depth and stratification will be maintained for the remainder of the summer. So-called warm-water fish occupy this layer while the cold-water trout seek out the lower layers. The warm water, abundant sunlight, and nutrients
Summer layering of Cayuga Lake. (Courtesy of Cayugafisher.net)
brought up from the lake bottom during spring overturn provide an ideal environment for algae growth within the epilimnion. Algae growing in this layer tend to give the epilimnion a greenish hue. Stratification during the summer acts as a deterrent to complete lake mixing. Wind circulates the surface water, but the warm water of the epilimnion is unable to drive through the cold, dense water of the hypolimnion. As a result, the water is only mixed in the epilimnion.
Without mixing to provide dissolved oxygen, the lake bottom, lacking enough light for photosynthesis to occur, tends to have a very limited supply of oxygen during the summer. Respiration by animals and bacteria can deplete the dissolved oxygen at the bottom of the lake.
Changing positions of the layers during late summer. (Courtesy of Cayugafisher.net)
As autumn approaches and temperatures decrease, the epilimnion begins to decrease in depth. Eventually the epilimnion gets so shallow that it can no longer be maintained as a separate layer and the lake loses its stratification. Thus, as in the spring, the lake water in the autumn has generally uniform temperatures (about 39.2° F in late autumn), and wind can once again thoroughly mix the lake water. In addition, surface water, which is in direct contact with the cold air, gets cooled faster than the water below. This cold, dense water sinks and further helps to mix the lake, and once more oxygen and nutrients are replenished throughout the lake. This process is called autumn overturn.
Layering during the autumn after overturn. (Courtesy of Cayugafisher.net)
As winter approaches, the surface water is eventually cooled below 39°F. At this point, the water no longer sinks. The water molecules begin to align themselves solidify. As water temperatures at the surface reach 32°F, ice begins to cover the surface of the lake. During the winter, ice cover prevents wind from mixing the lake water. Again, stratification can occur. A layer of low density water colder than 39°F, but warmer than 32°F, forms just under the ice. Below this water, the remainder of the lake water is usually near 39°F. At this point, a lake is said to be in winter stagnation. The lake continues to cool into winter, reaching its coldest temperatures in February and early March. As spring approaches, the seasonal cycle begins again.
The lake warms from late March until September and loses heat the rest of the year. There are year-to-year variations mostly due to weather patterns, but in general, the lake begins to gain heat energy around the spring equinox, and lose heat at the fall equinox. There are also yearly variations in the annual heat budget. That is, one year it may gain more than it loses, or even for several years in a row. This can cause slight variations in the average yearly lake temperature, which used to average out in the long run. With global warming, there will undoubtedly be changes in our waters as the average lake temperature eventually starts to increase.
Weather conditions during the spring are critical for determining the annual heat budget. Any excess heat, above the annual average, is stored in the hypolimnion, the cold deep layer of water in the lake. Varying conditions lead to slight differences in water column structure and temperature. A sunny, windy spring will warm the hypolimnion the most, as increasing amounts of solar energy enter the lake and high winds keep it well mixed. This will also lead to a deeper than average metalimnion (which includes the thermocline). A sunny, calm spring results in a colder lake bottom and shallower metalimnion. Eventually the density gradient (due to water temperature difference) becomes too great for the wind to overcome, and the lake becomes fully stratified and remains so until fall.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
This email address is being protected from spambots. You need JavaScript enabled to view it.
#28
Appetites
July 21, 2014
It’s a cloudy day to start, with air and water temperatures in the low 70s, and a sky full of cumulus clouds. It is a perfect day for the chicks to move around, dry off, and stretch out. It is also looks like a great day for fishing with only a slight breeze and few waves; at times, the water seems still, just ripe for Orpheus’ fishing. Lately, yellow perch has replaced trout on the menu, but Orpheus surprised the gang just after 8 in the morning with a foot-long smallmouth bass, a nice way to start the day.
Parent feeding chick, although by five weeks of age the chicks can feed themselves. (Courtesy of Andy Morffew).
The fare for the rest of the day consisted mostly of yellow perch, interspersed with the occasional small bullhead and sucker as a palate teaser. Not that a diet of yellow perch is anything to sneeze at. But since they are so boney, Orpheus has to catch more to satisfy the needs of his ravenous family. Even though the air temperatures have cooled, the water remains much warmer and cold-water species like trout remain, for the most part, out of Orpheus’ grasp.
Pan fish for lunch. (Courtesy of Andy Morffew).
Of all the pan fish, perch and bass are by far the meatiest and most satisfying to the osprey. Bluegills and sunfish, in comparison, yield precious little for the effort of catching them. The chicks sometimes look as though they were choking as they work to cough up inedible pieces of fish, but rarely spit out anything afterwards. Bullheads, on the other hand, are very fleshy and except for the bones and spines, make an excellent meal.
A fleshy bullhead for dinner. (Courtesy of Andy Morffew).
A break in the clouds came after midday and the trio took this opportunity to stretch their wings, dry out, and preen. The sun also brings out biting insects, against which the flightless chicks are rather helpless, although they can scratch and nibble at them. Mosquitoes are especially annoying in the evenings. Whenever the sun peaks out from the clouds the mombrella pops for shade. She moves with the sun: In the mornings she faces the lake, slowly rotating around to face the hills in late afternoon.
A breeze off the south end of the lake eventually clears the sky leaving a gigantic ring of fluffy cumulus clouds around the lakeshore. Ophelia, giving the chicks some needed room, jumps into the wind and demonstrates her aerial prowess. Orpheus soon joins her and the two put on a breathtaking aerial tango around the nest box, mirroring each other’s every movement, matching circles with circle within a few feet of each other in the sky. They fly in parallel along the lake, looping and diving as one, in a seemingly well-practiced choreography. It was as if they were giving an aerial exhibition for the chicks, showing them the glorious things wings enable them to do.
Flight is something humans can only fantasize about. Chilean poet and Nobel Laurite Pablo Neruda (1904 to 1973) captured the essence of birds in flight in Art of Birds. He gives words to the imagination, enabling us to sense the unknowable—the wind under our sails. There were no ospreys in Peru for Neruda to enjoy and write about, but his works on other high-fliers are evocative of them.
After the flight exhibition, Orpheus leaves to hunt, deliberate as Neruda’s kestrel in the excerpt below, hovering above its prey before making the sudden strike:
from American Kestrel
Falco sparverius
High noon opened up:
the sun in the center, crowned.
The earth awaited indecisively
some movement in the sky
and everyone remained
indecipherably still.
At that slender second
the hawk hammered its flight,
cut loose from the firmament,
and swooped like a sudden shiver.
It is daunting to imagine, but in a very short time the Oya, Odin, and Orion will soon master the art and science of flight. After seeing their first tentative hops, it is hard to envisage them swooping ”like a sudden shiver,” but they soon will. Visitors to the Salt Point root for the chicks’ as they the flap, prance, and jump in the air for all they are worth.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#27
Flight School Begins
July 20, 2014
Preening and exercising are top priorities for Oya (44 days old), Odie (41 days old), and Orion (38 days old) as they approach fledging. When not jumping, flapping, or doing both from one side of the nest to the other and back, the chicks conscientiously preen their feathers in preparation for flight. They methodically rub their bills and heads against their preen (uropygial) gland opening and distribute the accumulated waxy preen oil over their body and wing feathers, and on the skin of their feet and legs. The tail areas are usually preened using the beak only. Scratching near the ears and other hard-to-get places further spreads the preen oil and removes parasites their beaks cannot not reach.
Visitors are amazed when the chicks climb atop the nest to unfurl and flap their wings—they’re the size of their parents! It’s hard to believe, but sometime in the next two weeks, usually around days 50-55, these enormous babies will transform and fledge, getting their first taste of what it’s really like to be a true osprey. The trio have much work to do and skills to learn first—manicuring feathers, mastering balance, building flight muscles, developing coordination, controlling their wings, and, perhaps most vital of all, learning how to land. Each on its own time, the chicks will confront the wind, jump into it with wings spread full, and leave the nest.
Once they get their first inkling of the wind beneath their wings—their first taste of freedom—there will be no turning back. From that first flight day on, they will have an extraordinary skill, one humans have coveted for ages.
“Once you have tasted flight, you will forever walk the earth
with your eyes turned skyward, for there you have been,
and there you will always long to return.”
― Leonardo da Vinci
Humans have always dreamt of flying. Leonardo da Vinci, the quintessential Renaissance man, was one of the first European’s to make a concerted study of aviation. Leonardo designed a multitude of mechanical devices, including parachutes, by studying the structure and flight of birds and bats. He seemed truly excited by the possibility of people soaring through the skies like birds and in 1485, he invented the "ornithopter.”
Sketch of ornithopter by da Vinci (courtesy of <http://science.howstuffworks.com/transport/-flight/classic/ten-bungled-flight-attempt2.htm>
Leonardo da Vinci’s flying machine (see above) had a wingspan of over 33 feet, and the frame was to be made of pine covered in raw silk to create a light but sturdy membrane. The pilot would lie face down in the center of the invention on a board. To power the wings, the pilot would pedal a crank connected to a rod-and-pulley system. The machine also had a hand crank for increased energy output, and a headpiece for steering. As the busy pilot spins cranks with his hands and feet, the wings of the machine flap. The inspiration of nature in the invention is apparent in the way the wings were designed to twist as they flapped. Unfortunately, as da Vinci realized, while the flying machine may have flown once it was in the air, a person could never have created enough power to get the device off the ground.
There is no evidence that he actually attempted to build such a device, although the image he presented was a powerful one. The notion of a human-powered mechanical flight device, patterned after birds or bats, recurred again and again over the next four centuries.
Balloonist made the next inroads into the field of aviation. In 1802 André-Jacques Garnerin and Edward Hawke Locker make a 17-mile balloon flight from, London, England, in just over 15 minutes. The following year he flew 245 miles from Paris to Clausen, Germany. But perhaps Garnerin was best known for scandalously taking a single young female aboard one of his controversial balloon flights.
Sir George Cayley is considered the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight. His first aerial device, built in 1796, was a model helicopter with contra-rotating propellers. In 1804 Cayley designed and built a model monoplane glider of strikingly modern appearance. The model featured an adjustable cruciform tail, a kite-shaped wing mounted at a high angle of incidence, and a moveable weight to alter the center of gravity. It was probably the first gliding device to make significant flights.
The following year Cayley discovered that dihedral (wings set lower at their center and higher at their outer ends, like on a turkey vulture) improved lateral stability. He continued his research using models and by 1807 had come to understand that a curved lifting surface would generate more lift than a flat surface of equal area. Cayley’s 1810 groundbreaking treatise On Aerial Navigation stated that lift, propulsion, and control were the three requisite elements to successful flight.
By 1816 Cayley had turned his attention to lighter-than-air machines and designed a streamlined airship with a semi-rigid structure. In 1837 Cayley designed the vehicle to be powered by a steam engine. Switching to lighter vehicles, in 1849 Cayley built a large gliding machine, and tested the device with a 10-year old boy aboard. The gliding machine carried the boy aloft on at least one short flight.
Sir George Cayley 1852 gliding machine (Courtesy of Flyingmachines.org)
In1853, Cayley built an even larger gliding machine and had his coachman aboard when he tested the device that same year. An oft-repeated story holds that after the short flight Cayley's coachman stated that he had been hired to drive a coach not to fly a glider. Sir George Cayley was the single most important aerial researcher and theoretician of his time and inspired the next wave of aeronauticists.
Next came the du Temple Monoplane—a large aeroplane made of aluminum, built in France, by naval officer Félix du Temple in 1874. It had a wingspan of 43 feet and weighed only 180 pounds without the pilot. The aircraft used a very compact, high-speed circulation steam engine. Several trials were made with the aircraft, and it is generally recognized that it achieved lift-off. It staggered briefly into the air from a combination of its own power and running down an inclined ramp, glided for a short time, and returned safely to the ground, making it the first successful powered flight in history though not the first self-powered one.
Next in the flight Hall of Fame was Clement Ader’s Eole or Avion, an early steam-powered aircraft developed in 1890. It was the first piloted aeroplane to take off under its own power, for a brief uncontrolled hop.
The work of the Lilienthal brothers, Otto and Gustav (1849-1933), with gliders in Germany was, arguably the most important aerial effort prior to that of Orville and Wilbur Wright. Otto Lilienthal's
Lilienthal in flight 1895. (Courtesy of Carroll Gray Flying Machines)
over 2,000 flights gliding up to 230 meters demonstrated beyond question that unpowered human flight was possible, and that total control of an aerial device while aloft was within reach.
Controlled, powered flight had seemed impossible until Orville Wright took off on December 17, 1903, near Kitty Hawk, North Carolina. The key to the Wright Brother's success was that their engineering had gone beyond the trial and error methods of their contemporaries and was based on four years of true scientific experimentation. The Wright Brothers were the first to design their propellers as an aerofoil, like a bird’s wing. What they achieved changed our world forever.
The desire to fly is an idea handed down to us by our ancestors who, in their grueling travels across trackless lands in prehistoric times, looked enviously on the birds soaring freely through space, at full speed, above all obstacles, on the infinite highway of the air.
—Wilbur Wright
Orville Wright near Kitty Hawk, NC. “First in Flight.” (Courtesy of wrightbrothers.info)
Human’s quest to fly continues and we’ve become interlopers of the skies and heavens with our vast array of aircraft and spacecraft. In one hour alone this morning, two Chinook transport helicopters, a commercial airliner, a private jet, and a biplane flew over the platform at Salt Point. Ophelia seemed oblivious, but the chicks paid great attention to these strange crafts.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#26
Big Babies
July 18, 2014
Looking up at the osprey nest this morning, I was amazed at the number of changes in just five short weeks. The Salt Point chicks have gone from being tiny, helpless reptilian creatures to really big, adult-sized birds—yet still awkward nearly helpless, and totally dependent on their parents for food, shelter, and protection. Oya (42 days old), Odin (39 days old), and Orion (36 days old) are nearly fully feathered and eat as much as the adults. The chicks are eating machines and their mantra is “Feed Me!” Orpheus has little time for loafing now; he is busier than ever fishing for five adult-sized appetites, spending probably a minimum of 3 and a half hours a day in excellent weather and much more time on off days.
