Blog #427 How to Enjoy Osprey Watching
Orpheus flying in the snow at Salt Point, courtesy of Cindy Sedlacek.
Many of the breeding Ospreys have returned to their nests in the Cayuga Lake Basin, although a few mates and pairs are still on their way north. In general, the older breeding males arrive first followed by their mates. After that wave, unmated adults called floaters or intruders and second year birds, migrating north for the first time, will join them to fill in empty nests and replace lost mates.
To get the greatest enjoyment watching an Osprey family, learn about their life
history and the stages they go through during their breeding season. This is simple as they nest in the open and are large enough to observe from a respectful distance of 300 feet. Find a nest you would like to observe from the Cayuga Lake Osprey Trail and plan to visit it at least once a week if not more and record the important events listed below. Once the chicks hatch, they mature before your eyes.
I. Arrival at the Nest
[Salt Point Update: Orpheus arrived at the Salt Point March 28. Ursula, on April 8.]
Once a pair has claimed the nest, they will be busy fetching sticks and other nesting materials to repair their nest from winter damage. If you see a pair sitting together,
Male carrying a fish for his family, courtesy of Cindy Sedlacek.
Ursula with her heavy necklace at Salt Point, courtesy of Cindy Sedlacek.
compare the size of the two birds. Females are 25% larger than their male mates and sport a brown “necklace” on their chests. The necklace varies from faint and narrow to broad and dark. Adult males have a pure white breast, but sometimes have a faint breast marking. As the season progresses, the adult male’s feathers will turn darker from a buildup of waterproofing preen oil. The adult female’s feathers bleach in the sun after a season on the nest.
II. Nesting and Courtship
[Salt Point Update: Courtship Began April 8]
Male carrying stick for his nest, courtesy of Andy Morffew.
Established pairs use the same nest, repairing it continually, for life. New pairs may take over abandoned nests or start new ones on sturdy substrates. Both mates collect nesting material. The male gets the bulk of branches and heavy sticks while the female collects the delicate moss and muddy grasses for the egg cup. The male will continue to add to the nest all season. Males have an interesting way of shaping the nest cup. I call it the “snow angel.” The male lies on his belly and kicks his legs and nesting material backward toward the nest rim, reminiscent of a snow angel. Osprey nest that has grown over years can weigh in excess of 500 lbs.
Osprey pair about to mate, courtesy of Cindy Sedlacek.
Courtship begins as soon as the mating pair reunites or a new pair bond is formed. The definitive way to distinguish male from female is to watch their pair bonding. In successful copulations, the male mounts the female while she pulls her tail to the side and bows her head. Frequent mating during the next 14 days serve to bring the female hormones up to levels that allow successful breeding. It is only the last few copulations that fertilize the eggs.
When you watch courting Ospreys, you will see more than just repetitious mating. The male is attentive to the female bringing her ample fish. The pair will sit side by side in the trees quietly vocalizing or fly in formations, looping, circling, and in tandem flight. With the female on the nest, the male may perform his sky dance—an aerial ballet performed with a stick, fish, or empty talons. The male will fly a few hundred feet up, hover while calling out, and suddenly drop 50 or so feet. Here he hovers, cries out, and suddenly dips again repeatedly until he reaches the nest and presents his prize to his mate.
III. Incubation
(Salt Point eggs will probably lay April 22, 24, and 26, assuming the usual 3 eggs)
Females will lay 1–4 eggs, laying one every 1–2 days. Laying usually takes place in the morning. After laying, incubation starts. Look for the adults taking turns sitting low in the nest incubating eggs. Some males have little to do with incubating, but Orpheus is a real hands-on dad. Sometimes he even pushes Ursula off the nest. Much of the time it will look like the next is empty but it is not. The incubation period can last 35–43 days, with the female doing the heavy lifting through sun, wind, rain, snow, hail, and rain. (Mothers are the heroes of our story.)
Female Osprey tending eggs in the snow, courtesy of Cindy Sedlacek.
