At the Museum This Month: Ospreys

Since 2002, island resident and H.L. Ferguson Museum Board member Kenneth (Ken) Edwards has been recording the spring arrival of the ospreys to Fishers Island, including their nesting sites and the number of pairs each season that migrate north from as far away as South America.

Master birder Ken Edwards, Sr. on his annual osprey count. Credit: Todd McCormack

The first of the “fish hawks” usually arrive close to St. Patrick’s Day, March 17, give or take a few days. The males arrive a day or up to a week ahead of the females. This season, Jim Reid and Genie Trevor spotted an osprey flying over West Harbor on March 20 and Edwards was the first to spot an osprey on a nest on March 21, the site between Dock Beach and the Three Sisters.

Starting in 2005, with help from the Fishers Island Utility Company and their bucket truck, Edwards added a fledgling count to his record keeping, tracking the number of young born to each pair of ospreys on the island. The advent of drone technology (along with several eager volunteers) has made the process much simpler and Edwards is able to zoom in on each nest to get a head count even for those sites that the bucket truck wasn’t previously able to reach. You can spot the nests around the island, built of sticks resting high atop telephone poles.

Two osprey chicks in the nest at Four Corners. By Todd McCormack

The ospreys lay their eggs around May 1 and the chicks hatch after a 30-day incubation period. The adults remain busy fishing and bringing fish back to the nests and by mid-July, around six weeks after they hatch, fledglings can be seen at the edge of the nests, beginning to flap their wings.

The big event is the flying lessons that typically begin in early August. To encourage their young to take the proverbial leap, an adult osprey will drop a fish up to 50 feet away from the nest, forcing their young out for food. Once they learn to fly, they then have to learn to fish. “There are a lot of misses but eventually they get the hang of it,” says Edwards. “Once their young are able to fish, the parents start migrating south.” Male ospreys leave first, followed by the females.

Adult osprey in flight. By Mary P. Murphy

The young ospreys stick around into September and even October before heading south. They won’t be back up north for another three years; when they return, they’ll court for a mate and compete for one of the 26 nesting sites on Fishers Island.

The most successful year of the past 18 years since Edwards began keeping records was 2020, with 42 young born to pairs occupying 21 different sites around the island. Previous to that the best year was 2018, with 34 young on 17 nesting sites.

The late Ed Horning reported in his 1999 account of increasing and decreasing birds on Fishers Island that “the first record of a nest was in 1946, in 1961, there were six nests, in 1991, seven.

Ospreys are amazing birds to watch as they hover on the winds and then dive straight down into the water to (hopefully) come up with fish. Be sure to watch the nests this summer as the fledglings begin to flap their wings and make their maiden flights.

Did you know?

To get up close and personal with one pair of the island’s ospreys, you can watch the Museum’s Osprey Cam that is focused on the nest located at the east end of Middle Farms. Follow the osprey cycle from spring arrival to chick hatchings, mealtime and fledgling flights.

Osprey Cam screenshot captured by Richard Marshall on April 10, 2021

2020 Fledgling Report

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