Feed Me! Big baby Orion (36 days), mother Ophelia, and Odin (39 days) getting shade.
At five weeks old, the chicks spend their waking hours waiting for fish and readying for their next big adventure sometime in the next two weeks—flight! When not stretching, preening, or flapping their unruly wings, they often do vigorous jumping jacks from side to side while flapping their wings, stopping only to pant and cool off. These flapping jumping-jacks sessions, dubbed “flappersizing” by osprey cam viewers, are crucial to mastering balance, gaining control and coordination of their cumbersome wings, and developing strength in their flight muscles.
Oya at 42 days flappersizing, but going nowhere.
“Flappersizing” takes lots of energy and the chick trio develops healthy appetites. Orpheus needs to catch the equivalent of about two and a half to three fish about 10-12 inch long for each member of his family and up to three and a half fish for himself, adding up to 13-16 fish each day, rain or shine.
Most ospreys catch fish weighing between one-third and two-thirds of a pound (around a foot long), although Orpheus has brought home many lake trout, bass, pike, and carp all tipping 2 pounds. In general, adult ospreys need 290 kcal/day and young at time of fledging (50-55 days old) need 255 kcal/day. Because he is fishing for five, Orpheus must eat more than 290 kcal, and has a daily energy expenditure of about 320 kcal/day.
Aside from water, fish flesh consists almost entirely of proteins and lipids, with lipids providing more than twice the metabolizable energy (9.5 kcal/g) available in protein (4.2 kcal/g). Orpheus usually eats the fish brains for these high-energy lipids before sharing the remaining fish with his family. Different fish species have different lipid and protein contents as well as different edible portions, and thus provide different energetic values to the osprey. Bullheads, bass, and trout have far more meat on them than do the boney sunfish, perches, and other pan fish. The older the chicks get with their adult appetites, the more Orpheus must fish.
Mombrella and the chicks look on as Orpheus flies off for another fish.
Once the chicks get their full compliment of contour feathers, the small feathers that cover the body, wings, and tail to fill in the spaces, the trio will become aerodynamically ready to challenge the skies—well, almost. At 42 days of age, all of Oya’s contour feathers have just grown in and she is ready for more serious flight lessons. When room permits, her jumping jacks will eventually gain her some altitude, but she also has to strengthen her legs and wings more before she gets some serious air and takes her maiden voyage.
There is no data on the number of feathers an adult osprey has, but in general, the larger the bird, the more the feathers it has. A hummingbird, for example, has about 950 feathers covering its tiny body, while a swan has about 25,000 feathers. No wonder it takes so long to care for each feather when the birds groom.
L-R: orange-eyed chicks Odin, Oya, and Orion (under Ophelia, adults have yellow eyes) are now adult-sized and take up lots of nest space.
When Oya and Odin open their wings at the same time chaos ensues in the nest. Refolding one’s wings sounds easier than it looks, at least from a chick’s viewpoint. Orion squeezes in his flapping time whenever his bigger siblings are not hogging the nest space. Preening is essential after such commotion to put everything back in place and to do a good job takes more time than the chicks seem to have patience for. Instead of looking sleek and neatly coiffed when done, the chicks often have feathers going every which way, requiring more effort to smooth them all down. Oya is just now getting the hang of long preening sessions to do the job correctly. On numerous occasions, when the gang is tending to its needs, Ophelia’s gotten slapped in the face by an errant wing or two, but takes it in stride like the good mother she is.
Odin spreading his wings last week at age 33-days. They are more filled out and darker now.
Even though they are days away from flight, Oya, Odin, and Orion continue to act like chicks as they sleep huddled together in the nest with their heads tucked. Since they cannot fly, this posture is their main line of defense—camouflage—and it still works beautifully with their speckled plumage. Orion is usually found under his mother’s wing, seeking shade. He knows when he’s got a good thing. Oya and Odin are more independent and spend more time at their mother’s side, peering out at the world.
When not acting as a mombrella or feeding the crew, Ophelia is starting to spend more time off the nest, mostly on the diagonal perch or in short flights around the nest. She tries to give the chicks plenty of space, but even so, they tend to pile up in each other’s way, instead of spreading out in the nest box. In their world, two objects can occupy the same space in the same time.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#25
Big Foot
July 14, 2014
Osprey: Fish Hunter
patrolling the sky
scanning for fish in water
osprey fish hunter
flutter and hover
seeing fish shadows below
preparing to dive
swift steep plunging dive
plummeting down through the air
hunger is appeased*
Like all osprey, Orpheus is uniquely adapted for fishing. His powerful, hooked bill and claws (or talons) are perfect for cutting and tearing slippery fish. The beak and talons grow continuously, much as our fingernails do, to compensate for the wear and tear of fishing. These lethal talons close like a trap, snapping shut within two hundredths of a second.
Ospreys can change the arrange of their toes to have three in front with one in back or two both back and front.
Perhaps the most notable adaptation to help Orpheus grasp slippery fish are ospreys’ unique feet, which have barbed scales or spicules on the underside of each of the four long toes. His unusual fourth toe is reversible and can either be at the front of the foot or moved to the back for a two toe forward, two toe back formation for carrying fish. No matter which way a fish thrashes,
the osprey’s powerful talons and raspy toes can hold it fast. After making a catch and emerging from the water, Orpheus thrusts the foot holding the fish’s head forward in torpedo fashion, taking advantage of the natural aerodynamic shape of the fish to reduce drag and make it easier to carry his catch. To further lighten his load, Orpehus gives a quick “dog shake,” before flying to the nest to the welcoming chirps of Ophelia and the gang.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
*http://naturetales.blogspot.ca/2008/06/osprey-fish-hunter.html
#24
The Storm
July 8, 2014
(My apologies for the late submission, due to the joyful chaos of my visiting young grandsons.)
Tuesday night’s storm showed the uninitiated just how ferocious Cayuga Lake can be, especially in a tempest. The promise of a gorgeous sunset fizzled that evening with the onset of thunderheads stacking up across the sky and a curtain of rain slowly threatening Salt Point. I bid the point adieu as the first raindrops fell. By the time I reached home (a few miles south as the osprey flies), it had become a full-fledged 26 mph fury. We scrambled to move the important things, like our grandsons and laptops, inside just as the storm let loose. A steady downpour, rolling rumbles of thunder, and a flashy lightening show overhead at first seemed like a welcomed relief after a string of long humid hot ones. Nonetheless, the charge of excitement quickly faded as the waves turned into 3-foot white-caps, branches started crashing about, and trees were splitting in half and toppled over as the winds gusted to over 40 mph.
Then the lights went out. There was still ample ambient light to see indoors, but our half-cooked dinner came to a screeching halt as we set aside the partially–cooked pasta and switched to grilling. Sometime after midnight, our electrical service returned, but Lansing Station may be without power until Saturday July 12. Officially a tornado hit the area damaging trees, buildings, and automobiles from Ithaca to Lansing Station and beyond.
I checked on the osprey early Wednesday morning, July 9, to make sure all in the nest were fine. Salt Point was waterlogged and puddled, with fallen debris and limbs strewn all about. The wind spirit Oya must have been twirling her skirts, dancing in delight on Tuesday night, to make tornado-strength winds. All three chicks popped their heads up for some of the brown bullhead Orpheus delivered at about 7:38 am, letting us know all was well at the nest.
The rest of the morning the youngsters spent much of their time stretching, panting, preening, and getting tangled up in each other’s wings. Oya, Odin, and Orion are nearly adult size at 31, 28, and 25 days old. All three are busy moving about the nest and practicing flapping as they build up their flight muscles. Their activities decrease as the day gets too hot —Today, July 8, it’s already muggy and 80°F by 8 am. The chicks are still camouflaged, but now have a tawny “salt and pepper” speckling all over, clean white necks, and more predominant bandit masks. When open, their fiery orange eyes give their presence away.
The largest chick, Oya, on the left of her mother, Ophelia.
As in many families, whatever the oldest sibling does the younger ones mimic and the nest seems to shrink daily as the chicks complete their growth spurts. While one chick exercising its wings takes up lots of space, two chicks stretching and flapping turns the nest into a comedy of errors. When all three get the same notion at once, it becomes a free-for-all with feathers flying, awkward wings flapping, and limbs tangling with each other.
Now is when the chicks are truly cute and easy to see with binoculars. The best times to look for them are when they are getting fed or when they pop their heads up from underneath their mother’s sheltering wings in the cooler parts of the day. They no longer look like a jumble of prehistoric species, but are identifiable as raptors, and as ospreys at that! Granted they are still in the comical wobbly, bobble-head phase and their wings are a rag-tag mix of feathers in different stages of growth, they now show the beginning signs of the elegance particular to ospreys.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#23
Fireworks
July 3 and 4, 2014
Ophelia in a typical defensive posture with the chicks hunkering down below her.
On July 3, 2014, the chicks are 28, 25, and 22 days old and bouncing around the nest, stretching and flapping their long ungainly wings as they vie for the best shade and choicest morsels of fish. Oya, Odin, and Orion are at the bobble-head doll stage, their large heads seemingly connected to their bodies by springs. Their curiosity overwhelms them as they look out over the nest and wobble their heads from side to side as if to get a better look.
Ophelia with two of her three panting chicks.
Their feathers are a mixed pattern of dark chocolate, tawny, chestnut brown, black, and white, blending perfectly with their surroundings. These feathers are all in different stages of development. Their primary feathers are coming in at different rates and their tail feathers are starting to emerge. One chick I saw this morning had a tail about an inch long.
As mentioned in an earlier blog, osprey chicks go through an accelerated growth spurt from ten to thirty days after hatching, for males, and ten to thirty-five days for females. During these growth phases, female chicks get bigger and gain more weight than do male chicks. Since male ospreys have less weight to gain, they may mature faster than females and sometimes start flying and fishing on their own. Oya, Odin, and Orion are changing daily in the middle of this exponential growth phase. In a few days they will be entering the “super fast” growth stage and will seem to grow before your eyes!
Sigmoidal growth curve showing osprey chicks’ accelerated weight gain as they approach adult size. (Courtesy of University of Montana Osprey Project.)
If danger is present, one cry from Ophelia is enough to send the chicks low into the nest where they stay still and camouflaged. Every time an intruding osprey comes near, the chicks get a fire drill in hunkering down. As of today Oya, Odin, and Orion are well-schooled in what to do in the event of a raid by a gull, heron, eagle, or any other large flying creature—hunker down silent and motionless until mother arrives.
Pre-Show Jitters
The community fireworks will be held tonight on the northeastern lawn of Salt Point about 300 yards from the osprey nest, weather permitting. The fireworks used to be held closer to the osprey nest, but the town relocated them last summer to protect the birds. Little is known, however, about the impact of so much noise and flashes of light on birds and other wildlife in the area, and I have concerns for the ospreys’ safety. Will the adults flee the nest in a panic? Will the excited little ones fall out of the nest? Unfortunately, the Town of Lansing cites safety reasons for why I cannot stay on Salt Point during the fireworks to study the osprey reactions. It is a shame because there is little in the scientific literature on the effects of these explosions and noise on nesting osprey. The bulk of information about osprey reactions is anecdotal. Nonetheless, safety concerns prevail.
Researchers studying the effects of noise pollution on wildlife have found reactions predictably vary with the frequency and intensity of sound, species of animals, their stage of life, ecological niches, population density, and physical status. Reports cited by Singh Swatantra et al. in Pharma Science Monitor (volume 5(2), Apr-Jun 2014, pp. 169-175) indicate that noise pollution in the form of fireworks create strong fear reactions in a vast number of wild animal species worldwide. Some wavelengths may cause physiological damage to the animal’s auditory and/or and central nervous system. Given time, many species can adapt to loud noise but not to periodic blasts, such as fireworks.
The University of Amsterdam in the Netherlands uses weather radar to track birds’ reactions to New Year’s Eve fireworks celebrations. On their website <http://horizon.science.uva.nl/fireworks/index.2012.en.html> thousands of water birds can be seen fleeing during displays. The birds most affected are ducks and geese overwintering at quiet wetlands. However, direct comparison to ospreys is limited.
After reading the current methods used by airports and other industrial facilities to drive away birds, fireworks seem like the ideal method, making me all the more concerned about tonight’s festivities.
It is hoped the osprey chicks will hunker down deep in the nest during the firework explosions as the chicks did last year. What little information there is in the literature about birds’ reactions to gunfire and explosions predicts that the parents will probably spend the time in the trees nearby. However, town staff said the parents stayed on the nest last year during the festivities. I interpreted this as nest guarding and a very gutsy thing to do in their first year as parents in the face of unknown danger. Explosions and gunfire scare many animal species, birds included, but this pair did not flee. Protective parental instincts won over their fear and, hopefully, they will again tonight. After this hot and stormy day, Ophelia is already frazzled and doesn’t need the additional stress this fireworks display will bring.
The Aftermath, July 4, 2014—Are the Chicks OK?
I dreaded going out to Salt Point last year on July 4 as I did today to look for unfortunate chicks under the pole. Stalling until 8:30 am and bringing my husband along for moral support, we went to Salt Point only to find friends Robert and Oya Rieger doing the same. With much relief, we
Happy Fourth of July, wee ones, you made it!
saw all three chicks pop up. What a relief to know the osprey family survived another evening of pyrotechnic Independence Day celebration.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#22
Hunters and Warrior Poets
July 1, 2014
Ophelia, with whitewash on her feathers, feeds her little trio of “Os.”