IV.Hatching
[Salt Point Update: Hatching Begins May 13-20]
Chicks hatch 35–43 days after incubation begins. Look for the male bringing food to the nest and making "head bows" into the nest center. The male and female often have a tug of war over the fish when he first arrives at the nest and sometimes insists on feeding the youngsters himself. Typically, the female grabs the fish and feeds her chicks one at a time, usually with the loudest one getting fed first. Chicks typically can't be seen until they are 2–3 weeks old, making mealtime the best time to view them. Chicks feed eagerly and noisily. Hatchlings are able to walk to the rim of the nest to defecate.
V. Nestling Count
[Salt Point Update: Hatch date plus a month]
month-old nestlings poking their heads above the nest rim, courtesy of Andy Morffew.
Approximately 4 weeks after hatching, look for the heads of chicks to show over the rim of the nest, particularly at mealtime when adults bring food to the nest. The young ones chirp to welcome their father as he cries out to them on his approach. At other times they lie flat and are harder to see. Count the number of chicks in the nest before they learn to fly.
VI Fledgling Count
[Salt Point Update: Fledge Count is Hatch date plus 1-2 months]
Chicks begin flying when they are 7–8 weeks old, and are still fed by the adults. This is one of the most enjoyable stages as the young birds prefect their skills. Count Ospreys are the bell weather of the lake and tell us when the water chemistry is off balance. These fish eaters are top predators and vital for the lake’s ecology.
Mother feeding her month-old chick, courtesy of Andy Morffew.
these lively fledglings the number of chicks who have successfully fledged the nest and are
The fledges spend about a month learning to fish, although some youngsters are quicker studies. Once they can fish, they are ready for the adventure of their lives—their first solo migration to South America. Note when the parents and fledges leave on migration.
Congratulations! You’ve monitored a nest. Ospreys are the bell weather of the lake and tell us when the water chemistry is off balance. These fish eaters are top predators and vital for the lake’s ecology. Citizen scientists nest monitors can help us keep tallies on the bird populations and calculate breeding statistics by tracking the following:
Date of pair arrival
Date of egg laying signified by the female not leaving the nest until the male broods
Number of nestlings
Number of fledglings
Date of first chick fledging.
Date chicks were last observed at the nest
Become a Cayuga Lake Osprey Network nest monitor. Contact cec222@gmail.com. Thank you.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of Salt Point, Lansing, NY
Cayuga Lake Osprey Network
Guest Photographer:
Cynthia Sedlacek, musician and Director of Data Administration and Reporting at Cornell University, is a surprising artistic talent. Cynthia’s affection and admiration for raptors are evident in her exciting photographs primarily of Ospreys nesting around Cayuga Lake and the red-tailed hawks of the Cornell Campus. Her photographs of local Ospreys are incomparable as she captures their essence, their jizz, and their inner bird. From the hard-to-see nestlings to the fast-flying adults, Cindy goes beyond the pale to catch all aspects of Osprey life in the Cayuga Basin. “My camera allows me to capture their beauty in many ways that the human eye can’t see,” she says, “like their spectacular wing positions and detailed feather patterns.” Cindy and her husband Karel are also avid nest monitors for the Cayuga Lake Osprey Network and video stream footage of the campus hawks.
EYES TO THE SKY!
WATCH!
READ!
On Osprey Time: Ospreys of the Finger Lakes
VISIT!
Cayuga Lake Osprey Trail Nests Driving Tour
Complete Cayuga Lake Osprey Trail
HELP PROTECT OSPREYS:
•Stay 300 feet away from nests during the breeding season.
If the Osprey vocalizes, you are too close!
Back off Immediately.
•Carry binoculars to view wildlife from afar.
•Help keep local waters clean, healthy, and safe.
•Recycle used fishing lines, twine, and nets, which can kill Osprey.
•Join the Cayuga Osprey Network and volunteer to help monitor Osprey nests: cec222@gmail.com.
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