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Osprey, Pandion haliaetus
The Osprey, (Pandion haliaetus), is a raptor or bird of prey. Ospreys weigh between three or four pounds, and are between 21 and 32 inches in length (National Wildlife Federation). They have a wingspan between 50 and 72 inches wide. They are mostly brown on their backs and white on their bellies. The male’s belly is completely white while females have a band of brown feathers around their necks and upper chests. The head is generally a white to grey color with a black strip that goes from the eyes to the back of the head. They have big, yellow eyes that makes the band look like a mask (Avian Web). The females tend to be heavier, taller and wider than the males (Cornell Lab of Ornithology. 2009). Their beaks are black and have sharp hooks that are used for ripping apart prey. They also have reversed talons on their feet that are used to pierce prey when caught in order to prevent its escape (The Cornell Lab of Ornithology. 2015).
Ospreys Talons Photo by Lamberti Michele
As the ospreys age, they develop black spots on their feathers. Ospreys do not have any correlation in feather patterns with other birds within the raptor class. Ospreys do though share general identification features such as their color, and marking patterns but vary ever so slightly between each individual osprey (The Journal of Wildlife Management).
Osprey with prey Photo by Finiky
Their diet consists of 99% fish and aquatic animal species giving them the nickname, “The Fish Eagle” (Osprey’s Journey). Though having a fish based diet they will also eat snakes, frogs, birds and other similar wetland animals (The Peregrine Fund). They catch their prey by flying over the water until they spot a fish near the surface. They always live close to water sources such as lakes, rivers, creeks etc. anywhere that will contain a sufficient source of fish (Audubon). A number of their physical features aid them in catching their prey including their oily feathers that keep the water from weighing them down (they then shake them vigorously when they begin to fly to remove any excess water). While flying off with their prey they also re-position the fish to face forward for better aerodynamics (Indiana Department of Natural Resources). Ospreys tend to eat every part of what they catch except for the intestines, which they rip out with their beak and discard once they begin to feed (Courtship Feeding and Osprey Reproduction).
Male Osprey. Photo by Oregon Department of Fish and Wildlife
Ospreys begin to breed around the age of three. When the eggs are laid it will take around 40 days or so for them to hatch (Pennsylvania Game Commission). Prior to the ospreys’ breeding, the female will tend to do less and less while preparing to lay her eggs. The male will often begin providing food for himself and the female when eggs are laid and continue doing so throughout incubation. Surprisingly the female gains only a slight amount of weight before egg laying but is able to produce elevated levels of metabolic heat during incubation (Courtship Feeding and Osprey Reproduction). If the area where the ospreys breed does not have a sufficient food supply, it will directly affect the young. Insufficient food supplies can delay chick development for up to 10 days or more if death does not occur form mal-nourishment (McLean K. Peter). The male may incubate the eggs but only for a short periods of time because of his inability to generate high levels of metabolic heat, and also because of the size difference between the male and the female. Once the chicks hatch it only takes them 35 days to begin to fledge. During that time the chicks rely on the parents for food. The male generally provides most of nestlings food and spends a great deal of time hunting for food and defending the nest from predators (Ajmi Amal R.).
Fully developed nest Photo by Westerveld Esther
Ospreys were very close to becoming extinct because of the widespread use throughout the a950’s and 1960’s of the pesticide, DDT. DDT was used to kill pests on farm crops but its residues then got carried into waterways and affected aquatic life. The DDT would then move up through the aquatic food chains and affect any animal species that rely on aquatic organisms for food. In some areas the populations of ospreys fell to less than 10% of what they were prior to DDT use (Bierregarrd O. Richard). Once the effects of DDT were realized it was soon banned. Once it was discontinued it took about 10 years to see recovery of the osprey populations (Bierregarrd O. Richard). Over the past 40 years the population of ospreys has increased by 1100%, and this increase is continuing (Birdlife International).
Adult Female Osprey Photo by Lamberti Michele
Now that the species has recovered there are problems with population distribution and overcrowding. The recovery of the osprey was aided by human interventions such as the construction of nesting platforms and the passage of laws to prevent poaching (Bierregard O. Richard, A. F. Poole). Now that the population has recovered, though, there are a number of human related problems. Limited nesting locations have caused some ospreys to nest on electrical components like telephone poles, communication towers and other electrical structures which can led to damage and malfunction of these structures (Washburn E. Brian). Human generated air pollution and resource limitations also have large impacts on osprey nesting (Toschik C. Pamela).
Ospreys have specific migratory patterns. Ospreys from Eastern North American will migrate down through Florida, over Cuba and into South America (Mark S. Martell). The ospreys tend to begin migration around September and stay in their wintering location until March. They will spend up to half a year in their wintering locations and tend to travel alone. All ospreys tend to use the same wintering location each year and return back to their summer, breeding locations each year as well with only slight variations in location (Wintering Ecology of Adult North American Ospreys).