This year’s chicks have finally shown their heads this weekend, visible above their mother’s skirts. They are named for warriors and hunters— Oya, Odin, and Orion—who share the poetic nature of the original Orpheus. The eldest female chick is Oya, a Turkish female name meaning lace, and a Yoruba goddess and warrior-spirit of the wind, hurricanes, tornadoes, lightning, fertility, fire, and magic, which are born from her whirling skirts as she dances for delight. Her winds may bring destruction, but they also bring the spirit of change, transition, creation, and new growth.
The eldest male chick is Odin, the Norse and Germanic wise king of the gods, the God of war, and bringer of victory. He was also associated with wisdom, poetry, prophecy, Shamanism, and magic. If the chick turns out to be a she, then her name will be Odie. The youngest chick will be named Orion, after the great hunter and my favorite constellation. Orion's seven brightest stars form a distinctive hourglass-shaped asterism, or pattern, in the night sky. Four stars—Rigel, Betelgeuse, Bellatrix, and Saiph—form a large roughly rectangular shape, in the center of which lie the three stars of Orion's Belt—Alnitak, Alnilam, and Mintaka. Descending from the 'belt' is a smaller line of three stars (the middle of which is in fact not a star but the Orion Nebula), known as the hunter's 'sword.'
Constellation Orion
July 1, 2014 soars into the 90s by noon with high humidity and thunderstorms threatening. The only saving grace to this muggy day is the faint breeze on the point. Ophelia offers the only shade and Oya, Odin, and Orion (about 26, 23, and 20 days old) hide from the heat under their mother’s spread wings and spend their time panting to cool off. In the cooler early mornings, the chicks practice flapping their little wings and scratch and preen their itchy new feathers. But as the morning warms, the chicks tumble over one another as they vie for a position under their mother’s wings, who will stand shading them until sunset, if necessary.
One of the chick’s practices flapping while Ophelia feeds another.
The hot sun does keep the nest bacteria, mold, and parasites to a minimum and dries out Ophelia’s feathers. Too much rain can actually waterlog an osprey, thereby hampering flight.
Ophelia’s instincts and physical endurance to shade her young as a Mombrella all day long fascinates me. The maternal drive is hugely powerful across the animal kingdom and is certainly not lacking in ospreys. Ever since she arrived in early April, Ophelia has readied her nest and dedicated herself to tending her offspring. She is single-minded and devoted with one mission—raising a healthy brood—and it requires great perseverance, and steady cooperation from her mate.
Ophelia or “Mombrella” shading the chicks with her body. Two chicks are below her out of view.
Never have the lessons of living simply as ospreys do been more important than now that the “dog days” of summer are starting. Between the hot sun and the frequent thunderstorms, the weather brings out the philosopher in a person. Learning to enjoy being still, listening to the birds, living slowly, spending the day watching the osprey family gives one pause. There is no better role model for dedication, patience, and endurance than a mother osprey. The fact that she must beg food is not reflection on her character. She has had to give up her independence to raise her chicks and is at the mercy of Orpheus and when he brings home fish—On Osprey Time. Ophelia’s only recourse when the chicks chirp loudly with hunger is to let Orpheus know by begging—Cheeep! Cheeep! Cheeep!
The nest is full of hungry, thirsty, hot birds waiting for their fish to arrive. Apparently frazzled, Ophelia uttered her aggravated ick-ick-ick! call after a long series of begging cries— Cheeep! Cheeep! Cheeep! Ophelia never leaves the nestlings unguarded, and flew around the nest platform twice, making tight circles and crying out loudly before landing. Orpheus came at last, landed in the nest, but sought shade in the shade of a cottonwood about 35 feet away, when Ophelia did an unprecedented move. Ophelia left the nest with Orpheus guarding from the tree and made a slow dive for the lake and dragged herself through the cool water, before returning to the chicks.
Brown Bullheads (Ameiurus nebulosus) sensing the environment with its barbels.
Orpheus finally went fishing at 4:35 pm and brought back a small 12-inch brown bullhead.* Again, in an unusual move, she devoured part of the fish first before feeding the chicks. Normally, she eats after the chicks, but she may have been so dehydrated that she needed sustenance before she could attend to her nestlings. As soon as the fish was done, she chirped to her mate for more. Orpheus returned twenty minutes later with another juicy bullhead about 14 inches long and gave it to Ophelia. After the chicks ate their fill and stuffed their crops, they fell in a lump to sleep. The parent finished the bullhead and everything was quiet again at the nest.
The Brown Bullheads (Ameiurus nebulosus) that Orpheus catches average 8-14 inches in length and can weigh up to two pounds. They are easy for the Osprey to eat because of their smooth, scaleless skin. Members of the catfish family, they have whiskers called barbels on their chin and sharp spines on their pectoral (front) and dorsal (top) fins. These spines are used for defense from predators, and can easily puncture skin. Bullheads are bottom feeders, using their barbels to feel and locate food such as dragonfly larvae, worms, tadpoles, fish eggs, algae, and other smaller bottom-feeding fish. They are plentiful in both Salmon Creek and Cayuga Lake. On spring evenings rising water temperatures, warm rain, and seasonal runoff stimulate bullheads to gather in the shallows and begin feeding aggressively—a behavior that becomes more pronounced at night. Bullheads are a main staple during this warm weather.
Typical brown bullhead with a long anal fin and spinney pectoral fin.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#21
Birds & Dinosaurs
June 25, 2014
On June 25, the chicks are 18 and 15 days old and visibly active during feedings. When not under the shade of Ophelia’s wings, the chicks exercise their wings, although in hot weather they keep movements to a minimum. The chicks preen or groom their feathers frequently to help their new feathers immerge from their waxy casings. Getting feathers is probably a rather itchy process, much like growing a beard, and preening helps work the feathers out, lines them up, and spreads the water-proofing oil secreted by their uropygial gland. Once their feathers are out the chicks will spend a lot of pushing, brushing, and running their bills through them to keep them in good shape and prepare them for flight. This is exhausting work and the chicks still spend much time sleeping.
I’d like to say the chicks are adorable, but in truth they are anything but. They still look like little dinosaurs—the raptors in Michael Crichton’s Jurassic Park—with prehistoric-looking deep orange eyes, enormous beaks, and feather pins sticking out all over. It’s clear that not all dinosaurs went extinct 65 million years ago at the end of the Cretaceous Period. One group survived, and we see their descendants every day—birds. Paleontologists recognized this link over 125 years ago, and have been investigating it ever since. Discoveries have included shared skeletal features like hollow bones and hips that allow walking upright, and fossils of feathers and nesting grounds. New finds continue to fill in the bird family tree and shed light on ancient dinosaur behavior.
Chick with pin feathers emerging from feather tracts.
The extinction of non-avian dinosaurs except birds at the end of the Cretaceous has intrigued paleontologists for more than a century. One theory is that an asteroid impact 65 million years ago off the coast of Mexico generated massive tsunamis, with impact debris cutting off sunlight for months, stopping photosynthesis and causing freezing temperatures. Chemical reactions in the atmosphere caused acid rain and long-term global warming, all of which extinguished non-avian dinosaurs. However, at the same time, massive lava flows erupted across what is now southwest India. The eruptions probably caused many of the same effects as the asteroid impact. Although most scientists believe that the impact was the final blow for non-avian dinosaurs, both events could well have played a role.
Most paleontologists have accepted the idea that birds are living dinosaurs for some time. But the discovery of Bambiraptorhas led to some intriguing new ideas about the strong links between birds and dinosaurs. Bambiraptor was probably covered in feathers and its skeleton was almost identical to that of a modern bird.
Model of Bambiraptor (courtesy of www.triunecommunications.com)
Bambiraptor belongs to the group of dinosaurs called dromaeosaurs, which are very closely related to modern birds. Dromaeosaurs had feathers and other features like hollow bones that are used in flight. But these dinosaurs could not fly because their arms were too short to function as wings. Features like feathers and hollow bones evolved first in dinosaurs that lived on the ground or climbed trees. These traits were only later used for flight. Scientists now think that modern birds are very closely related to the family of dinosaurs known as dromaeosaurs, which includes Bambiraptor.
A modern description of a Roadrunner is very similar to Bambiraptor: it has a S-shaped neck, a pubis bone in the hip points backward, a V-shaped wishbone, folding arms, and three primary toes on the feet.
Roadrunner (courtesy of Chicago Zoological Society)
In this hot weather, the nestlings move around more in the cooler hours than during the heat of the day. They pant along with the adults to cool off and shelter in the shade of their parents’ wings. The chicks do not drink water yet and must replenish their fluids from eating fish. During scorching summer heat waves, it is crucial for Orpheus to keep meal deliveries regular and frequent.
In the next week, when the chicks are between 20-25 days old, their developing remiges or flight feathers—the primaries, secondaries, and the rectrices—begin to come out of their protective sheaths. Look for the emerging feathers poking out along the feather tracts.
Getting feathers is an uncomfortable, itchy, and exhausting process. The young chicks scratch and preen as best they can frequently to help their new feathers immerge from their waxy casings. They flap their wings and tumble over one another as they vie for a position under Ophelia’s skirts. With partially spread wings, she keeps them shaded the best she can and they hunker down into little mounds. Now that it is near sundown, the chicks do not need covering and the air is thankfully getting cooler.
Ophelia as a “Mombrella” shading the chicks under her skirts.
Also between the ages of 20-35 days old, female chicks, which are heavier as adults, gain more weight than do males. Male ospreys, since they have less weight to gain, may actually mature faster than females. Hence, juvenile females take longer to start fishing on their own.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#20
Ospreys Overhead
June 22, 2014
It can sometimes be tricky identifying birds in flight. Learning the osprey’s key field marks is the best way to be able to confidently identify a soaring osprey. The only other birds that soar with bent wings are gulls and they are much smaller. The only other birds as big as ospreys are eagles and turkey vultures, neither of which fly with bent wings, making the elimination process easy.
IDENTIFYING OSPREY FLYING OVERHEAD
• Flies with bend in wings or an “M” shape.
• Eagle sized; clean white body.
• Dark chocolate brown wings.
• Black wrist or carpal marks.
CHARACTERISTIC OSPREY SILHOUETTE IN FLIGHT
Compare the overhead silhouettes and wing patterns in flight to differentiate turkey vultures (TVs in birder lingo), ospreys and eagles overhead or flying towards you.
CLUES FOR IDENTIFYING OSPREYS
Many birders have trouble identifying birds in flight when they may only get a glimpse of a moving bird without time to note field marks. However, all it takes is knowing what clues to look for and it is much easier. Both the structure of the wing and the types of wing feathers can be crucial field marks, and they can be easy to learn.
Wing terminology used in describing ospreys.
Knowing the anatomy of the wing and comparing it to the human arm and hand makes it easier to understand how ospreys move and fly.
Typical wing anatomy of ospreys, hawks, and eagles.
• Wingspan: For their body size, ospreys have very long, rectangular wings. While the shape of the wings can seem to vary depending on the bird's flight pattern, a soaring osprey has relatively straight wings with a slight crook. The wingspan is the length of both wings from wingtip to wingtip including the width of the body. Try to judge the wingspanwhen the bird is holding its wings level to prevent distortion. Compare the length to other known birds or nearby objects for a more accurate assessment. An osprey’s wingspan can be 5 to 6 ft. (1.5 to 1.8 m) with the females generally larger than the males.
• Wingtip: Wingtips can be rounded or fairly pointed like the ospreys. When soaring, an osprey's primary feathers—the fingertips of the wings— have a wide splay that shows the individual feathers easily, even from great distances (see photo below).
Ophelia about to land in her nest, illustrating her bent wrists, dark carpel or wrist patches, dark bandit mask, barred tail, and very splayed primary tips or “fingers” or fringe.
• Wrist: The bend of a bird's wing is its wrist, and how that wrist is held can distinguish different species. As with wingspan, look when the bird is soaring when the wing is at a rest position. Look at the wrist joint to see if it is relatively straight or shows a stronger bend, and how that bend compares to the position of the head. Ospreys keep their wrists bent and have a prominent dark wrist patch. The density of the patch can vary and could be confused with the rough-legged hawk, but osprey's wings are generally darker than the hawk's overall.
• Patagium: The leading edge of the wing is the patagium, and its color can help identify a bird, such as the dark patagium on the osprey pictured above. Check if the whole patagium is colored or if it is simply splotched or speckled.
• Wingpit: A bird's wingpit is the equivalent to the human armpit, the area close to the body on the interior of the underside of the wing and is usually dark on the underside.
• Head Markings: Even from a distance, the white and brown pattern on an osprey's head is distinct. Check that the brown “bandit mask” or auriculars stretch to the back of the head rather than pointing down like tear drops on the cheeks, like they do for peregrine falcons and several other raptors. Ospreys also have individual markings on their foreheads and nape of their necks.
• Secondary Feathers: Ospreys have strong barring or banding on their secondary feathers making those feathers look darker compared to those on the paler inner wing. This type of barring can be common on many juvenile raptors, but even mature ospreys have it.
• Tail: The osprey's fairly wide tail has the same dark barring that is seen on its secondary feathers. The barring can be harder to see when the tail is closed, but is easily visible when the tail is fanned and is especially handsome when the light shines through it.
• Body: Most of an osprey's body is plain white, though some degree of brown speckling can be common at the base of an adult's throat and sometimes specks on their legs. Females have necklaces of around their necks and breasts of varying densities and thicknesses. The necklaces are made of white feathers tipped in dark chocolate brown and are very useful, but not fool proof for sexual identification. When the birds are in flight, the necklaces can appear diminished or vanish as the feathers move with their breast muscles during flight. Males can have plain white breasts or modest yet distinctive necklaces. Orpheus has a fairly dense necklace for a male and could easily be confused for one. Ophelia has a prominent necklace that extends from her throat down towards her belly.
