Birds Posters
Ospreys
The Osprey, Pandion haliaetus whose species name is derived from the Greek hals (salt or sea) and aetos, or eagle is the only bird of prey that feeds exclusively on live fish.
Their eggs do not hatch all at once, but instead the first chick hatches out up to five days before the last one.
Their outer toe is reversible so that it can grasp with three toes forward and one toe backward or with two forward and two backward, which provides a more stable grip in flight.
Ospreys have a worldwide distribution, wintering or breeding on every continent except Antarctica.
Ospreys are not known to breed in South America or Indo-Malasia, but are sometimes found there in the winter. Ospreys are winter breeders in Egypt and some Red Sea islands.
Ospreys are large birds of prey (55 to 58 cm long), with a wingspan ranging from 145 to 170 cm.
Their long wings have a characteristic bend at the carpal ("wrist") joints.
They are bright white underneath, with dark brown patches at the carpal joints and a mottled dark brown necklace.
Other identifying markings include a dark stripe through each eye, and a dark brown back. The feet of this species are pale blue-gray, and the beak is black.
Some ospreys migrate seasonally, but not all. Non-migratory populations breed and winter in the same location, though they may wander several hours from their nest during the non-breeding season.
These populations begin breeding between December and March. Migratory populations generally breed where winters are cold enough to drive fish into deep water where they are inaccessible.
Both male and female ospreys care for their young. Ospreys provide parental care by protecting their young from from predators and weather, and by feeding them.
During incubation and the nestling stage, the male osprey provides food to the female and the chicks.
Ospreys are a relatively long-lived bird species. The oldest known osprey in North America was a 25-year old male.
The oldest known female was 23 years old.
However, very few individuals live to this age.
Ospreys are unusual among raptors for being piscivores.
Ospreys hunt for fish on the wing (less often from a perch), flapping and gliding 10 to 40 meters above the water.
When an osprey spots a fish, it hovers briefly, then dives toward the surface of the water.
Just before hitting the water, the osprey swings its legs forward and bends its wings back, plunging feet-first into the water.