Blog # 474 Not an Empty Nest
With the fledglings flying about, the nest looks empty, and it is most of the day. However, the nest is still a noisy family meeting place for meals and a refuge for sleeping fledglings. The siblings’ days are spent practicing important survival and life skills derived from combinations of instinctive (nature) and learned (nurture) behaviors.
Ursula takes it easy in the shade of the cottonwoods as she is no longer needed by her family. She’s begun feeding herself to make up for the weight she lost over the breeding season and visits the nest at mealtime happy to nibble at a fish. After she has regained her strength, she will migrate to her wintering spot somewhere in South America, dodging hurricanes along the way.
At noon today, Ursula went to the nest calling for food. She was joined by fledglings O’Connor, O’Leary and O’Shea in an ear-piercing chorus of begging that probably travelled for miles encouraging Orpheus to hunt. It took Orpheus about 20 minutes to respond with a fat 9–12-inch white sucker. O’Leary and O’Shea uncharacteristically shared the fish while Ursula stood by. One of the fledglings would have flown away with the fish had it not been so heavy.
The young play about in the air before dipping their feet at objects underwater. If Orpheus continues to feed them regularly, what will motivate these fledglings to learn on their own?
Perhaps their captivation for hunting, the pull to fly low over the surface dragging their talons to get a feel for this unique medium. Fishing is instinctual but soon becomes their obsession. The hunt is in their blood, in every cell of their being, just like flying into the wind. You can’t hold them down. At first, they perch by the water, watching the water and everything living in it, and developing appropriate search images for the fish. They learn to recognize in a split second what fish look like in both clear and muddy water. Fascinated by their movements, the young bird must yearn to play with them or make a catch.
It is thought that fledglings raised together learn faster by modeling each other than those raised as singletons. Sibling nestmates do exhibit similar foraging techniques and have greater success over time relative to singleton birds. However, Ospreys raised in isolation are very capable of fishing without any instruction.
O’Leary flying over the lake, perhaps looking for fish, courtesy of Cindy Sedlacek.
Nothing is keeping O’Connor, O’Leary and O’Shea from the water. Floating sticks and other objects become targets as the siblings practice swooping down from a perch, snatching them up. This behavior develops into the plunge-dive, the easier of the two fishing methods used by Ospreys. When a raptor perched near the water sees a fish, it will drop to the water feet first, grab its target fish, and fly off with the fish in tow. Minnows are an easy catch for the young, but they don’t offer much nutrition, underscoring the importance of Orpheus feeding his offspring during this period.
O’Shea about to dip her feet in the water at Salt Point, courtesy of Cindy Sedlacek.
These days, Orpheus brings 5–6 fish a day to the nest for O’Connor, O’Leary and O’Shea to split and will continue feeding them until they are self-sufficient. However, in a few weeks Orpheus may cut back the number of fish he delivers to encourage the young to become independent.
The other fishing method, the elegant Osprey hover dive, comprised of an intricate series of complex behaviors, is a vital technique for the young to learn especially for marine fishing, but it will take them months to perfect it. Meanwhile, the less energy intensive yet less accurate sitting plunge-dive hunting method will suffice and be their key to independence in September.
There are many nuances to Osprey fishing using both innate and learned behaviors: the young must integrate information such as sun glare, water clarity, wind direction, current, and the incidence of light into their dive as it tracks the moving prey. Fledgling awkwardness is evident as they attempt this complicated series of behaviors, but they quickly gain skill. The competent fledgling, able to feed itself, has no need for supplemental feedings and stays away from the nest, letting Orpheus off the hook, so to speak.
As with flying, Orpheus does not instruct his offspring how to fish, but guides them to his favored fishing spots at the best times to hit them. Orpheus does a large percentage of his fishing in the early morning or late afternoon when the sun is low on the horizon lessening the glare off the water. Cayuga’s many shallow coves offer calm, secluded waters good for yellow perch and sunfish, and its tributaries like Salmon Creek are good for brown bullheads and suckers. The best place to fish on calm days is over the shallow shelf that extends off Salt Point. On stormy days, Salmon Creek provides more sheltered fishing. Orpheus has an uncanny ability to catch bullheads in Salmon Creek after a storm has turned it into a rushing opaque, muddy river. Presumably he strikes when he detects their slightest motions in the swirling mud. Hunting techniques like Orpheus’ can only be learned through observation and experimentation.
Eyes to the sky!
Candace
Candace E. Cornell
Salt Point Natural Area
Cayuga Lake Osprey Network
Guest photographer:
Ithaca’s Cindy Sedlacek brilliantly depicts the Ospreys of Cayuga Lake with the intimacy of a true bird lover. Enamored by the animal’s gorgeous wings and graceful flight, her work is a tribute to the power and grace of these stunning raptors.
O’Connor resting on the shore Cayuga Lake, courtesy of Cindy Sedlacek.
EYES ON OSPREYS
WATCH!
Salt Point Osprey Cam 2024 LIVE!
Salt Point Osprey Nest Cam 2019-23
READ!
On Osprey Time: a blog about all things Osprey
VISIT!
Cayuga Lake Osprey Trail Nests Driving Tour
Complete Cayuga Lake Osprey Trail
HELP PROTECT OSPREYS:
• Stay 100-300 feet away from Osprey nests during the breeding season.
If the Osprey vocalizes or flies off the nest you are too close!
BACK OFF IMMEDIATELY.
• Carry binoculars to view wildlife from afar.
• Dispose of used fishing lines, twine, nets, and plastics which
can kill Ospreys and other animals of the lakeshore.
• Become a nest monitor for the Cayuga Osprey Network: cec222@gmail.com.
• Find an injured animal? Call the Swanson Center at 607-253-3060.
The Janet L. Swanson Wildlife Health Center, an annex of the Cornell University Hospital for Animals, is a veterinary hospital dedicated solely to the treatment of ill or injured native wild animals. They provide expert medical and surgical care for over 1,000 patients annually, from locally and across the state of New York, with the goal of releasing them back to the wild. The Wildlife Health Center operates within Cornell University, a registered nonprofit, and relies largely on public donations.
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