Males are generally smaller and sleeker than females and their feathers over the summer get darker as the females’ lighten a bit. Juvenile birds may have a buff wash on the breast, but that color doesn't last long and can be hard to see from a distance.
• Sound: Hearing an osprey call is always a clear give-away that one is in the area. Their chirps are unique and cannot be confused with other local species. Listen to osprey recordings from the Macaulay Library of Natural Sounds. Two examples of osprey calls are 136252 Osprey and 169020 Osprey, but their calls are as individual as they are.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#19
June 21, 2014
Most birds grow following a "sigmoidal” or S-shaped growth curve. Osprey chicks grow slowly when they are first hatched, start accelerating when about ten days old, only to slow it down again at around thirty day, as they approach adult size. During these growth phases, female chicks get bigger than male chicks. At 14 and 11 days old, the chicks have begun this exponential growth spurt.
From age ten days until about 30 days old, the chicks will go through an exponential growth spurt. By day 35, the growth of the male chicks level off, while the females continue to grow becoming much bigger than the males. (Graph courtesy of The Osprey Project.)
Mom feeding chicks caught by a cam at a Natur Wildlife Trust center in Wales. The Welsh chicks are about the same age as the Salt Point chicks. The eldest chick (2 weeks) is just starting to come into 'pin.’
Osprey chicks hatch covered in white natal down feathers, which grows out of the same follicles that eventually will produce adult feathers. (For a wonderful discussion on feathers look at the Lab of Ornithology’s interactive discussion on feathers.) These natal down feathers are actually on the tip of the typical feathers, and as those feathers grow or pin, the soft fuzzy down drops away. On their tenth day, chicks begin to get their first real feathers. Watch these short animations of pennaceous and downy feather emerging to get an idea of how they develop.
A 14 and 17-day-old chicks at the Jamaica Bay Wildlife Refuge in New York, 2012. The pin tracts from which the future feathers will grow can be clearly been seen on the chicks.
As a feather begins to grow within a covering called a white sheath, it develops its central shaft, color, and pattern. Blood vessels nourish the growing feather until it is fully formed, then the blood vessels wither away. This allows the feather to harden and stand up to the pressures of the surrounding environment. Once the feather is fully formed, the sheath bursts open and falls off, or the bird removes the sheath with its beak, and the feathers unfurl from the packaging.
A fully formed feather has a central shaft, with many parallel branches called barbs on both sides. On many feathers, such as flight and tail feathers, each barb has small barbules and even smaller barbicels with hooklets, tiny parts that interlock to keep the surface of the feather smooth and weatherproof.
Feathers grow out of little pits in the skin called follicles, which lie in neat rows in patches called feather tracts or pterylae (see diagram below). In between the feather tracts are patches of bare skin call apteria. The feathers grow in thickly and overlap so no skin will eventually show. The arrangement of feathers allows the birds to function with less feathers overall, somewhat like a “feather comb-over,” which drastically reduces the total weight of feathers—another adaptation for flight.
The arrangement of feather tracts and bare skin is collectively known as pterylosis, and this differs from one group of birds to another. While scientists do not know the reasoning behind these differences, they use feather tract patterns to determine how to classify and group birds.
The adult feathers will periodically be replaced by molting, which I’ll address in a later blog. To facilitate discussions, I’ve labeled the general anatomy of an osprey and parts of their wings below.
All birds spend a lot of time preening, combing their feathers into place, removing ectoparasites, and spreading protective oils on them. When the chicks start preening, it’s a bit like a toddler teething. The chicks start preening as their feathers begin to push out, which is presumably a pretty itchy process. Once their feathers are out they spend a lot of pushing, brushing and running their beaks through them to keep them in good shape in preparation for flight.
These emerging dark feathers are “in-pin.” The young osprey will preen and peck away at the white sheath until they crumble.
A bird can move each of its feathers independently, using tiny muscles in the skin. This helps a bird place its wing feathers, for example, into position to make a turn or slow down. The ospreys can also raise and lower their nape feathers or hackles to some degree.
Immature birds have much softer feathers than the mature birds. Some speculate this offers immature birds need more cushioning against bumps and tumbles. Immature birds do not care for their plumage nearly as well as mature birds do and therefore are seen more frequently with feather breakage or feathers in need of straightening.
Types of osprey feathers.
An osprey is covered with a variety of feather types, which all look different and are modified to serve certain functions. Contour feathers on body, wing, and tail give a bird a streamlined, aerodynamic shape reducing drag in flight. Down feathers are the fluffy feathers that grow near the skin under contour feathers. Down traps warm air, insulating the bird from cold and heat. The reason why down is so fluffy is because the feathers lack the barbules needed for a smooth surface.
Types of Feathers on Osprey Wing
Contour feathers have a lot of structure and are what give a bird her shape. These lie against the body and can be anywhere from very small to quite large and substantial on the bird. Flight feathers are the largest, most substantial, and most impressive of the contour feathers. These vary widely across the bird's body with regards to their shape, and vary from species to species. These are the tail feathers, the primaries and the secondaries found on the wings.
Feathers are some of the lightest but strongest materials in nature. Flight feathers, so necessary to the osprey’s existence, are extra strong. Feathers can withstand raging winds, rain, snowstorms, high doses of sunlight, and collisions with tree branches. Feathers are flexible too. If bent, a feather shaft will straighten back up.
An osprey’s feathers are either varying shades of brown and white or all white on the breast and belly. An osprey’s feathers are colored brown by a pigment called melanin, which is made within the body. Melanin absorbs certain wavelengths of light and reflects the rest. Humans see the reflected light as shades of brown. The white feathers lack all pigment. Melanin also strengthens feathers. As a result, the brown and white feathers, which bear the brunt of flying, are stronger than all white downy ones.
One of last year’s Salt Point chicks peering out through the nest. Look for the chicks orange eyes looking out at the happenings below.
The chicks are well camouflaged from above; their light stripe resembles the top of a stick and their dark sides look like the shaded area. The chicks have learned to lie low—a defense from aerial predation and all assume this posture as their mother sounds a warning call—a harsh Cheerp!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#18
On Osprey Time
June 20, 2014
The Salt Point ospreys are especially delightful to watch since they don’t seem to mind us being voyeurs. They do everything out in the open—including building their nests, courting, breeding, rearing their young, “fish kissing,” fishing, and learning to fly—on their own timescales, according to the changing sun; living on osprey time. When we unburden ourselves with the trappings of our days we humans can really enjoy the immensely peaceful life on Salt Point.
"The secret to life is enjoying the passage of time." ---James Taylor
And the secret to osprey watching is to just enjoy the passage of time. Even the duller minutes are moments of serenity otherwise left unappreciated. Living on osprey time requires stillness, and gives one the opportunity to go deeper into the rhythms of the lakeshore. Let go of the clutter, go back to the 1971, BE, HERE, NOW in the mindset of Ram Dass. Turn off the narration of life and focus on your surroundings. Endeavor to see do as the osprey does, to see what it sees: This is a powerful yet simple exercise done by humans for millennium, with the fringe benefits of tranquility, greater awareness, and deeper understanding. It’s an experience similar to fishing when the rocking of the boat lulls you into a peaceful state where nothing else matters. You are one with the water, the sound of the waves, and thinking like a fish.
Here, on Salt Point, life is attuned to the Lake: the wind and the waves—what’s above and below. Colorful butterflies visit the wildflowers scattered about the shoreline and large meadow. Tiny ants explore the pebbled beach while on the larger scale, frogs, turtles, harmless water snakes, fish, songbirds (specially my favorite orioles and vireos), waterfowl, shorebirds, turkey, mink, raccoons, fox, coyote, and a growing number of deer are all part of the Salt Point ecosystem. Later on in the season, jumping spiders, grasshoppers, cicadas, and bullfrogs will keep the rhythm as stunning dragonflies, damselflies, and more butterflies—the bedazzled jewels of the Salt Point (see our future checklist and featured photographs by Dr. Meena Harbel)—fill the air.
The timekeeper of osprey time, the sun, determines where and when the fish will be, hence the tempo of the nest. All activity revolves around when Orpheus delivers meals—in other words, the osprey family lives from fish to fish. In between, they young spend their time digesting, testing their growing wings and bodies, and sleeping as the parents care for them. The real action, the time of true excitement for the osprey, and many families, is mealtime. These are the best times to see the chicks as they spring into action vying for food.
I have health issues that prevent me from being at Salt Point as I was last year from dawn to dusk every day. If you have any interesting sightings or photographs of the Salt Point ospreys, please email them to me. I am especially interested in the times Orpheus brings fish to the nest, the species of fish (if you can tell or describe it), and the outcome of the fish. Orpheus usually eats the head of the fish before giving it to Ophelia, but sometimes he’ll bring her a whole fish. She is the one that usually doles dinner out to the kids although last night, Orpheus fed the chicks for at least ten minutes and also spent another ten giving Ophelia kisses of fish or rather tender morsels of the poison du jour. Please send me your osprey sightings I welcome reports on the ospreys when I am not at SP and hope you will email your sightings to me.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#17
Mombrella
June 20, 2014
Now that the chicks are older and have enough feathers to thermoregulate or keep their body temperatures consistent, they no longer require constant brooding. As she’s exhibited over the last week, Ophelia now spends her days standing above her chicks striking the “Mombrella” pose with her wings partially spread out to shade her chicks. At long last, two very healthy dark little ospreys with bandit masks can usually be seen panting near their mother’s breast or gaping for food during meals. The eldest chick hatched on June 7, 2014, twenty days ago and the second 17 days ago. Both are getting their full compliment of feathers. I have not been able to determine if a third egg was laid and so can’t tell if there is a smaller third hatchling is in the nest; only time will tell.
Mombrella Ophelia shades chicks as they pant.
Ospreys get their drinking water from the fish they eat, so deliveries on hot days quench thirsts as well as appetites. Ophelia has been in her “Mombrella” pose for hours already today and will continue to hold the pose until sunset. It must be exhausting to maintain that position for so long, especially when July temperatures will soar to the 100°F mark, but she is a dedicated model of the maternal drive.
Osprey watching definitely has it highs and lulls in terms of action, but there always is something going on, even if the birds are just sleeping or resting. They are constantly aware of their surroundings and the pulse of Salt Point. They are anything but shy and let you know immediately, by crying and flying circles overhead, if you bother them.
Orpheus on left, Ophelia standing, with a chick in the middle.
Besides having markings (on their forehead, nape, and chest) that distinguish each osprey from another, and occasional distinctive feather defects, I find each osprey has its own personality. Ospreys are highly variable in how they relate to their mates and offspring. Ophelia is a very dedicated mother and much less demanding, as determined by her level and frequency of begging, than other osprey I have observed. Begging is especially prevalent in dense colonies, such as the crowded non-migratory populations found along Florida waterways.
Mombrella Ophelia crying to Orpheus for the last fish of the day.
Orpheus is a good provider and an attentive young father, spending much of his time guarding the chicks. He’s also takes time to give Ophelia the “kiss of fish,” as I call it. It’s technically called mated feeding, but seems tenderer than that name implies. Orpheus sits in the nest, pulls off pieces of meat, tilts his head just so, and feeds them to Ophelia, who receives them in a very deliberate fashion, with her bill tilted in the opposite direction. Over the years, as their relationship develops Orpheus could become more responsive to Ophelia’s begging; it all depends on his disposition.
The Salt Point ospreys are uniquely tolerant of onlookers and have accepted the Lansing community as part their environment. My husband and I just completed our second monthly survey of all 40 or so nests around Cayuga Lake and found, with a few exceptions, that the osprey parents were much more nervous in my presence with camera than my last survey. Most required a buffer of at least 300 or more feet before they would settle down. Since all these osprey were probably on young chicks, it will be interesting to see if their behavior changes over following visits this summer. One 8-9 year old nest built between two houses and thought to be one of the oldest osprey nests in the Route 90 corridor, has easygoing parents similar to Salt Point’s pair. A few other nests, such as the nest next to the Harris Station in Cayuga, also in proximity to people, are slightly nervous. The other nests located on utility lines near roads or in fields tolerated cars, but related negatively to human traffic within the 300 foot buffer area. The Bald Eagle nests in the areas I visited required a buffer of three times that distance and would be very difficult to support in a park setting.
Not only are we lucky to have a family of osprey living with us at Salt Point, we happen to have a very congenial and accepting pair that don’t mind us being a part of their lives!
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#16
Community Care
June 19, 2014
As many visitors to Salt Point commented, my wooden chair “On Osprey Time,” located across from the osprey platform, disappeared a few weeks ago. It had been handy to have it there for my observations and for anyone wanting a rest. But, the joke is on them because the chair was only stable where I’d stationed it, and that area had been recently invaded by poison ivy. So the culprit walked through a poison ivy patch, only to have the chair probably fall apart as it was taken.
Even though I had initially expected the chair would be taken, the longer it was there, the more I began to count on it being there. My disappointment is that vandalism still goes on at Salt Point, from my disappearing chair to cars and pickups tearing up the lawn to used needles left on weekends by the boat launch.
It has taken years of community efforts to make Salt Point a safe, family-oriented natural area for all to enjoy and more improvements are coming. The Cayuga Bird Club installed a bluebird nest box trail in the large meadow and placed species-specific nest boxes along the interior birding trail—look around the meadow for our young bluebirds and tree swallows! Merganser boxes will go up in the fall. The Friends of Salt Point recently donated four picnic tables made by the Lions Club, three Leopold benches, and a Little Free Library to enhance the community’s visits to the point. Dozens of donated trees were planted this spring with more plantings planned for the autumn.
