Osprey Pandion haliaetus Scientific name definitions

Among the World's best-studied birds of prey, the widely admired Osprey is the only raptor that plunge-dives to catch live fish as its main prey source. Despite its reliance on fish, the Osprey occupies a broad array of habitats, ranging from mangrove islets to boreal forest lakes, and from salt marshes to saline lagoons. Northern populations migrate south to overwinter primarily on fish-rich rivers, lakes, and coastal areas in subtropical and tropical regions, returning north each spring as waters warm and fish become accessible. An Osprey nesting in a northern region and overwintering south of the equator might fly more than 200,000 kilometers during its 15 to 20-year lifetime.

The Osprey dives feet first to capture prey, accessing only about the top meter of water, so it is restricted to foraging for surface-schooling fish and to those in shallow water—the latter generally are most abundant and available. As a result, in many areas it tends to breed most densely where shallow waters abound. In many of these places, artificial nest sites, or nest platforms, have helped breeders enormously in recent decades. Historically, the Osprey built its bulky stick nest atop trees, rocky cliffs, promontories, and even on the ground on a few islands that lack mammalian predators. While some continue to use natural sites, many have shifted to nesting on artificial structures. The species now uses an astonishing array of artificial sites: channel markers in harbors and busy waterways; towers for radio, cell phone, and utility lines; and platforms erected exclusively for the species. This shift has been dramatic in many regions, with 90–95% of pairs choosing to nest at artificial sites; predation, loss of trees, and development of shorelines have been driving forces behind the change.

In North America, the Osprey gained increased recognition from the 1950s to 1970s because populations crashed in several key regions. About 90% of the pairs nesting along the Atlantic coast between New York City and Boston, for example, disappeared during this period; Chesapeake Bay lost more than half of its breeding pairs, and Great Lakes populations also suffered major declines. Studies showed that high levels of contaminants (especially DDT and its derivatives) in eggs, severe eggshell thinning, and poor hatching success were responsible. Mortality of adults may have contributed to the decline. Osprey studies provided key evidence in court to block continued use of persistent pesticides, and Osprey populations recovered rapidly thereafter. Although small pockets of contamination remain, the historic range has greatly expanded and many populations in Canada and the United States now exceed historical numbers, owing to a cleaner environment, increasingly available artificial nest sites, and this bird’s ability to tolerate human activity near its nests. Phoenix-like, the Osprey has arisen from the ashes of its own demise, a survivor, even a backyard bird in some areas today. Indeed, there is little wonder the species has become such a powerful totem for conservation.