General References:
Gross, Doug.”Osprey.” Pennsylvania Game Commission. 2014, September 15, 2016.
“ Osprey,” Indiana Department of Natural Resources. 2016,
“Osprey.” Audubon Guide to North American Birds.,2016, September 15, 2016.
“Ospreys.” Avian Web Beauty of Birds., 2011, September 15, 2016.
“Osprey’s Journey.” Jamaica Bay Wildlife. 2015, September 15, 2016.
“Osprey.” National Wildlife Federation. 2016, September 15, 2016.
“Osprey.” The Cornell Lab of Ornithology. 2015, September 15, 2016.
“Osprey.” The Peregrine Fund. 2016, September 15, 2016.
“Pandion Haliaetus.” The Cornell Lab of Ornithology. 2009, September 15, 2016.
“Species Factsheet: Pandion Haliaetus” Birdlife International. 2016, September 15, 2016.
Scientific References:
Ajmi, Amal R. “Behavioral Observations of Ospreys Breeding at Wainwright, Alaska.” Arctic. Vol. 68, No. 3, September 2015, PP. 293- 300. Wildlife & Ecology Studies Worldwide. DIO: 10.14430/arctic4500.
Bierregard O. Richard, A. F. Poole, B. E. Washburn. “Ospreys (Pandion Halieatus) in the 21st Century: Populations, Migration, Management, and Research Priorites.” The Journal of Raptor Research. Vol. 48, No. 4, 2014, PP. 301-308. Wildlife & Ecology Studies Worldwide, DIO: 10.3356/0892-1016-48.4.301
Bierregarrd O. Richard, A. B. David, L. Gibson, R. S. Kennedy, A. F. Poole, M. S. Scheibel, J. Victoria. “Post-DDT Recovery of Osprey (Pandion Haliaetus) Populations in Southern New England and Long Island, New York, 1970-2013.” Journal of Raptor Research. Vol. 48, No. 4, 2014, PP. 361-374. Wildlife & Studies Worldwide. DIO: 10.3356/JRR-OSPR-14-04.1.
Bretagnolle Vincent, J. Thibault, J. Dominici, “Field Identification of Individual Ospreys Using Head Marking Pattern.” The Journal of Wildlife Management. Vol. 58, No. 1, 1994, PP. 175-178. Wildlife & Ecology Studies Worldwide.
Mark S. Martell, R. O. Bierregaard, B. E. Washburn, J. E. Elliott, C. J. Henny, R. S. Kennedy, I. MacLeod, “The Spring Migration of Adult North American Ospreys.” The Journal of Raptor Research. Vol. 48, No. 4, PP. 309-324. The Journal of Wildlife Management. DIO: 10.3356/JRR-14-00035.1.
McLean K. Peter, M. A. Byrd, “Feeding Ecology of Chesapeake Bay Ospreys and Growth and Behavior of Their Young.” Vol. 103, No. 1, 1991, PP. 105-111. Wildlife & Ecology Studies World Wide.
Poole, Alan. “Courtship Feeding and Osprey Reproduction.” The Auk. Vol. 102, No. 3 July 1985, PP. 479-492. Wildlife & Ecology Studies Worldwide.
Toschik C. Pamela, “Evolution of Osprey Habitat Saitability and Interaction with Contaminant Exposure.” The Journal of Wildlife Management. Vol. 70, No. 4, 2006, PP. 977-988. Wildlife & Ecology Studies Worldwide
Washburn E. Brian. “Human-Osprey Conflicts: Industry, Utilities, Communication and Transportation.” Journal of Raptor Research. Vol. 48, No. 4, 2014, PP. 387-395. Wildlife & Ecology Studies World Wide, DIO: 10.3356/JRR-OSPR-13-04.1
Washburn E. Brian, M. S. Martell, R. O. Bierregaard, C. J. Henny, B. S. Dorr, T. J. Olexa, “Wintering Ecology of Adult North American Ospreys.” Journal of Raptor Research. Vol. 48, No. 4, 2014, PP. 325-333. Wildlife & Ecology Studies Worldwide, DIO: 10.3356/JRR-OSPR-13-01.1
Image Gallery
Westerveld, Esther. “Visarend (Pandion haliaetus) – Haven- Hampton VA.” Flickr, 19 June, 2012, www.flickr.com. Used by creative commons.
- Fully Developed Osprey Nest
Finiky. “Pops with a snack.” Flickr, 27 April, 2009, www.flickr.com. Used by creative commons.
- Osprey with fish
Lamberti, Michele. “Osprey Pandion Haliaetus Falco Pescatore Maremma.” Flickr, 28 September, 2012, www.flickr.com. Used by created commons.
- Female osprey
- Osprey talons
Oregon Department of Fish & Wildlife. “1222_osprey_close_munsel_odfw.” Flickr, 3 April, 2008, www.flickr.com. Used by creative commons.
- Male osprey on wooden post