It takes a village to create something worthwhile and it will take one to protect it our new community jewel—Salt Point! Learn how to help.
The Leopold Bench, originally designed by Conservationist Aldo Leopold, is a simple, utilitarian bench made of tough black locust. The bench at the far west point will carry Aldo’ words:
"There are some who can live without wild things, and some who cannot" —A Sand County Almanac
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#15
Fishing
June 16, 2014
Being out on Salt Point in the early morning is my definition of peace. Time seems slower as the constant wind and waves lulling all with a gentle rhythm. Only bird songs punctuate the wind. Wispy cirrus clouds drift overhead as Orpheus, standing guard at his usual diagonal post, closes his eyes for a moment’s rest. The sudden explosion of twenty quacking mallards taking flight from the north cove flapping overhead, silhouetted by the bright sun, woke Orpheus. Ophelia took the occasion to remind her mate that it was time for more fish.
Even though fish are abundant in Cayuga Lake and Salmon Creek, it doesn’t mean they are easy to catch. Ospreys rely on their sharp vision to detect fish through the water column and anything that impacts the clarity of the water makes the job harder. Orpheus has his work cut out for him supplying fish for his growing family, and weeks of thunderstorms, winds, and heavy soil run-off clouding the lake did not make it easy. At four years old, Orpheus is a skilled hunter and over the summer will feed his family a selection of lake trout, yellow perch, brown bullheads, pumpkinseed, bluegills, rock bass, white perch, white bass, small-and large-mouthed bass, carp, suckers, and the occasional goldfish. Orpheus has to catch 4-6 good-sized fish a day to feed himself and Ophelia and more for the young ones. A brood of three young chicks, such as they raised last year, initially requires one pound of fish daily, increasing to two pounds in a week, and more the following.
Most of the fish ospreys catch weigh between one-third and two-thirds of a pound, although Orpheus has brought home a few handsome lake trout, a bass, and pike, and a carp all tipping 2 pounds. The heaviest prey recorded in the scientific literature weighed two and a half pounds, more than half of the bird’s body weight, although fish up to four pound have been reported. Ospreys are opportunistic hunters, taking whatever fish, or other animal, they spot in the water. More than 99% of the time they live on fish, but have been known to eat aquatic animals such as frogs, turtles, and water snakes, and rarely ground squirrels and mice. There is even one report of an osprey taking a baby alligator.
I keep track of the fish species and size that Orpheus feeds himself and the family to better understand the food availability along the Lansing shores and the general health of the fish caught to get an overall picture of the health of Cayuga Lake and Salmon Creek. As mentioned in Blog 4, my fish weights are estimated based on standard length using weight calculators for trout, bass, and pike, and other species and the DEC ruler-based version. It’s the first project I’ve done that ever married my love and studies of fish and birds so completely.
Occasionally, Orpheus will drop a fish in flight or one falls from a perch or the nest while being eaten, but the ospreys never retrieves them. Unlike eagles that eat carrion, ospreys only pick up live fish and once it dropped, it’s gone—no 3-second rule. That’s when I go into action and try to locate the dropped fish, as it’s an opportunity to physically measure, weigh, and study the fish. I also regularly search around the platform for fish bones to use for fish measurements. Ed Brothers, a local Ichthyologist, studied the otoliths from a perch Orpheus had dropped and determined it was eight years old.
Orpheus, like all ospreys, can plunge only to a depth of three feet and is thus limited in the proportion of the lakes fifty or so fish species available to catch. The season and weather also influence prey movements and availability, making some species easier prey at various times. For instance, on warm spring days in Cayuga, pike come into the shallows to spawn and feed. On still days, trout rise to the surface to catch flies. Individual osprey must learn the subtleties of their particular environment and over time use them to seek out specific prey. They also learn the appropriate angles of attack used for various types of fish—long, shallow dives for fast-swimming fish near surface and steeper dives for slower fish found deeper in water.
I never tire of watching osprey dive for fish and always cross my fingers until I see the results. My attempts at description below fall far short of the grandeur involved in the actual ballet, and so I’d suggest watching the spectacular diving footage from Arkive again as a prelude to my cursory attempt to describe it. In a later blog, we will discuss the osprey’s many adaptations and senses involved in fishing. I especially enjoy the Olympic-style inventiveness of the osprey swimming to shore with a bass it cannot lift out of the water.
Ospreys tend to use two fishing techniques as Orpheus demonstrates at Salt Point. He will sit atop a waterside snag, peering into the water, until prey swims by. With one quick dive, he drops and usually scoops it up. In 2013, Orpheus favored the iconic snag at the mouth of Salmon Creek, as did his three offspring when they were learning to fish. It had the only natural nesting cavity that I know of on the point. However, the snag broke in half during the winter and now serves the same function for the kingfisher. I have seen Orpheus perch on it, but it is too short to give him visibility. A few other trees on the point and along the creek serve the function of the old snag, but nothing can quite replace it.
The grander, more majestic technique of the fish hawk has been caught in photographs by Andy Morffew, and takes place high in the air where he’ll fly in a slow circle over the lake, scanning the
surface at a height of about 100-300 feet. He flies steadily flapping, maintaining altitude as he
swivels his head looking intently at the water. When he spots a fish near the surface he stops
mid-air and hovers, fluttering with wings in place like a giant hummingbird with his head pointing downward. He follows the fish’s movement, anticipating his actions, and suddenly dives toward it.
With wings folded he plunges fully committed at over forty miles an hour, still keeping his eyes trained on the trajectory of the moving prey. At the last second before hitting the water, he pops
“a wheelie,” thrusting his wings back and his legs forward, as his deadly talons close on the slippery fish with lethal force. Fully immersed in the water, he secures the struggling fish in his talons. Beating his powerful wings furiously, he lifts both his heavy, water-soaked body and his
prey from the water and rises into the air. About ten feet over the water, he shakes the water off like a wet dog, he positions the fish belly down, head first facing into the wind, and cries out victoriously—Cheereek! Cheereek! Cheereek!
The Doggie Shake 1
The Doggie Shake 2
The Doggie Shake 3, performed without a fish in tow.
The supreme aerial fisherman, an experienced osprey in good weather can catch a fish at least once in every four tries, taking on average of 12 minutes to spot and capture its prey. Orpheus is not up to that level of precision yet, but he is a good provider and continually learning, improving, and honing his abilities.
British poet Steve Hagget (1977) vividly describes an osprey fishing in this excerpt from The Osprey. I find myself holding my breath as I read about the “rippled muscles flow” and the “sinews, strained, unleashed.”
The Osprey
Upon one battered cypress perched,
Amidst the morning haze,
Bright eyes stare out from part-cocked head
With piscicultural gaze.
Intently focussed on the brook,
That glides beneath the tree
Alive to every shadow’s sound
Yet never truly free.
For choicelessly these eyes are drawn,
As waters break below
And like a flash a head snaps back
And rippled muscles flow.
Within the slightest moment’s breath,
Two mighty wings released,
Two claws full-stretched, two legs reach out
The sinews, strained, unleashed.
The beaten air the only sound,
As time itself stands still
And, tracer-like, on charted course
The Osprey meets its kill.
With consummate and practiced ease
The painless end begins
The single deadly blow is dealt
As sharpened claws sink in.
Then up away into the dawn
And time resumes its course
Two final beats – then disappeared
Is this magnetic force.
—Steve Hagget
A biography of Andy Morffew and the other superb photographers featured in On Osprey Time and the Ospreys of Salt Point Website will be uploaded fairly soon in the Ospreys of Salt Point Gallery Section.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#14
First Weeks
June 14, 2014
Nest cleanliness is crucial to raising healthy chicks. Even at the age of a few days old the Salt Point nestlings attempt to back up to the edge of the nest to excrete a mix of white uric acid and feces. This skill takes time to perfect and in the meantime, Ophelia is often on the receiving end. The areas below the nest and eating perches are ringed with these odiferous, oily droppings called "whitewash." The ring of muscles around the osprey’s single vent or cloaca, the cloacal sphincter, has a strong ejaculatory force to expel these droppings out of the nest. As depicted in the photo below, adults have “jet-propelled” feces that shoot several yards away from the nest.
Orpheus’ fishy, oily defecation over the side of the nest.
After hatching, Ophelia probably eats the leftover eggshells, as do many birds, to recoup the lost calcium and other minerals, although this has not yet been documented in ospreys. Both parents nibble at the leftover fish scraps left in the nest, and the nest it is anything but a sterile environment. Nest parasites abound in most bird nests making preening (grooming) essential.
Orpheus and Ophelia seem very capable of meeting their growing responsibilities. Orpheus regularly delivers fish to his mate, often after he has eaten the head, and continues to replenish the nesting materials. Ophelia, and only her, broods the chicks almost continuously for the first two weeks, keeping their body temperatures constant until their feathers grow in.
The chicks spend much of the first two weeks eating and sleeping. They grow rapidly, doubling their weight in the first week alone.As seen on the osprey cams, the older they get, the more frequently they attempt to move about exploring the nest and flapping their tiny wings. At ten days of age, the chicks become fairly mobile, quickly approaching the female when she feeds them and backing up to eject feces over the rim of the nest. About this time their first down is replaced by a dense, wooly, dark colored, second down, which lasts another 10 to 15 days. A conspicuous light brown streak runs along their spine, the feet turn bluish-grey and the beak and claws turn black. At two weeks of age, rusty golden feathers start replacing the down on the head and neck and darker feathers appear on the rest of the body slightly later.
The real flurry of activity comes when Orpheus delivers a fish to his broods and the tiny hatchlings get excited uttering faint little cries that can be heard when all is quiet on the lake. Ophelia is handed or excitedly grabs the fish from her mate, pins the fish in her large talons, and rips into its live flesh with her bill. This Animal Kingdom savagery is followed by a delicate display of maternal care as she gently takes the torn morsel, tilts her head just so, and carefully places the fish in the gaping mouth of one of her young. Last year, these tender early moments were visible from the ground, but the nest is too deep to see this yet.
Mother ospreys typically feed the chick that begs closest and most forcefully until all the chicks are fed. The eldest is usually fed first because it tends to be the loudest, but there is always plenty for everyone. The chick’s crop stores fish helping them stave off hunger in between meals. Once satisfied and their crops full, the chicks collapse into a ball and sleep until the next meal.
Ophelia, sometimes joined by Orpheus, finish the fish and swallow the fins, scales, and other indigestible parts. Much like owls, ospreys periodically cough-up pellets containing these indigestible remains and expel them out of the nest.
Under normal conditions when food is abundant, dominance hierarchies usually do not develop, but sudden food shortages can force osprey nestlings to fight over food. As mentioned in Blog # 10, cainism sometimes occurs in ospreys in the face of severe food shortages.
A bundle of chicks sleep after being satiated. (Screen capture Hellgate cam 2013.)
The nest is a dynamic structure throughout the season: Orpheus and Ophelia continually add materials and rearrange them, just as the wind and rain continue to test out their designs and streamlines. As the young chicks grow, so will the nest to insure there is enough of a boundary for them between life and death. Ophelia continues to add and freshen the nest lining around her chicks to keep parasitic and insect infestations to a minimum.
Sunny days like today are also important in drying out the nest from the frequent rains and thunderstorms of June. Ophelia doesn’t have high temperatures yet to contend with, but she must shade her rapidly growing offspring from too much solar radiation. For Orpheus, the sun will help the fishing, but the wind is still against him. He doesn’t need the lake to be mirror-calm to fish, but the smoother the surface, the better. After all, there’s always a breeze around Salt Point, making it a favorite spot for para-boarders (kite surfing), swallows, gulls, and osprey.
When not fishing, Orpheus guards the nest. Sitting upright with intelligent eyes scanning the sky, he is the picture of elegance and majesty. He’s a top predator in the food chain and he looks the part with his enormous hooked bill and talons. Gone are the days of sitting and waiting now that there are mouths to feed and chicks to tend. The difference in Orpheus’s behavior over the breeding season is fascinating as he adapts to his changing roles from bachelor to mate to proud papa and back again. Prior to incubation, he tended the nest site, claiming his territory and mate. During incubation, he spent much time away from the nest site, although he shared in the incubation when Ophelia fed. Now that there are chicks, he’s either on guard at the nest platform or fishing.
Proud Papa Orpheus, guarding the nest from his perch, looks at his nestlings with curiosity.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#13
Hatchlings
June 13, 2014
A typical bird egg showing the yolk sack. The amount of yolk or food is different in each bird species and helps determine the developmental stage at which the chick will hatch—precocial or altricial or somewhere in between.
The osprey chicks at Salt Point are still too hard to see, but this should be changing soon. We can see Ophelia tear off bites of fish and feed them tenderly to invisible mouths below and the occasional squirt of feces over the nest edge. However, thanks to the many osprey cams, we can follow other nests and track the developing young.
Birds hatch at different levels of development and require varying degrees of parental care. Birds are classified into one of two main types: precocial and altricial with gradations of conditions in between. Precocial species, such as waterfowl, upland birds, and shorebirds, hatch with a head start. Precocial birds lay large eggs with ample food (the yolk) and their incubations are long. However, they are born fully feathered, sighted, mobile, and able to feed themselves. Other than showing the chicks food sources and guarding them until they are old enough to be on their own, there is little further parental investment required.
On the other side of the scale are the helpless altricial birds, which hatch with their eyes closed, covered with little or no down, and are totally dependent on their parents for all their care. Songbirds (passerines) are all altricial, laying small eggs containing limited amounts of nourishing yolk and have short incubation periods. Once the embryonic chick consumes the yolk, they are forced to hatch in a premature state while their brains and delicate nervous systems are still developing. The young must be brooded for an extended period after hatching to maintain proper temperatures for growth and development.
