The adult is blackish-brown above and white below; the breast is white or sometimes shows a brown band (especially in females). The head is mostly white with a broad black stripe extending from the eye to the back. Bill and talons are black and eyes are yellow to orange. Ospreys range in size from 21" - 25" long with a wingspan of 59"- 67". Females are about 10 percent larger than males weighing from 2.5 - 4.25 pounds while males weigh 2.25 - 3.75 pounds.
Immatures are similar to adults except the upper feathers have light edges, while the underparts are buffy.
Ospreys are primarily found along streams, rivers, lakes and reservoirs where they forage for fish.
The osprey’s main prey is fish. This bird is the only raptor to plunge into the water for prey. Usually, the osprey will hover 30 - 100 feet above the water watching for fish. When a fish is spotted, the osprey dives feet first into the water and is often momentarily under the surface of the water. Once capturing the fish, the osprey leaves the water, shakes the water from its feathers and positions the fish in its talons so that the fish’s head faces forward. This decreases wind resistance as the osprey flies. Ospreys are reported to be able to carry up to 2.25 pounds, but most fish are in the 0.5 lb. range and are 5-15" in length. Osprey occasionally eat rodents, birds, small vertebrates and crustaceans. To feed their young, adult ospreys tear off small pieces of fish when the chicks are very young and adjust size as they get older. A brood of three chicks requires nearly two pounds of fish daily.
The osprey’s method of catching prey calls for some adaptations not found in more terrestrial hawks. The osprey’s feathers are slightly oily to limit water absorption. The shank of the leg is scaled, not feathered, with short, dense feathering on the thighs. The pads of the toes are covered with spicules (small spikes) for grasping slippery fish. The osprey also has a reversible outer toe that can either be at the front of the foot or moved to the back for a two toe forward, two toe back formation for carrying fish.
Osprey build nests near the water; 10 - 60 feet above the ground near the tops of trees. They can also nest on the ground or on cliffs and use a variety of structures, including power poles, chimneys, channel markers, and duck blinds. The nest is built of sticks and lined with grasses, seaweed, moss, lichens, bark, and even mud. These raptors return to the same nest each year and add to it. Adults defend the nest, often attacking intruders. Osprey nest singly or in loose colonies.
Average clutch size is 3, range is 2-4. Eggs are 2.5" x 1.75" in size and are white or buffy in color with heavy brown or reddish-brown spotting. In America, the female is the primary incubator. Incubation lasts 37-38 days. The young birds fledge at 48-59 days of age. They reach sexual maturity at three years. Midwestern osprey winter in South America and young osprey spend their first two winters and first summer in wintering areas before returning north.
The osprey is one of the most widely distributed birds in the world, found on every continent except Antarctica. The population declined rapidly in the 1950s - 1970s due to DDT, loss of breeding grounds and poaching. The ban of DDT in combination with statewide conservation programs, including the use of artificial nesting platforms, helped the population regain its footing.
In Indiana, the osprey is on the state endangered species list. In general, ospreys were considered a spring and fall migrant in Indiana with few breeding pairs found in the state. Nesting records for the 20th century included single nesting reports in three counties (Morgan, 1962; Parke, 1931 and 1971; and Porter, 1934) and nesting from 1932-1969 in Posey County. A restoration effort was undertaken from 2003-2006 when 96 young ospreys were acquired from nests in coastal areas of Virginia. They were released at four locations in Indiana. As a result of this effort and the erection of nesting platforms through a partnership between the Indiana Department of Natural Resources and private groups and individuals, Indiana’s osprey population has shown steady growth. In 2014, 68 sites had osprey or osprey nests present, of which 59 are believed to have laid eggs.