The osprey tolerates a wide variety of habitats, nesting in any location near a body of water providing an adequate food supply.

The osprey was described in 1758 by the Swedish naturalist Carl Linnaeus under the name Falco haliaetus in his landmark tenth edition of his Systema Naturae.

[4][5] The osprey is the only species placed in the genus Pandion that was introduced by the French zoologist Marie Jules César Savigny in 1809.

[4] The Sibley-Ahlquist taxonomy has placed it together with the other diurnal raptors in a greatly enlarged Ciconiiformes, but this results in an unnatural paraphyletic classification.

[16] Pandion homalopteron described by Stuart L. Warter in 1976 was found in marine Middle Miocene deposits of the Barstovian age in the southern part of California.

The second species Pandion lovensis was described by Jonathan J. Becker in 1985 and found in Florida; it dates to the Late Clarendonian and possibly represents a separate lineage from that of P. homalopteron and P. haliaetus.

[citation needed] The oldest recognized family Pandionidae fossils were recovered from the Oligocene age Jebel Qatrani Formation in Faiyum Governorate, Egypt.

[17] Another Pandionidae claw fossil was recovered from Early Oligocene deposits in the Mainz basin, Germany, and was described in 2006 by Gerald Mayr.

The species name haliaetus (Latin: haliaeetus)[19] comes from Greek ἁλιάετος haliáetos "sea-eagle" (also ἁλιαίετος haliaietos) from the combining form ἁλι- hali- of ἅλς hals "sea" and ἀετός aetos, "eagle".

[31] The sexes appear fairly similar, but the adult male can be distinguished from the female by its slimmer body and narrower wings.

During spring, barring on the underwings and flight feathers is a better indicator of a young bird, due to wear on the upperparts.

[45] Occasionally, the osprey may prey on rodents, rabbits, hares, other mammals, snakes, turtles, frogs, birds, salamanders, conchs, and crustaceans.

Rocky outcrops just offshore are used in Rottnest Island off the coast of Western Australia, where there are 14 or so similar nesting sites of which five to seven are used in any one year.

The nest is a large heap of sticks, driftwood, turf, or seaweed built in forks of trees, rocky outcrops, utility poles, artificial platforms, or offshore islets.

[41][51] As wide as 2 meters and weighing about 135 kg (298 lb), large nests on utility poles may be fire hazards and have caused power outages.

The nesting platform plans and materials list, available online, have been utilized by people from a number of different geographical regions.

[58] American and Canadian breeders winter in South America, although some stay in the southernmost U.S. states such as Florida and California.

[61] European birds may also winter in South Asia, as indicated by an osprey tagged in Norway being monitored in western India.

[62] In the Mediterranean, ospreys show partial migratory behaviour with some individuals remaining resident, whilst others undertake relatively short migration trips.

[64] These deaths can also be categorized into spatial patterns: Spring mortality occurs mainly in Africa, which can be traced to crossing the Sahara desert.

[1] There is evidence for regional decline in South Australia where former territories at locations in the Spencer Gulf and along the lower Murray River have been vacant for decades.

[68] The pesticide interfered with the bird's calcium metabolism which resulted in thin-shelled, easily broken or infertile eggs.

[34] Possibly because of the banning of DDT in many countries in the early 1970s, together with reduced persecution, the osprey, as well as other affected bird of prey species, have made significant recoveries.

[41] In South Australia, nesting sites on the Eyre Peninsula and Kangaroo Island are vulnerable to unmanaged coastal recreation and encroaching urban development.

[78] During the 2017 regular session of the Oregon Legislature, there was a short-lived controversy over the western meadowlark's status as the state bird versus the osprey.

The sometimes-spirited debate included state representative Rich Vial playing the meadowlark's song on his smartphone over the House microphone.