In between these divergent breeding conditions are down-covered semi-altricial species, which requiring parental care in the form of brooding, feeding, and protection. Ospreys and other hawks, eagles, and herons hatch with their eyes open and owls hatch with the eyes closed. The young ospreys are almost helpless and need very close parental care during the first weeks of life. They are unable to maintain their own body temperatures (thermoregulation) and must be brooded constantly by their mother until they are 7-10 days old.
The new chick hatches looking like miniature dinosaur weighing about 1.7 ounces. It is an ungainly little thing with an enormous bill and talons, which seem much too big for their small bodies. It’s hard to imagine the exponential growth that will turn this helpless blob into a majestic sea hawk, able to fish and migrate over 4,000 miles at only four months of age—now that is awesome!
The newborn chick is unable to raise its head and lies limp for the first few hours. Later on in the day, the chick can move weakly, but it is capable of begging with its wide gape for a few moments. When osprey chicks hatch, they are covered in pale brown and buff down with a brown mask. Their deep fox-orange eyes open just hours after hatching, their body is covered with down feathers, and they can actively pick chunks of food from their parent's bill rather than be passively feed.
A repeat photo from Blog #11. A helpless new hatchling resting in the sun. (Screen capture from Hellgate Osprey Cam 2013)
These natal down feathers are essential to the survival of the chick, providing insulation and camouflage. While adult birds also have body down feathers, grown from follicles devoted to solely to the production of these down feathers, natal down grows out of the same follicles that eventually will produce ‘typical’ feathers. These natal down feathers are actually on the tip of the typical feathers, and as those feathers grow, the soft fuzzy down drops away.
The newborn ospreys enter a new phase of development fueled by the high-caloric fish fed to them by their parents. Even so, the immature brains of the chicks require weeks to develop under constant parental care. They eventually catch up to the precocial species and fledge from the nest fairly independent.
By the second day the chick is active, holding its head up, bouncing, waving its wings, and issuing soft peeping calls. In a few more days, it will start begging for food at any movement on the nest's edge, standing weakly with its bill open or gaping, and its neck extended high. Even at one and two days old they have a masked appearance.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#12
Mutalism
June 10, 2014
Since ospreys live on fish, smaller birds have nothing to fear from them and often nest underneath osprey nests for protection. House Sparrows are nesting under the Salt Point osprey nest again as they did last year and can easily be seen coming and going all day. It's common to find smaller cavity-nesting species, such as House Sparrows, European Starlings, Tree Swallows, Barn Swallows, and Common Crackles nesting within or underneath osprey nests.
Osprey nests are not noted for being particularly clean although the young chicks and adults do defecate over the rim of the nest. If a fish is larger than the ospreys can consume, bits may be left in the nest to rot. The debris can accumulate, attracting pests to the nest. Although it has not yet been studied, it is thought that the smaller birds, in addition to getting safe nest sites, may benefit by eating these nest pests and parasites. Because this also benefits the ospreys, it is considered mutualism or a mutalistic relationship.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#11
Happy Birthday!
June 7, 2014
Newly hatched chick next to pipping egg. (Screen capture from Hellgate Osprey Cam 2013.)
Typical of asynchronous egg layers, each of Ophelia’s eggs is a different size, weighing between 2.1-2.6 ounces. The first egg laid will be the largest, and each egg laid is successively smaller. The eggs will then hatch in this same sequence after about 35–43 days of incubation (the average for the northeast). In ospreys and other hawks and eagles, this size advantage gives the embryo in the first egg a significant developmental head start over the eggs in the rest of the clutch. In addition, the first egg hatches several days in advance of the second, another valuable perk of being Numero Uno. The youngest chicks are markedly smaller than the eldest at birth. However, provided there is enough food for all, the chicks grow rapidly on their protein-rich diet of fish and soon catch up with each other. By the time they are juveniles in September, the female chicks will be bigger than the males, regardless of their birth order.
We have no way of peaking into the osprey’s nest cup at Salt Point to see the exact moment the first egg starts hatching, but clues from the parents’ behavior help narrow it down rather effectively.
During the long 5-6 weeks of incubation, the brooding bird’s attention is directed outwardly, toward its surroundings, focusing on guarding the nest from intruders and predators. Every hour or so the bird incubating the eggs, usually the female, will poke around in the nest cup, rolling the eggs to keep their temperature at uniform 99 °F and adjusting nest materials.
Two to three days before an egg hatches, the embryo inside begins peeping to its parents in the outside world. At the same time, the embryo is busy “pipping,” hitting the eggshell from within with its special “egg tooth.” These noises capture their parent’s attention, redirecting their focus from their surroundings to the events in the nest cup. Pipping can last several days. During pipping, the embryonic chick rotates in the shell, tapping the sides with its egg tooth to crack the eggshell. The chick’s neck is relatively strong, enabling the beak to hammer at the shell and eventually break through the shell.
From watching other pairs on osprey cams, it is clear that Ophelia and Orpheus are able to notice any changes in their eggs and know that something is occurring. Both parents seem uncharacteristically nervous, edgy, and very interested in something within the nest. During the quietest of moments, you sometimes hear Ophelia quietly chirping to her brood. This critical period is also when the parents imprint on, or learn to recognize, the sounds of their chicks.
About 12 hours before hatching, the pipping pays off and the embryonic bird starts breaking through the shell. At first many little holes appear, which finally give way to larger cracks until the chick can emerge. The chick’s egg tooth—the white small, white, temporary outgrowth of the beak (upper mandible)— is strictly for this purpose. After several days of pipping, the chick will struggles free of the shell without any outside help.
New hatchling resting in sun. (Screen capture from Hellgate Osprey Cam 2013)
As soon as the first egg hatches, usually in the early morning, the behavior at the nest goes through a dramatic change. Prior to hatch day, Ophelia would take the fish Orpheus gave her and have her meals in a nearby tree. However, from the moment the first egg hatches, she no longer leaves the nest. After she receives the fish from Orpheus, she carefully breaks off pieces for her new chick, and then feeds herself. That’s exactly what she did on Saturday, June 7, 2014 when her first egg hatched after 28 days of incubation.
Female Osprey brooding two chicks and an egg in Maine last summer. Notice the nets and other debris collected in her nest. (Screen capture from Audubon Osprey Cam, 2013.)
These early days of parenting are peaceful at the nest. The pair has the luxury of enjoying a few meals together at the nest before there are too many demands on their time. Orpheus watches over his new family, guarding them from the diagonal perch as Ophelia cares for the first chick and keeps the other eggs warm and safe.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#10
Order of Hatching: Synchronous vs. Asynchronous Hatching
June 6, 2014
It’s 6:37 am on June 6, a typically glorious Salt Point morning and already 68 °F. Baltimore Orioles sing the lead with sparrows, blackbirds, catbirds, and vireos as backed-up. Orange and purple wildflowers already grace the lakeshore, phlox blooms in the meadows. The snow from the cottonwoods drifts in the breeze and if you didn’t have allergy issues before, you do now. Orpheus gave Ophelia her morning meal just now, which she immediately took to a perch by the railroad tracks to eat. Taking his turn at incubation, Orpheus carefully walked onto the nest to nestle the eggs. It is crucial to the proper development of the embryos that they are kept at constant 99 °F and protected from solar radiation for the entire 5-6 weeks of incubation. To maintain this constant temperature, the incubating adult gently turns the eggs every few hours if not more often and adjusts their posture to increase or decrease airflow to the eggs.
As detailed in the egg laying section of Family Life at Salt Point, osprey eggs are cream colored and chicken-sized with deep cinnamon-brown and chocolate streaks and blotches. These patterns vary between eggs, but are unique to the female. Each year Ophelia’s clutches will look different, but she can distinguish them as her own—a critical ability when nesting near other osprey. When seen from above, these unique patterns also offer superb camouflage from marauding aerial egg thieves like gulls, Great Blue Herons, and crows.
Synchronous vs. Asynchronous Hatching
Whether a clutch of eggs hatches all at once or sequentially is determined by when incubation starts. In many species, such as the American Robin or Mourning Dove, the female bird does not start her incubation until all her eggs are laid, so that the eggs all hatch within a few hours of each other. Synchronous hatching is especially prevalent in precocial birds, like shorebirds, ducks, and chickens, which are fully feathered, mobile, and independent from the start. Synchronous hatching affords large broods of precocial species like the Mallard ducklings and Canada goslings at Salt Point safety in numbers.
In many other birds, including the osprey and other hawks, incubation begins with the first egg and the eggs hatch asynchronously in the order they were laid. Researchers think asynchronous hatching evolved to allow ospreys to raise the largest number of offspring that food resources will allow when the food abundance later in the season is unpredictable. In off years when there is an unexpected food shortage, especially in tidal areas where schools of fish migrate through, brood reduction can occur, with the smallest, youngest chick or chicks not surviving. However, brood reduction does ensure the survival of the hardiest chicks during these times of extreme stress.
One form of brood reduction is called cainism—the killing of a nesting bird by a larger, older nest mate—regularly occurs in eagles and hawk species, but is extremely rare in ospreys. In fact, before osprey cams started revealing the intimidate details of the nest, it was thought that cainism did not exist in ospreys until several instances were recorded after severely bad weather created drastic food shortages. Let me stress that such behaviors are the rare exception to the rule, and not likely to occur in the fish-rich waters of Cayuga Lakes.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#9
June 5, 2014
(Pardon the delay in posting as our web master is on a delightful vacation.) Many visitors to the Salt Point nest have been worried the ospreys are not incubating their eggs. Rest assured, there is adult on the nest at all times—we just don’t see it. Ospreys continually add to their nests year after year and the Salt Point nest is a few inches deeper this year, just enough so that you can’t see the incubating adult’s head. I am afraid it will be harder to see the chicks during their first weeks as well.
Ophelia does most of the egg incubation, including long restless nights with a few catnaps looking out for danger from Great Horned Owls. Orpheus does the fishing and spells Ophelia during meal times. As soon as Orpheus gives her a fish, Ophelia takes it to a perch to eat and he takes over incubation until she returns.
During these meal breaks, Ophelia often takes time to wash her talons or perhaps bath in the lake, fly a bit for exercise, and perhaps pick up some soft moss or algae for the nest lining before returning to the nest. The first egg will hatch sometime before June 11 and the others will follow in the order they were laid. (Read more about the hatching process in my upcoming blog # 10).
If you ever have any questions, please feel free to ask.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#8
June 3, 2014
Ophelia is in her last week or so of incubation, but instead of it being the relaxing, monotonous time period before the chaos of caring for babies begins, it's been anything but calm. There were many intruders at the Salt Point nest last year—unmated ospreys looking for nests and mates or homeless mated pairs—cruising the nest platform threatening and pestering the pair well into July, but the number of homeless intruders in 2014 is up by 30%. Intruder ospreys are pestering established nesting pairs with little hope of success, wasting the ospreys' energy defending their nests and keeping Orpheus and other resident males from fishing. In places with less abundant food or higher breeding densities, stress from intruders can be so intense it can cause nests to fail.
Why are there so many intruders suddenly? My husband and I surveyed all the active osprey nests we could find in the Cayuga Lake basin based on reports and found many surprises. Most importantly, Cayuga Lake is experiencing an osprey population explosion. In 2009, there were 5-6 active nests on the lake. Five years later in 2014, we found 37 active nests and those are only the ones viewable from public roads.
This astonishing sevenfold increase has a population doubling time of less than three years (and that number still does not reflect the unreported off-road sites)! We could have over 70 ospreys pairs on Cayuga Lake in 2017, 140 pairs in 2020, and theoretically. 280 osprey pairs nesting here by 2023! Renowned Cornell osprey expert Alan Poole, from the Laboratory of Ornithology, saw a similar, but smaller, population growth in southeast Massachusetts, where the osprey population had a doubling time of roughly 5 years at the peak of its expansion, and the peak lasted about 10-15 years! Incredible!
The housing shortage is due to humans removing most of the ospreys' natural nesting sites from our landscapes—the "unsightly," "risky," ancient dead trees capable of supporting the ospreys' bulky nests. Now ospreys need our help to build safe nest platforms and lots of them. Out of the 37 nests I photographed on the lake, ten appeared to be built under hazardous conditions. Two have since been repaired and the utility company will remedy the others if the nests are indeed problematic. In addition, without ample, safe nesting sites, the ospreys will keep building in hazardous locations causing potential fire hazards to ospreys, humans, and equipment, and requiring fast, expensive, last-minute solutions.
We can't depend on the utility companies to do all the work; other business, local governments, organizations, clubs, and birders in the area have to do their part. Early this fall we hope to organize a meeting of local stakeholders to discuss planning and building platforms for the ospreys of Cayuga Lakes. Look for updates on the Salt Point osprey page.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#7
May 19, 2014
Even though most of the local ospreys are incubating eggs, there is still competition for nest sites at Salt Point and around the lake. Intruding ospreys, probably some of who have lost their mates or nesting sites, pester the Salt Point pair, vying for their property rights almost daily and May 19th is no exception. These confrontations can be very aggressive and, according to the literature, some ospreys are injured or die during them.
Male intruders routinely fly by other osprey nests, testing to see if there are available mates in the area. As they cruise by, they call out to the females and if they are not met aggressively, the intruding male will come in for a closer look and hopefully find a receptive female. To find a nest and unmated female is to win the jackpot. That is one reason why Ophelia never leaves her nest unattended and is quick to rebuff intruders.
