Osprey

Pandion haliaetus

(c) Shawn Carey
  • PANDIONIDAE
  • Falconiformes
  • Gavilán pescador
  • Balbuzard pêcheur
Introduction

One of North America's largest birds of prey, the Osprey is a magnificent fish-eating hawk with a white-crested head, yellow eyes, a white underside, and a dark brown back. The species, once gravely imperiled, has undergone a tremendous resurgence and occurs virtually worldwide, near coastlines, lakes, and rivers, where the birds hunt for their food.

(c) Shawn Carey
Appearance Description

The Osprey weighs three to four pounds, has a wingspan of up to six feet, and is approximately two feet long. Plumage is largely dark brown on top and white underneath. The bird has a black, sharply curved bill, and a white crown and head, with a dark band extending back from behind its yellow eyes. The female is larger than the male, and frequently has a speckled brown necklace across the upper chest. The bird's four pale toes are tipped with long black talons. Barbed pads on their feet and a reversible outer toe help the birds grip slippery fish. In flight, the underwings show dark patches at the wrist (crook), and dark bars at the trailing edge and wing tips.

Range Map
Courtesy Kenn Kaufman
Range Distribution
Found on every continent except Antarctica, the Osprey, or fish hawk, is among the most widely distributed raptors in the world. In North America, it breeds from Alaska through Canada, southward along both coasts to Mexico and the West Indies, and in scattered inland locations, such as around the Great Lakes. The birds mainly winter south of the United States, in Central and South America to central Chile and the northern coast of Argentina, but a few may winter as far north as southern Canada.
 
A legend for the range map to the right can be found here.
Habitat

Ospreys live along seacoasts, inland bays, freshwater reservoirs, and large rivers and lakes, wherever large concentrations of fish are available. They breed in a variety of shallow water habitats, including boreal forest ponds, desert salt-flat lagoons, mangrove and salt marsh islands, and temperate and tropical lakes and seacoasts. They winter in both coastal and interior areas with shallow, clear water nearby.

Feeding

Ospreys subsist almost entirely on live fish. Prey consists of species that typically school at the water's surface or swim in the shallows. Birds hunt on the wing, often hovering over the water when they spot a fish, and then plunging into the water feet first to grab it with their powerful talons. When an Osprey emerges from the water with its catch, it uses its feet to turn the fish headfirst to reduce aerodynamic drag. The bird then flies off with the fish to an elevated perch, often near the nest, and eats it.

Reproduction

Ospreys can reach sexual maturity in three years. At this time, males generally select nesting sites, which are typically close to water, open to the sky, and safe from predators. Locations include treetops, cliffs, large shoreline boulders, and even the ground on small, inaccessible islands. The birds also readily use manmade structures, such as utility poles, channel markers, duck-hunting blinds, and platforms designed especially for Ospreys. Nests are large, built of sticks, and lined with bark, grass, algae, and sometimes, plastic bags. The clutch usually consists of three eggs, which are incubated mostly by the female. Males occasionally pitch in, but they mainly provide their mates with food during the 38-day incubation period. Females then care for the brood, and males continue to provide food. Offspring fledge when they are about 50 to 55 days old, but depend on their parents for nourishment for another 8 weeks.

Migration

Most Ospreys breeding in North America are migratory, except for permanent resident populations in southern Florida, the Caribbean, the Gulf Coast, and Baja, Mexico. American and Canadian breeders, which winter in Central and South America, begin their southbound journeys in August. They return north between late February and April. Migrants travel alone. An Osprey nesting in central Quebec and wintering in southern Brazil may cover more than 120,000 miles during its lifetime.

  • 460,000
  • 211,500
  • increasing population; no current conservation concerns
Population Status Trends
Osprey numbers are on the rise after global numbers plummeted from the 1950s through the 1970s. In the United States, declines were most severe along the North Atlantic coast and in the Great Lakes region. But by the year 2000, most North American populations had rebounded to near-historical abundance levels, with birds reoccupying former habitats and moving into new areas. Some states, however, have not experienced such successful turnarounds, and still list the species as threatened or endangered.
Conservation Issues

Poisoning by DDT and other related pesticides caused eggshell thinning and widespread breeding failures, leading to a sharp drop in Osprey populations. After DDT use was banned in the United States in 1972, the species rapidly rallied. Risks continue to be posed in countries where Ospreys breed and pesticides are not regulated. The birds are also vulnerable to the destruction of nest sites by logging; the conversion of habitat into farmland; declines in water quality and fish populations; shooting; collisions with motor vehicles and stationary structures; and electrocution by power transmission lines and transformers. In many areas, Ospreys have benefited from active management, including the erection of artificial nesting platforms, and the reintroduction of birds into areas where the species has been decimated.

What You Can Do
For actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit our resources page for more information about this species.
Natural History References
Poole, A. F., R. O. Bierregaard, and M. S. Martell. 2002. Osprey (Pandion haliaetus). In The Birds of North America, No. 683 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Kaufman, Kenn. Lives of North American Birds, Houghton Mifflin Company, New York, 1996.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York, 2000.
Conservation Status References
Poole, A. F., R. O. Bierregaard, and M. S. Martell. 2002. Osprey (Pandion haliaetus). In The Birds of North America, No. 683 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Kaufman, Kenn. Lives of North American Birds, Houghton Mifflin Company, New York, 1996.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York, 2000.