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Northern Virginia’s ospreys are showing signs of strain after missing chicks, a nestling death and multiple rescues marred this year’s breeding season.

The brown-and-white raptors, which stand about 22 inches tall and have wingspans reaching 65 inches, typically return in March to nest near open water. Their young usually leave the nest in July, before the birds depart the region by late August.

Along the Potomac and Occoquan rivers, ospreys build large, tangled nests in trees and on platforms, poles, duck blinds and channel markers. They hunt by plunging feet first into the water, seizing fish with sharp talons and carrying the catch back to feed their chicks.

Mixed Fortunes at Local Nests

A pair has raised young for years on a platform at Belle Haven Marina, on the northern edge of Dyke Marsh. The birds produced two chicks this year, but one died around the end of June.

Larry Cartwright, who has conducted a breeding-bird survey at Dyke Marsh since 1994, found the surviving chick eating on June 30 but looking slightly underdeveloped and showing little movement afterward.

By July 6, however, the chick appeared more active. Cartwright saw it stand and flap its wings for the first time, raising hopes that it would leave the nest within two weeks.

The season has been more successful near the Porto Vecchio condominiums beside Hunting Cove, where ospreys have nested on two platforms for more than a decade. All five chicks born there this spring—three in the northeast nest and two in the southeast nest—are now flying.

Their survival required human help. Residents rescued two chicks this year, including one that fell from its nest and another with twine wrapped around a wing. Two residents also freed a chick tangled in fishing line last summer, and ospreys from the nests have died from fishing-line entanglements on at least two previous occasions.

Elsewhere, the outcomes remain uncertain. Jay Spiegel, who operates a camera at an osprey nest behind his Little Hunting Creek home, reported that two chicks disappeared around June 23. Their fate is unknown.

An osprey was also seen several times this year at a nest atop a light pole over Walt Whitman Middle School’s softball field, but observers did not confirm any chicks there.

Food, Weather and Development Add Pressure

Final surveys are still needed before experts can assess the full breeding season, but several possible stressors have emerged.

Local specialists point to this spring’s weak Potomac River shad run, warming water that can alter fish-migration timing, severe cold and heat during the hatchling stage, shrinking breeding habitat, competition from growing eagle populations and increasingly intense storms.

Concern extends beyond Northern Virginia. A May 2025 survey led by Dr. Bryan Watts of William & Mary’s Center for Conservation Biology found a 90% decline in nesting ospreys within a study area on Virginia’s Delmarva Peninsula.

Only nine pairs were recorded. Compared with surveys from the 1970s and 1980s, Watts described the result as a near-total population collapse. He identified limited prey as the most likely cause while cautioning that no osprey diet studies have been conducted at that location and little is known about changes in its fish populations.

In the lower Chesapeake Bay, the center’s scientists have found that Atlantic menhaden make up nearly 75% of the osprey diet. Some conservationists contend that large-scale commercial harvesting is reducing the supply of the small schooling fish and want government officials to lower catch limits.

Virginia lawmakers have made several unsuccessful attempts in recent years to require a comprehensive study of the menhaden population. The fish support Virginia’s largest commercial fishery and are commonly processed into fishmeal and fish oil. They are also an important food source for striped bass, bluefish and ospreys. Virginia remains the only state permitting reduction fishing for menhaden.

Old Threats and New Hazards

Ospreys generally mate for life and return to the same nest each spring. They usually lay between one and four eggs, which are incubated for 36 to 42 days.

Because the birds keep adding material, nests can grow 10 to 13 feet deep, span three to six feet and weigh as much as 250 pounds. Along with sticks, ospreys sometimes collect shoes, cans, fabric, toys and fast-food waste.

That debris can become deadly. Plastic bags, balloon ribbons, twine and monofilament fishing line may trap adults or chicks in the nest.

During a lifespan of 15 to 20 years, an osprey can migrate more than 160,000 miles.

The birds have rebounded from a major crisis before. Their numbers plunged in the early 1970s after pesticides moving through the food chain caused eggshells to become so thin that they broke during incubation. The Environmental Protection Agency banned DDT in 1972, and osprey populations recovered—but recent declines are renewing concerns about their future.