Often there is only one intruder at a time, but today it is a pair of males. Orpheus was preening on the platform and Ophelia was incubating when trespassers were seen high overhead. The mates immediately responded with a loud high-intensity alarm of Cheereek! Cheereek! Cheereek! as the trespassers entered the pair’s airspace. Refusing to leave, Orpheus chased the intruders to his invisible boundary and held firm. After a brief standoff, with all three ospreys hovering in a triangular formation, the unwelcomed pair left. Orpheus, still filled with adrenaline, flew to Ophelia and tried to lay his claim on her, but she would have no part of it. Now that she was incubating, she had no interest in mating.
Chasing dangerous predators and intruders away from the nest site is Orpheus’s responsibility and an important one. This nest is a lifetime investment for the pair and represents a significant investment of time and energy as the years go by. Orpheus does not bother with chasing crows, gulls, or other typical nest pests and saves his energies for more threatening violators such as Peregrine Falcons or Bald Eagles or other ospreys.
Hours later, we were startled by a markedly heated encounter. An osprey appeared nearby heading in the direction of the nest platform. As it entered the airspace, Ophelia sounded the guard alarm and Orpheus flew to the nest crying sharply. The pair continued to mount their defense by screaming with a particular shrill intensity at the intruder. Usually this is enough to dissuade a trespasser, but not this sleek white breasted-male. He continued to arc closer, as if coming down on a thermal. Orpheus made chase after the trespasser, screeching and pushing it away from Salt Point, inscribing circles around each far over the lake as their battle of nerves persisted. At one point, Orpheus even rammed the intruder with his wings, but did not hurt it. Finally, his opponent yielded and Orpheus flew back and proudly rested on the platform perch. At times the odds have been worse and Orpheus once drove off a gang of four intruders, but this particular contest was a real brawl.
The presence of so many intruders in the area, especially this late in the nesting season, is one more indication that we need more osprey platforms for these birds to safely nest upon.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#6
May 17, 2014
Ospreys must always be on the look out for danger. American and fish crows, blue jays, great blue herons, and gulls are notorious egg thieves as are raccoons, fox, skunks, snakes, and other climbing terrestrial predators. To prevent climbers from raiding nests, ospreys prefer nesting over water or extremely high up in trees, on utility poles and lighting towers, and on osprey nesting platforms. Many of you have noticed the piece of sheet metal encircling the osprey platform pole at Salt Point. This slippery surface serves as a very effective barrier, guarding against such climbers.
Nest cams have revealed that Intruding female ospreys can also pose a threat to a nest full of eggs. In dense breeding colonies with not enough safe nesting sites, an intruding female trolling for a nest site might attack an incubating female and break her eggs during the struggle.
In our area, bald eagles pose the most serious daytime threat to an osprey’s eggs and chicks. Eagles are prone to kleptoparasitism, stealing an osprey’s fish while in flight and have been known to kill them during heated chases. Eagles are perfectly capable of catching their own fish and a vast array of other prey items, as well as eating carrion, but they rarely pass up the opportunity to grab a fish from a passing osprey. When an eagle habitually bothers an osprey nest, making the parents chronically nervous, the clutch can fail from the overwhelming stress. Eagles may also drive ospreys off good foraging and nesting areas, or kill their young. Sometimes gulls or ravens try to pirate fish from ospreys, but rarely succeed.
There is a pair of Bald Eagles nesting on the west side of the lake near the Glenwood Pines Restaurant that occasionally come to inspect the Salt Point platform. I often see them at Salt Point during the fall and winter when the ospreys are no longer here, but they fly by in the summer as well. The eagles did not have a successful nest last summer, but remained in the area nonetheless. I saw a few brief encounters between Orpheus and one of these eagles, but there were no heated contests.
However, these eagles regularly hassle the nesting ospreys at the Treman Marina and Union Fields nests. The eagles purposely cruise by the osprey nests making the ospreys nervous. These flybys often result in chases as the ospreys try to distract the eagles from their nests. Usually the eagles gang-up on an osprey and sometimes it’s the other way around. It is hoped that by building a few more safe osprey platforms at the southern end of the lake, it will balance the situation. There is safety in numbers against eagles, and with a larger colony, the osprey will be less vulnerable and consequently the eagles will probably not bother the osprey as much. More ospreys in the south end of the lake will not impact the eagles, except that it may force them to do more of their own fishing.
Most predation on osprey chicks occurs at night. Great horned owls fly noiselessly in the dark, silently swooping in to take the chicks from the nest and sometimes kill the protective female in the process. This is the reason osprey prefer to nest in open areas away from tall trees where the owls can hide.
Osprey parents also vary in their responses to predators and disasters. Inexperienced and nervous pairs are particularly vulnerable to stress from predation, and sometimes spend too much of their time guarding the nest and not enough time fishing. Starved and stressed, their clutches fail and the pair may divorce. When a nest blows down during construction, the ospreys usually try again. If both a clutch and nest are lost to high winds, an established pair sometimes builds a new “frustration” nest. Although they will probably not replace the clutch, they will use the nest in successive years. Many ospreys without families simply wander for the remainder of the breeding season or leave early on their migration.
Established osprey nests built on safe platforms in the open have been known to last for decades—indeed, eyriesin Europe on rock pinnacles and small islands have been used for hundreds if not thousands of years. New, untested nests, on the other hand, are vulnerable to wind damage; every storm presents a threat.
Ideally, osprey platforms should have the usual six-inch deep nest box, to afford the nest and its precious contents greater protection from the elements. Studies find nests on platforms with out such a lip are more vulnerable to wind damage, suffering greater nest loss and clutch failures than typical nest box platform. The old Beacon Mills tower standing in the lake off of Cayuga is metal and has no lip around the top. Osprey nest here annually and are subjected to frequent wind damage and the occasional loss of nests.
The osprey platform at Salt Point, home of Ophelia and Orpheus and their latest brood-to-be, has an excellent design and superior location. The NYSEG crew who built the pole and nest box combined several available plans to make one that suited the site and needs of the osprey best. The nesting platform is deep, equipped with a diagonal perch, a screen to prevent eggs from falling through, and is situated atop on a sturdy 50 foot, non-electrified pole complete with a sheet metal predator guard. The pole was sunk into the bedrock at the western most end of Salt Point within several hundred feet of two good shallow fishing sources—Salmon Creek and the shelf off Cayuga Lake. There are no tall trees in the immediate vicinity for great horned owls to lurk in, and the nest has a 360° open view to protect against sudden attacks by eagles.
Last year, when her nestlings were only a few weeks old, a turkey vulture menacingly circled the nest repeatedly as Ophelia responded with intense alarm calls. Why did she get upset over a harmless carrion eater? To Ophelia, it looked like a very big threatening, black bird close to her nest and she could not afford to take the chance that it might be an eagle.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#5
May 1, 2014
Now for the birds and the bees part of our discussion on ospreys. Clear the room of young children, this is for mature audiences. During their courtship period, Osprey mate often, sometimes every half hour. On average, a pair in our area will copulate 60-90 times for every clutch of 2-4 eggs. Of these matings, only 39% usually result in successful cloacal contact, permitting fertilization. So many copulations for just a few eggs clearly indicates that much of the matings are for bonding—bringing the pair closer together—and not reproductive purposes. Between April 26-30, Ophelia and Orpheus mated at least 10 times a day, with most occurring in the morning hours.
Last year, was Orpheus’ first breeding season as a mature adult and he had a great deal to learn, especially about wooing and mating with his new partner. He was initially extremely awkward and comical, attempting to mount Ophelia backwards facing the opposite direction or sideways. Eventually he figured out the correct orientation and sired three healthy chicks. This year began more auspiciously with Orpheus now an experienced mate.
Most copulations take place when Orpheus returns from fishing or stick gathering, with Orpheus approaching Ophelia from the air and mounting her. On occasion Orpheus would make his intentions known by holding his wings slightly spread and held down with his tail depressed and slowly sidle over to Ophelia. With a quick flap of the wings, he would land on her back and mate.
During this last week in April, hormonal changes brought on by the pair’s courtship have caused Ophelia’s eggs to ripen. Now that Ophelia is in the peak of her fertility, their mating will serve to fertilize her eggs. Approachable and receptive, she assisted his advances by holding her body horizontal, drooping her wings, and pointing her tail up and to one side.
During this fertile period, Orpheus is especially attentive, closely guarding Ophelia to prevent other males from mating with her. Their mating frequency also sky-rocketed, especially in the mornings, up to 4-5 copulations per hour.
Sometime in the early morning of May 1, the three-week courtship of Orpheus and Ophelia came to an abrupt halt as Ophelia laid her first egg. Prior to this, she was usually found guarding the nest from the diagonal perch. Now, she’s sits deep in the nest incubating. Her behavior changes abruptly with the arrival of the first egg and she will no longer leave the nest unless Orpheus takes over incubating.
I was unable to see Ophelia lay her first egg due to stormy weather, but I did get to witness when her first egg came on May 6, 2013. Ever since, I have had great respect for chickens and all others that must release their eggs in this arduous fashion.
Early that morning, around 6:15 am, Ophelia began standing in the center of the nest and other than panting and fluffing her feathers out a bit, she stayed motionless for hours. Eventually, at 8:55 am her breathing got heavier and she began opening and closing her bill routinely. Ophelia held her tail slightly elevated and was in the throes of synchronous contractions as she depressed her rump. These parturition movements, caused as the egg travels down the oviduct, gathered in strength until she suddenly raised her rump and an egg exited the cloaca. Ophelia stood motionless in the “recovery phase” for a few minutes before snapping back. Egg laying seems similar to the birthing process and I will never take a carton of eggs for granted again.
Later, around noon, Orpheus delivered a fish to her, but Ophelia hesitated to fly with it to her favorite perch tree. After sitting with the fish for a few minutes, she took it to the nearby cottonwood tree, leaving Orpheus at the platform. Normally Orpheus would fly off, but this time he stayed perched. He preened for almost four minutes, stopping to look in the nest repeatedly, and then slowly made his way onto the nest. A sure sign of an egg. Unlike many species of birds, both male and female ospreys incubate the eggs and are equipped with brood patches, which are heavily vascularized areas of skin which lose their down feathers during the breeding season to allow the bird's body heat to transfer to the eggs.
There he sat until Ophelia glided in nineteen minutes later. He rose, carefully raising his wings, uncurled his talons, and lifted off the nest. Ophelia, who was on the perch, finished itching her head with her deadly sharp talons, curled them into a protective ball, and carefully walked onto the nest. She settled on the nest cup, lightly rocking to bring her egg into full contact with her brood patch to incubate it. The nest cup is so deep that the only time she is visible is when she raises her head.”
Like other young females, Ophelia, who is probably turning 4 years old, will lay a second egg, and possibly a third egg two to three days apart and should have a full clutch by May 6. Older females, which are able to lay earlier in the season can raise as many as four or five chicks if food is abundant, but younger birds such as Ophelia (probably going on 4 years old) have smaller clutches. After the long 5-6 weeks of incubation, we should be expecting chicks sometime in the beginning of June.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#4
April 29, 2014
Yesterday, I mentioned some of the weird things ospreys collect in their nests and talk about it in more detail in Family Life at Salt Point. While offerings of sticks, grass, or plastic babbles may be taken or not, gifts of fish are always appreciated without question. Orpheus has diligently fed Ophelia at least three large fish each day, usually juicy lake trout estimated at weighing well over a pound each,* proving to her that he will again provide for her and their future offspring.
Ospreys go for the first fish they can carry, which usually average 10–14 inches in length and weighing one-third to two-thirds of a pound in the Northeast although fish up to 2.5 pounds have been recorded. All of Cayuga's fish in this size class are fair game for the osprey including rainbow, brown, and lake trout, catfish, perch, pike, bass, carp, and sunfish.
Ospreys are well adapted as aerial hunters usually spotting their prey or their movements when they are 35–130 feet above the water, after which the osprey usually hovers before plunging feet first into the water. When it is rainy and windy, as it has been for much of April, Orpheus is especially diligent to ensure he makes his daily quota.
Watch this remarkable footage of osprey fishing to instantly appreciate the remarkable skills and adaptations of the amazing fish hawk. In another rather unusual video, an osprey swims to shore with a bass it cannot lift out of the water. While demonstrating Olympic-style strokes, this is not their normal fishing technique.
Throughout their courtship, Orpheus and Ophelia continue to learn how to communicate and work as a team. Each sky-dance, fish presentation, display above the nest, stick delivery, mating attempt, and challenge by intruders bolsters the pair's loyalty to each other and their nest.
Orpheus's meal presentations to Ophelia are accompanied with great fan fare, especially during infrequent moments of fair weather. He treats each one, be it a robust pike or tiny minnow, as if it was a prize catch! Like living in New Orleans, where anything can be an excuse for a parade, Orpheus makes a fuss of most of his catches. After diving and shaking the water off like a dog, he flies high above the platform, reveling in his hunting prowess. Announcing his triumph with a series of loud chirps--Peee-peee-peee! Peee-peee-peee! Orpheus dangles his fish for all to see. He gradually descends to Ophelia, placing his wiggling tribute at her talons.
Ophelia chirps and quickly accepts the offerings, which play a vital role in building the lifelong bond between her and Orpheus. The strength of this life-long bond will insure their future reproductive success—the production of healthy offspring prepared for the challenges of life.
Ospreys have a remarkably sensible system for dealing with evolutionary dead ends, giving females a way out of their partnership when necessary. If a female is not feed sufficiently by her mate during courtship or loses a clutch because of inadequate food, it signifies the male is in poor health or unable to provide for his family and the pair divorces.
Orpheus proved himself an excellent provider last year when the couple raised whopping three healthy chicks to fledging. Two chicks is the average number for an inexperienced osprey couple and three chicks is the sign of an excellent provider. Let's hope the pair can be as successful this season—taking advantage of every calm in between the storms.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
• I routinely retrieve fish dropped by the osprey to measure and weigh them. Fish weights are estimated based on standard length. There are a variety of fish weight calculators available on the web that allow you to approximate the weight of the fish. Some weight calculators have specific calculators for trout, bass, pike, and others are more general. The DEC offers a ruler-based version.
