Osprey

Pandion haliaetus

Taxonomy:
Class: Aves
Order: Falconiformes
Family: Accipitridae
Subfamily: Pandioninae
Genus: Pandion

Length: 21-26 in.
Weight: 2.2-4 lbs.
Wingspan: 59-67 in.

Common Names: fish hawk

Etymology: pandion - Greek name of a mythical king of Athens who was transformed into a bird; haliaetus (Greek) - "sea eagle"

Description: The osprey is generally dark on the back and wings with white on the top of the head and extending from under the chin down the belly. A black stripe runs through the eye to the nape. Osprey lack the supra orbital (or superciliary) ridge (bony plate over the eyes) that hawks and eagles have. In flight, the osprey can be distinguished from the bald eagle by the white belly and the crooked wings with dark wrist patches. Immature osprey have a "scaly" appearance because of white feather edges on the back and upper wing coverts. Females have more of a necklace than males. Iris color changes from red to yellow with increasing age. Osprey have unique nostrils that are usually long, slit-like and closeable.

Flight: Active flight is on slow, steady, shallow wingbeats on somewhat flexible wings. Soars and glides with wings crooked in a gull-winged shape. Hovers frequently when hunting over water.

Voice: Alarm call is a series of loud "kip" notes gradually rising in pitch, up to 20 calls in six seconds.

Habitat: Wherever fish and nest sites are available. Do not defend a definable territory, just their nest location. In areas that support it, Osprey will nest in almost colony-like groups.

Distribution: The osprey is found around the world (cosmopolitan) where there are appropriate nesting sites and adequate supplies of fresh fish that can be caught near the water surface. Osprey are found along coastlines, rivers, lakes, and even man-made reservoirs anywhere in North America. Occasionally found around salt marshes.

Nesting: Osprey will reuse old nest sites, renovating and adding new materials. They seem to prefer emergent trees with tops broken or dead (open nest sites for visibility), and they also like sites that are over water. Island populations are known to build nests on the ground. One to 5 eggs are laid (average 3) at intervals of one to three days. Incubation lasts 34-40 days, and is done by both sexes. Average fledgling 48-59 days, although the young remain dependent on the parents for another 4-8 weeks, terminating prior to start of fall migration. May breed at 3 years. Orton Pond, North Carolina once had highest nesting density of osprey in North America, 61 pairs in 1974. Nesting materials have included brush wood, sea wood, corn stalks, shingles, small float, toy boat, eggs of sharks, old broom, old shoes, fishing line, cans, doormat, sheep bones (especially skulls), sod with the grass still growing.

Food: Osprey eat almost exclusively fish, and they capture prey in a specialized manner, which tends to reduce competition from other raptors. Tend to take species that are prone to basking or feeding near water surface (need water clarity). Dense feathers on their chest provide protection when hitting the water. Osprey feet are specially designed to capture fish. Sharp spines called spicules, which aid the birds in gripping their prey, cover the bottoms of their feet. They also have a flexible outer toe that allows them to grip their prey with two toes in front and two toes in back (zygodactyl). Talons are also more curved than most raptors and they even have a long talon on the "little" or outer toe, unlike other raptors. Osprey carry fish "torpedo" style - headfirst.