Concern for populations impacted by pesticides spawned a multitude of studies on Osprey life history during the 1970s and 1980s, and these have continued almost undiminished since then—the product of Osprey allure, broad distribution, and ease of study (highly visible nesting and hunting, and accessible nests). The life history of the Osprey in North America was summarized by Bent (Bent 1937b Bent, A. C. (1937). Life histories of North American birds of prey, Part 1. U.S. National Museum Bulletin no. 167. Close ), Palmer (Palmer 1988e Palmer, R. S., Editor (1988). Handbook of North American Birds, Volume 4, Part 1: Diurnal Raptors. Yale University Press, New Haven, CT, USA. Close ), and Poole (Poole 1989a Poole, A. (1989a). Ospreys: a natural and unnatural history. Cambridge, U.K: Cambridge Univ. Press. Close ), whereas Cramp and Simmons (Cramp and Simmons 1980b Cramp, S. and K. E. L. Simmons. (1980b). "Osprey." In The birds of the Western Palearctic. Vol. 2: hawks to bustards, 265-277. Oxford, UK: Oxford Univ. Press. Close ) and Dennis (Dennis 2008 Dennis, R. (2008). A life of Ospreys. Dunbeath: Whittles Publishing. Close ) did the same for Osprey breeding in the Palearctic. Although this account, by necessity, leans on these earlier works, we have emphasized more recent studies. Areas of important new research include: analyses of migratory movements based on satellite tracking (Martell et al. 2001a Martell, M. S., C. J. Henny, P. E. Nye and M. J. Solensky. (2001a). Fall migration routes, timing, and wintering sites of North American Ospreys as determined by satellite telemetry. Condor 103:715-724. Close , Martell et al. 2014 Martell, M. S., R. O. Bierregaard, B. E. Washburn, J. E. Elliott, C.J. Henny, R. S. Kennedy and I. MacLeod. (2014). The spring migration of adult North American Ospreys. Journal of Raptor Research 48 (4):309-324. Close , Washburn et al. 2014 Washburn, B. E., M. S. Martell, R. O. Bierregaard, C. J. Henny, B. S. Dorr and T. J. Olexa. (2014). Wintering ecology of adult North American Ospreys. Journal of Raptor Research 48 (4):325-333. Close ); navigational abilities (Horton et al. 2014 Horton, T. W., R. O. Bierregaard, P. Zawar-Reza, R. N. Holdaway, and P. Sagar (2014). Juvenile Osprey navigation during trans-oceanic migration. PLOS One 9(12):1–32. Close ); behavior at the nest (Birkhead and Lessels 1988 Birkhead, T. R. and C. M. Lessels. (1988). Copulation behaviour of the Osprey. Animal Behaviour 36:1672-1682. Close , Bretagnolle and Thibault 1993 Bretagnolle, V. and J. C. Thibault. (1993). Communicative behavior in breeding Ospreys (Pandion haliaetus): description and relationship of signals to life history. Auk 110:736-751. Close ); molecular genetic studies to determine Osprey systematics (Seibold and Helbig 1995b Seibold, I. and A. J. Helbig. (1995b). Systematic position of the Osprey (Pandion haliaetus) according to mitochondrial DNA sequences. Vogelwelt 116:209-217. Close ) and phylogeography (Monti et al. 2015 Monti, F., O. Duriez, V. Arnal, J.-M. Dominici, A. Sforzi, L. Fusani, D. Gremillet and C. Montgelard. (2015). Being comopolitan: Evolutionary history and phylogeography of a specialized raptor, the Osprey Pandion haliaetus. BMC Evolutionary Biology 15. Close ); foraging and development of dietary preferences in the postfledging period (Edwards and Collopy 1988 Edwards, T. C. and M. W. Collopy. (1988). Nest tree preference of Ospreys in northcentral Florida. Journal of Wildlife Management 52:103-107. Close , Edwards 1989b Edwards, Jr., T. C. (1989b). Similarity in the development of foraging mechanics among sibling Ospreys. Condor 91:30-36. Close ); assessment of contaminants in western populations (Henny et al. 1991b Henny, C. J., L. J. Blus, D. J. Hoffman, R. A. Grove and J. S. Hatfield. (1991b). Lead accumulation and Osprey production near a mining site on the Coeur d'Alene River, Idaho. Archives of Environmental Contamination and Toxicology 21:415-424. Close , Elliott et al. 1994 Elliott, J. E., P. A. Martin, T. W. Arnold and P. H. Sinclair. (1994). Organochlorines and, reproductive success of birds in orchard and non-orchard areas of central British Columbia, Canada, 1990-1991. Archives of Environmental Contamination and Toxicology 26:435-443. Close , Elliott et al. 2000 Elliott, J. E., M. M. Machmer, L. K. Wilson and C. J. Henny. (2000). Contaminants in Ospreys from the Pacific Northwest; II. Organochlorine pesticides, polychlorinated biphenyls, and mercury, 1991-1997. Archives of Environmental Contamination and Toxicology 38:93-106. Close , Elliott et al. 2001b Elliott, J. E., L. K. Wilson, C. J. Henny, S. F. Trudeau and F. A. Leighton. (2001b). Assessment of biological effects of chlorinated hydrocarbons in Osprey chicks. Environmental Toxicology and Chemistry 20:866-879. Close ); status of North American populations in the Great Lakes (Ewins 1995 Ewins, P. J. (1995). "Recovery of Osprey populations in Canada." In Bird trends, edited by C. Hyslop, 14-16. Toronto, ON: Can. Wildl. Serv. Close , Ewins 1996 Ewins, P. J. (1996). "The use of artificial nest sites by an increasing population of Osprey in the Canadian Great Lakes basin." In Raptors in human landscapes., edited by D. M. Bird, D. E. Varland and J. J. Negro, 109-123. San Diego, CA: Academic Press Inc. Close , Ewins 1997 Ewins, P. J. (1997). Osprey (Pandion haliaetus) populations in forested areas of North America: changes, their causes and management recommendations. Journal of Raptor Research 31:138-150. Close , Ewins et al. 1995a Ewins, P. J., S. Postupalsky, T. Weise and E. M. Addison. (1995a). "Changes in the status, distribution, and biology of Ospreys (Pandion haliaetus) breeding along Lake Huron." In The Lake Huron ecosystem: ecology, fisheries, and management., edited by M. Munawar, T. Edsall and J. Leach, 273-290. Amsterdam: SPB Acad. Publ. Close , Ewins et al. 1999 Ewins, P. J., S. Postupalsky, K. D. Hughes and D. V. Weseloh. (1999). Organochlorine contaminant residues and shell thickness of eggs from known-age female Ospreys (Pandion haliaetus) in Michigan during the 1980s. Environmental Pollution 104:295-304. Close ); sibling aggression among nestlings (Forbes 1991 Forbes, L. S. (1991). Hunger and food allocation among nestlings of facultatively siblicidal Ospreys. Behavioral Ecology and Sociobiology 29:189-195. Close ); colonial nesting (Hagan and Walters 1990 Hagan, J. M. and J. R. Walters (1990). Foraging behavior, reproductive success, and colonial nesting in Ospreys. Auk 107:506–521. Close ); lifetime reproduction (Postupalsky 1989b Postupalsky, S. (1989b). "Osprey." In Lifetime reproduction in birds., edited by I. Newton, 297-313. London, U.K: Academic Press. Close ); and growth of nestlings (Steidl and Griffin 1991 Steidl, R. J. and C. R. Griffin. (1991). Growth and brood reduction of mid-Atlantic coast Ospreys. Auk 108:363-370. Close , Schaadt and Bird 1993 Schaadt, C. P., and D. M. Bird (1993). Sex-specific growth in Ospreys: the role of sexual size dimorphism. Auk 110:900–910. Close ).