#3
April 28, 2014
News flash! Thirty-five years of research shows females are less predictable than males, a trend that applies across the animal kingdom from humans to birds. This British study found that males are much more consistent in their personalities day after day than females, who are more exploratory. Researchers conclude that females find predictability in their mates sexy, enabling them to plan for a future, and Orpheus and Ophelia fit their model well.
Throughout the spring and summer, Orpheus with some help from Ophelia will continue to make improvements to the nest replacing existing sticks and decorating it as they see fit. Orpheus routinely combs Salt Point and Myers Park for nest materials, dive-bombing the trees to break off sticks, picking up dead branches from the ground, or scooping driftwood from the water.
Osprey can be very exacting about their nesting materials as I describe in Family Life at Salt Point and may travel long distances to find the perfect addition to their decor. Orpheus has gone to great effort to collect nest materials to Ophelia’s liking, but she is just as likely to jettison these tributes from the platform as accept them.
But what might seem like whims to us are based in a long evolutionary history. Ophelia is accepting nest materials based on what her instincts and experience tell her she needs to create a safe environment for the forthcoming brood. As egg laying approaches, Ophelia needs to fill the holes between the twigs with softer nest lining materials, and Orpheus switches his “search image” from sticks to finer and flatter materials such as reeds, clumps of large sycamore leaves, and stems, which Ophelia works between the sticks. Willow whips are particularly good for weaving everything in place. Returning from her brief excursions off the nest, Ophelia often brings back clumps of moss, grass, bark, and leaves to line the nest.
As an “experiment,” I placed five piles of dried grasses and other plants from the shoreline on the gravel road below the platform and watched over as Orpheus gradually brought much of it to the nest one afternoon. Strong gusts of wind blew away whatever dried materials Ophelia had not had time to secure keeping Orpheus busy. Apparently, this pair of osprey shares my taste in nest lining. However, I do not want to tempt them by testing their propensity for collecting human debris, especially dangerous items.
Ospreys have a deserved reputation for being pack rats and are notorious for collecting bizarre items in their nests. Just Google “Osprey Cams” or view my favorites sponsored by Cornell University and Audubon to see the variety of “treasures” or “nestorations" added to osprey nests. Most adornments are of natural origin, such as clumps of moss and bright green algae, birch bark peelings, shells, and animal bones, while other treasures are straight from the landfills, including bizarre items like adult magazines, naked Barbie dolls, and bikini tops.
Sadly, hazardous entanglement materials like nets, plastic string and fencing, Mylar string and balloons, and discarded fishing line and tackle end up in osprey nests as well, causing strangulated limbs, starvation, and death. Baling twine, now made of polypropylene rope, is especially attractive and potentially dangerous to osprey and other birds, presenting an increasing problem in agricultural areas. University of Montana researchers estimate that 10% of osprey chicks die in their nests after getting tangled in baling twine. Adults also get maimed and strangled. Baling twine was found in nearly every nest with one nest containing more than a quarter of a mile of baling twine!
Devotees of the osprey nest cams were deeply disturbed when a ball of deadly baling twine appeared in the nest of Ozzie and Harriet at the Dunrovin Ranch cam in Montana earlier this week. Two days ago, much to the relief of viewers worldwide, Harriet showed the good sense to pitch the hazardous rope out of her nest. Last year, fishing line was spotted dangling from Ophelia’s nest, but thankfully it too was ejected before anyone was hurt.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
#2
April 27, 2014
Many of us had doubts that spring would ever come this year and on late April days like this, when it’s plummeted from 60 to 30 degrees Fahrenheit and flurrying, the jury is still out. But spring has come to Salt Point, Lansing, as the willow buds explode, rainbow trout run, insects hatch, and the birds return. Despite the inclement weather, the ospreys of Salt Point, nicknamed Orpheus and Ophelia, are busy tending to their nest and each other. They reunited at the nest on April 5, quickly renewing their courtship with Orpheus sealing the deal by giving Ophelia a two-pound headless carp.
Just over three weeks later, their relationship is secure. Unlike last year when they first met on Earth Day, April 22, Orpheus and Ophelia already had a committed relationship at the start of this breeding season. The pair has spent these weeks sprucing up last year's nest with twigs Orpheus breaks off trees on the fly, augmented with grasses and other nest lining, which both birds collect. These bonding moments allow the pair to reacquaint themselves with each other after their winter hiatus. Ophelia and Orpheus got an earlier start breeding this year compared to last year when they had to build a nest from scratch. It is interesting to note the behavioral differences exhibited by the pair as newly mated birds in 2013 compared with their actions as established mates in 2014.
Ophelia spends the majority of her time on the platform or nest, fiercely guarding it from potential takeovers from marauding ospreys looking for homes and mates. Shrieking “cheeeerp” alarm calls are her first line of defense. If the intruder persists, Ophelia’s escalating cries usually bring Orpheus in a high-speed dive aimed directly at the offender. Orpheus expertly drives away intruders—up to 5 ospreys at a time. Intruders sometimes give up right away, but more often Orpheus duels with them by flying seemingly choreographed circles, figure eights, and daisy-chain battle formations in the air with Orpheus always on the offensive. In especially heated pursuits, Orpheus may ram a contender with his wings as they speed by each other, Orpheus has always returned to Ophelia victorious.
Twice this season Ophelia left the empty nest unguarded long enough for an intruding female osprey to claim this precious real estate. Ophelia, never very far away, retaliated with lightening speed by plunging directly at the intruder, audibly scraping the intruder's backs with her talons, knocking the intruder out of the nest.
During the first flirtatious weeks of the 2014 osprey season, Orpheus and Ophelia could be seen circling and chasing each other around Salt Point, playfully enticing one another to the nest and often culminating in mating. Unlike last season, this year’s earlier arrival in April and existing nest afforded the couple time to spend hours leisurely sitting side-by-side and occasionally napping on their favorite bare cottonwood branch.
Lucky viewers willing to brave the cold afternoon winds on April 5 saw Orpheus perform a sky-dance or “fish-flight” with a 2-foot stick followed a second dance the next afternoon with a foot-long lake trout. The wind was unforgiving, making it impossible to hover in one place and muffling his mating cries. Orpheus performed a more traditional sky-dance last year on a more temperate April 22, which I recorded in my notes as follows:
“April 22, 2013: aftertwo and a half days of heated contests with intruders Orpheus saw Ophelia near the platform for the first time, grabbed a stick, and did a spectacular sky-dance over the platform using a stick for her benefit. He noisily flew up 500-600 feet over the nest platform while crying a high-pitched, attention-getting ”eeet-eeet-eeet” and dangling his long, bright white outstretched legs, proudly displaying a three-foot long stick in his talons. He presented a fine figure with his wings and limbs stretched to their fullest. He suddenly began fluttering his wings and calling loudly, undulating slightly up and down while hovering. Losing altitude he stops again after about 50 feet or so to hover again, showing off the fish, calling out, and making a fuss. He continued descending slowly to the nest in this way stopping like an elevator at every floor until finally placing the stick in the new nest with much fan fair. Ophelia flew over to inspect the stick and sat next to it in an act of approval. After sitting on the nest for nearly a half hour, she began to cry out, begging for food. Orpheus responded in short order with a decent 14-inch lake trout and by doing so, cemented their pair bond. Ophelia allowed Orpheus to court her and the rest, as they say, is history.”
Orpheus has been courting Ophelia this spring, bringing her fish and twigs to rearrange, and mating with her whenever possible. The way to a female osprey’s heart is literally through her stomach via “courtship feeding,” where prior to laying females are fed almost exclusively by their mates. Once Ophelia lays, she and her future brood are totally dependent on Orpheus for food until the chicks fledge.
When ospreys first arrive at the nest their gonads are only partially developed. The high-dose diet of nutritious fish provided by courtship feeding kick-starts Ophelia’s estrogen production, bringing her into breeding condition. By the time courtship is over and she is ready to lay, her ovaries and eggs have matured and her eggs fully enlarged. Courtship feeding also stimulates Orpheus’ gonads to mature in synchrony with Ophelia’s and cements their bond. Rising hormonal levels create dramatic behavioral changes in both birds, stimulating Orpheus to attempt copulations frequently. Ophelia loses her urge to fish as her desire to nest increases along with her receptivity to Orpheus’ sexual advances.
Young male ospreys must learn to be attentive to their mates and families and share their catches with them, behaviors that contradict their lone lifestyle during the winter season. Each successive year the couple is together, the male usually learns to share more readily with his mate and the pair learns to cooperate more efficiently. Learning to share one’s hard-earned fish is more difficult for some individuals than others, although the adaptive value of courtship feeding is clearly in the male’s favor. Orpheus demonstrated his adaptability last year when he quickly transformed from a carefree bachelor into a committed partner and father. Except for a few early feedings this year, where he was slow on delivering Ophelia’s portion, Orpheus has again been a readily conscientious mate. Perhaps he is catching on to the first rule of "Happy Osprey Relationships": Keep the female well-fed and satisfied and in turn, the male will be assured of his mate’s fidelity and affections with insurance on any offspring’s parentage. It is clear that content, satiated females are more sexually receptive and less likely to solicit food and sneak copulations from passing strangers. I have not observed these behaviors at Salt Point, as they tend to be more common in densely populated osprey colonies
Blustery winds and stormy weather this spring seems to put a damper on both Orpheus’ fishing and his love life. Despite their exceptional eyesight, at least twice as good as ours, ospreys cannot see their prey or traces of them when the water’s surface is broken by rain, strong winds, or choppy waves or it’s muddy. Each cold, stormy day that passes represents lost fishing and romantic opportunities. Orpheus’ techniques in the Don Juan category have vastly improved since last year (when he did not quite know “which end was up”). Orpheus still has trouble combating the strong wind at Salt Point and has been blown off Ophelia’s back repeatedly during amorous overtures. And yet, like postal workers, neither snow nor rain nor heat keeps Orpheus from his appointed rounds. In the last few days, the frequency of their mating and the number of apparent successful copulations or “cloacal kisses” have markedly increased, an indicator that Ophelia is readying to lay eggs.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
Please note: Fish measurements are estimates based on standard length.
#1
April 5, 2014
[This blog is about the family life of two ospreys, nicknamed Orpheus and Ophelia, nesting at Salt Point in Lansing, across Salmon Creek from Myers Park. The first three paragraphs are based on fact, but written with a little imagination in the mix. The rest of the text in this installment and all further installments of On Osprey Time are factual and based on observations unless otherwise noted.]
Orpheus follows the glistening creek below as he glides effortlessly. At last the valley opens and he sees the lake in the distance, shining like a slender finger beckoning him home. A thermal whisks him past South Hill and over the city below with the bustle of Route 13 still apparent from 800 feet up. The lake below glows in the late day sun. A hint of the recent snowmelt is in the air as are the sounds and smells of waterfalls and swollen creeks, all rushing toward Cayuga and welcoming him home. Circling the Cornell Campus below, he heads to Beebe Lake and then swoops down Fall Creek gorge to the lake. He flaps and glides until he sees his next updraft over Route 13. Following it up the hill, Orpheus joins the kettle forming near the malls. Entering low he wheels upward with the other hawks, riding the wind. The heat from the parking lot and roofs sends more and more air up and soon he is above the first layer of clouds.
Continuing northwest, Orpheus glides for several miles up the lakeshore. The breezes are with him and the flying easy. Passing rushing waterfall after waterfall, familiar landmarks from his first summer flooded back to his memory, and were spreading out like a map below him. He knows this place—its sights, sounds, and smells—this is the lake where he was born and now he was back for the second time. The lively blue waters, rolling valleys, and steep hills were imprinted in his brain forever. And like hundreds of thousands of osprey generations before him, Orpheus had returned to the place of his birth.
The lake cliffs race by as Orpheus glides north on the wind blowing up the lake. The currents lift him like when they hit the steep hillsides bordering the lake. His progress is swift; he is almost home. The sound of muddy spring melt waters rushing to the lake excites something in him, as did the familiar road hugging the shoreline. Within a few minutes he comes to a rounded point of land jutting into the lake, about ten miles north off Ithaca. Orpheus lowered his altitude as he recognizes the steep sloping hill, winding road down to the lakeshore, and finally sees his nest platform on the western tip of Salt Point much as he had left it last year.
Orpheus settles on nest platform’s diagonal perch and lets his muscles relax. At last he is home and his travels at an end. For the first time in months, he does not feel an overwhelming restless need to fly, to hurry. He had made it. He had beaten the odds and flown somewhere between 4,000-8,000 miles from Lansing to his winter home in Central or South America and back twice and arriving safely home. Although ospreys can live as long as 25 years, they seldom do. In New England, young ospreys have 37 percent chance of living to their fourth year, but their survivorship improves after significantly after that.
A sudden urge (or surge of hormones) inspires Orpheus to fly by a near cottonwood, snap off a two-foot stick as he flew past, and shoot up into the air, performing the famous osprey sky-dance or “fish-flight.” The northwest wind is against him and unforgiving, making it impossible for Orpheus to hover in one place. Despite crying out as loud as he could, his usually piercing screams are barely audible to human ears.
Unfortunately Orpheus’ rest is short-lived as about ten minutes later an intruding osprey circles above the point a little too close to the platform for comfort. Orpheus came out from nowhere, shooting after the intruder like a bullet and chasing it away from the nest and over the lake. They flew in great circles and zigzags as the intruder repeatedly tried to get a closer look at the nest and Orpheus kept blocking him and driving him away. Challengers continued to approach the nest in groups of one to three ospreys for a few more hours until the colder winds finally brought Orpheus peace and time for an evening catch.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point
Lansing, NY
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