Facts about Osprey
The Osprey is the only raptor whose outer toe is reversible, allowing it to grasp its prey with two toes in front and two behind. Its toes are of equal length, its tarsi are reticulate, and its talons are rounded, rather than grooved. It reaches a maximum of 60 centimeters (24 in) in length. The Osprey is sometimes known as the sea hawk. It has a 1.8 metre (6 ft) wingspan. While migrating ospreys will cover 260-280 km/day on they average with a maximum of 431 km/day. It is found on all continents except Antarctica, although in South America it occurs only as a non-breeding migrant. As its other common name(sea hawk) suggests, the Osprey's diet consists almost exclusively of fish. Fish make up 99 percent of the Osprey's diet. It typically takes fish weighing 150–300 grams (5–10 oz) and about 25–35 centimetres (10–14 in) in length, but the weight can range from 50 to 2000 grams (2–68 oz). According to a myth, Nisos, a king of Megara in Greek mythology, became a sea eagle or Osprey, to attack his daughter after she fell in love with Minos, king of Crete. The Roman writer Pliny the Elder reported that parent Ospreys made their young fly up to the sun as a test, and dispatch any that failed. Normally, Ospreys reach sexual maturity and begin breeding when they are three to four years of age, though in some regions with high Osprey densities, such as Chesapeake Bay in the U.S., they may not start breeding until five to seven years old, and there may be a shortage of suitable tall structures. If there are no nesting sites available, young Ospreys may be forced to delay breeding. To ease this problem, posts may be erected to provide more sites suitable for nest building. Ospreys usually mate for life. The sexes appear fairly similar, but the adult male can be distinguished from the female by its slimmer body and narrower wings. The breast band of the male is also weaker than that of the female, or is non-existent, and the underwing coverts of the male are more uniformly pale. An odd legend regarding this fish-eating bird of prey, derived from the writings of Albertus Magnus and recorded in Holinshed's Chronicles, was that it had one webbed foot and one taloned foot. While migrating, they have a tendency to fly in the dark. The Osprey tolerates a wide variety of habitats, nesting in any location near a body of water providing an adequate food supply. Their head is white with a dark mask across the eyes, reaching to the sides of the neck. Their eggs are about 6.2 x 4.5 centimeters (2.4 x 1.8 in) and weigh about 65 grams (2.4 oz). The upperparts of the bird are a deep, glossy brown, while the breast is white and sometimes streaked with brown, and the underparts are pure white. The bill of an osprey is black, with a blue cere, and the feet are white with black talons. The irises of their eyes are golden to brown, and the transparent nictitating membrane is pale blue. Their nest is a large heap of sticks, driftwood and seaweed built in forks of trees, rocky outcrops, utility poles, artificial platforms or offshore islets. Average lifespan of these birds is 20–25 years. Breeding season of the Ospreys varies according to latitude; spring (September-October) in southern Australia, April to July in northern Australia and winter (June-August) in southern Queensland. Their eggs are whitish with bold splotches of reddish-brown. The Ospreys incubate their eggs for about 5 weeks. The newly hatched chicks of Osprey weigh only 50–60 grams (2 oz), but fledge in 8-10 weeks. A study on Kangaroo Island, South Australia, had an average time between hatching and fledging of 69 days. There was a medieval belief that fish were so mesmerised by the Osprey that they turned belly-up in surrender, and this is referenced by Shakespeare in Act 4 Scene 5 of Coriolanus:
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