Ospreys live near water, such as rivers, lakes and the coast. Ospreys eat almost nothing but fish. The osprey typically feeds on fish 4 to 12 inches long. As of November 2026, studies in North America have documented more than 80 different prey species of ospreys; ospreys do not generally need to drink water, because fish flesh supplies enough water to meet their needs. An osprey flies over the water and hovers, and then it plunges toward the water to catch a fish. Ospreys hunt for fish from the air, flying up to about 40 meters above the water.
National Geographic says ospreys hunt by diving to the water's surface from some 30 to 100 feet up; ospreys have been known to dive up to one metre below the surface of the water to catch prey. An osprey uses strong, almost horizontal wing beats to lift itself and its prey from the water; an osprey watches for movement just beneath the surface of the water. Ospreys catch fish on about a quarter or more of their dives. How often an osprey catches a fish depends on its own ability, the weather and the tide; some studies have shown that ospreys are most successful at hunting at midtide and when the weather is calm. Breeding ospreys are known to travel as far as 14 km from their nest during hunting forays.
Because of its bones, muscles and feather tracts, the osprey is placed in its own family, Pandionidae, apart from hawks and eagles. Ospreys have four types of colour receptors in the eye, while people have three; an osprey's eyes also have a very high density of receptors, which gives it much better visual acuity than people have. An osprey has rough pads on its feet that help it hold a slippery fish. The underside of its feet has rough, spiny pads called spicules, and an outer toe on each foot can swing around to join the rear toe; ospreys have relatively long legs for a raptor. An osprey has a see-through third eyelid that it closes when it dives into the water. Ospreys have dense oily plumage and efficient nasal valves that prevent water from entering the nostrils; the pale underside of an osprey's plumage can help it blend into the bright sky.
Widespread use of the pesticide DDT caused osprey numbers to fall in the mid-1900s. During the height of the DDT era, breeding ospreys along the Elizabeth River in Virginia disappeared completely; osprey numbers in North America largely rebounded after DDT was banned. After a 1972 cancellation order for DDT, the concentration of DDT in osprey eggs declined. The osprey population in the Chesapeake Bay fell to a low of about 1,450 pairs in the early 1970s; by the mid-1990s there were about 3,500 pairs of breeding ospreys in the Chesapeake Bay area. As of November 2026, the Chesapeake Bay Program places the Chesapeake Bay's current osprey population at eight to 10,000 breeding pairs. As of November 2026, the Chesapeake Bay supports one of the largest osprey breeding populations in the world.
Ospreys build large stick nests on telephone poles, channel markers and other structures. Ospreys choose nest structures that can support a bulky nest and that are safe from ground-based predators. Access to trees or man-made platforms to nest in is crucial for the survival of ospreys; osprey pairs use the same nest year after year. Ospreys add new material to their nest each year, so the nest can become huge; an osprey lays two to four eggs over several days, each one 1 to 2 days after the one before. Osprey incubation starts when the first egg is laid, so the eggs hatch in the order in which they were laid. Osprey eggs hatch after about 40 days of incubation. Young ospreys take their first flight at about 50 to 55 days old. Ospreys are sexually mature at about 3 years old, but may not breed until age 5 where nest sites are scarce.
Most ospreys breed in the north and migrate south for the winter; ospreys migrate alone, not in flocks. Ospreys heading south from the Midwest and East Coast populations average about 130 miles a day; the yearly migration of UK ospreys is a round trip of some 12,000 km. Some young ospreys tagged on Martha's Vineyard cross over 1,000 miles of the Atlantic before they get to the Bahamas. Nonstop ocean flights by tagged ospreys can last more than 50 hours.
