Fish hawks breed on all continents except Antarctica
Ospreys (Pandion haliaetus)—once sea hawks or fish hawks—are daytime fish hunters with a near-global range. They miss Antarctica as breeders and visit South America only as nonbreeding migrants, nesting on poles, cliffs, and platforms wherever open water offers prey.
Linnaeus first gave Europe as the type locality, then narrowed it to Sweden in 1761. Savigny created the genus Pandion in 1809, naming it after a mythical king of Athens, while haliaetus means sea eagle in Greek. The word osprey, first written around 1460, came through Anglo-French from Latin for bird of prey, though the Oxford English Dictionary also notes Pliny's ossifraga, the bone breaker, a name that actually meant the bearded vulture. Molecular work shows its family, Pandionidae, is the sister of the hawk and eagle family, the two parting roughly 50.8 million years ago.
Four subspecies are usually listed, though the differences are slight. The American bird is larger and darker-bodied; the Australasian form is the smallest, stays put year-round, and is sometimes treated as a separate eastern osprey, although a 2018 genetic study found little divergence; Ridgway's osprey of the Caribbean has a very pale head and faint mask. Fossil relatives include a Middle Miocene species from California, one from Florida, and Oligocene material from Egypt's Faiyum, Hungary and Germany.
Adults weigh 0.9 to 2.1 kg with wingspans up to 180 cm, comparable to the biggest buzzards and falcons. Only the osprey and owls among raptors can swing the outer toe backward, gripping slippery fish with two toes in front and two behind, and its talons are rounded rather than grooved.
The back is glossy dark brown, the underparts white, and a dark mask runs from the eyes down the neck. Black wrist patches under the wings and long narrow wings with four finger-like outer feathers make it easy to pick out in flight. Males are slimmer, with narrower wings and a weaker breast band, and juveniles show buff edges on their upper feathers.
Source: Osprey
