Adult Osprey in Nest 2024
It’s that time of year! New Hampshire’s snowy cold winter is coming to a close, and with that the arrival of our resident ospreys draws near. In the fall, the male and female ospreys of a mated pair migrate to different locations, and expend a significant amount of energy flying thousands of miles over large bodies of water to reach warmer climates in Central and South America. They’ll spend the next few months feeding on plentiful populations of fish, and building up energy to make the long trek home. Ospreys rely on their keen sense of sight when hunting for fish, and are able to spot one from up to 100 feet in the air! One of the main reasons for migration is the availability of food resources. When frigid and icy conditions roll in during winter months at Great Bay, visibility drops along the surfaces of the many lakes, estuaries and rivers, and would greatly inhibit an Osprey’s ability to hunt for fish. An ospreys diet is 99% fish, to avoid starvation and harsh weather, travelling south is a crucial survival strategy.
Ospreys return to the shores of Great Bay in early springtime. Mated pairs will return to the same nest each year, travelling thousands of miles and often arriving within days of each other. As daylight increases in late winter and early spring, hormones are activated within the birds that cause a response to migrate back north. For at least five years a banded pair of ospreys have returned to the nest viewable from our boardwalk trail and live streamed from our osprey camera. Last year the banded female osprey arrived on March 26th, and the banded male osprey arrived four days later on March 30th. On March 24th of this year New Hampshire Audubon reported sightings of an osprey in Hinsdale, and another one in Nashua. Tune in to our live cam for a chance to watch one of these majestic birds arrive at Osprey Cam – The Great Bay National Estuarine Research Reserve (GBNERR) and check back here for Osprey updates as the season progresses!
Interested in rare bird sightings? Follow New Hampshire Audubons Rare Bird Alert!
This is New Hampshire Audubon’s Rare Bird Alert for Monday, March 24, 2025 – NH Audubon
Banded Male Osprey Bringing Stick to Nest 2025
April 11th, 2025 Update:
Both the male and female banded osprey returned ten days ago on April 1st, within an hour of each other. The banded male landed on the nest at 5:49 pm and the banded female landed at approximately 6:30 pm.
Since arriving, these powerful birds have been working around the clock to prepare their nest for chicks this season. Osprey nests are constructed on trees, cliffs, telephone poles, and other tall structures. Ospreys will often seek out nesting locations close to a body of water; this allows easy access to fish and limits their time off the nest when caring for their young. The nest, viewable from our Osprey Live Camera, is built on a wooden platform and is estimated to be between 5 and 6 feet wide. Nesting materials include large sticks, saltmarsh grasses, mosses, seaweed and even occasional litter. The male will use his strong talons to carry clumps of softer grasses and plants to line the bottom of the nest creating a cozy “crib” for their chicks. He’ll place larger sticks and branches along the edges of the nest to build up the sides creating a barrier protecting the osprey chicks from falling out. The female osprey will arrange and move materials around, using her beak and talons to scratch and shift the nest until satisfied.
Challenges osprey face while building their nest can be weather related. If rainy and windy conditions are unrelenting it can be difficult for osprey to adequately prepare their nest. Competition with other ospreys is another challenge. Currently, there is a rogue female osprey vying for a spot on the monitored nest. She has been persistent in her effort to establish herself as a new resident, stealing fish from the banded male osprey, perching on the nest and calling continuously. We are hopeful that the banded pair will be able to defend their nest and solidify their spot on Great Bay.
Typically, the female osprey will lay her first egg around two weeks after returning to the nest. Last year the banded female osprey laid her first egg on April 12th, her second on April 15th and her third on April 18th. Following that same pattern, we can hopefully expect the first egg laid within the next week or two.
Banded Male Osprey with Rogue Female on Nest 2025
May 2nd, 2025 Update:
At around 6:00 pm on Saturday, April 26th the banded female osprey laid her first egg of the 2025 season. Three days later on Tuesday, April 29th, she laid her second egg at approximately 8:00 in the evening. Female ospreys generally lay between two and four eggs each season. This banded female has consistently laid three eggs for the past several seasons, so we expect a third egg to be laid in the coming days. Like other birds, ospreys incubate their eggs to keep them warm and safe from predators. Male and female ospreys will take turns sitting on the nest. Female ospreys occupy the majority of incubation time and are occasionally relieved by the male osprey to hunt. Osprey eggs begin hatching after around 38 days, typically in the order they were laid. These creamy white eggs are mottled with brown and red specks, providing camouflage from many predators such as raccoons, snakes, and even other birds of prey like great horned owls and bald eagles. Bird eggs, including osprey eggs, are a valuable source of protein and healthy fats making them an extremely desirable food source.
The usage of chemical pesticides from the 1950s-1970s posed a significant threat to ospreys. DDT (dichlorodiphenyltrichloroethane) is an insecticide developed to prevent insect damage in agriculture and curb pest-spread diseases. During heavy rains, runoff from farms and lawns would carry DDT into neighboring waterways where it would accumulate in fish and aquatic organisms. Biomagnification is the term used to describe the way pollutants like DDT move throughout an ecosystem. As DDT moves up through a food chain it becomes increasingly concentrated, this results in animals at the top of the food chain, like ospreys, having a much higher level of DDT in their system than smaller fish in the same ecosystem. DDT was not directly responsible for killing adult osprey, this compound interfered with their calcium metabolism and intestinal binding activity causing eggs to be laid with such fragile shells that they were unable to support the weight of adult birds during incubation and the eggs would be crushed. DDT was banned in the United States in 1972, since then ospreys have steadily increased in population and eggs (like the ones laid by the banded female osprey this year) can be safely incubated before hatching!
Banded Female Osprey with Two Eggs on the Nest May 2nd, 2025
