|P.O. Box 240
2756 Dam Road
Errol, NH 03579
Osprey (Pandion haliaetus)
Often called "Fish Hawk"
Ospreys are 22.5 - 25 inches long and have a wingspan of 4.5 - 6 feet. Their bodies are dark brown on the top and white on the bottom. The head is white, with a dark cheek patch. The females have a necklace of dark feathers around their necks (Peterson, 1980). Ospreys are often confused with eagles. The distinguishing characteristic of the osprey is its dark cheek patch.
The can be found on every continent in the world except Antarctica (Unitt, 2000). In New Hampshire, ospreys are more abundant in Coos County than in southern parts of the state.
Ospreys live almost exclusively on fish . They'll sometimes eat dead fish or small mammals when there aren't enough live fish to feed on or they are in migration (Unitt, 2000). Once an osprey spots its prey, it hovers over it and then plunges into the water, grasping the fish with its talons.
Ospreys live near water and usually nest in the tops of tall dead trees.
Ospreys are unlikely to nest in an area where food is scarce (Evans. 1994) Ospreys generally nest in the open because they have difficulty maneuvering in confined areas. It is common for them to nest on cliffs or the tops of telephone poles, or on platforms built specifically for osprey nesting. Nests resemble eagle nests and are made of twigs. Some ospreys reuse these nests for several years. Each year the birds bring new materials to add on to the nests, so the nests may weigh hundreds of pounds (Unitt, 2000). Ospreys return to nesting sites in northern New Hampshire throughout April and May.
The osprey lays three to four white eggs with dark blotches. Ospreys in the Umbagog area lay eggs between late April and late May. They are incubated for about 38 days and usually only one or two of the young survives (Unitt, 2000). Young will stay in the nest for approximately eight weeks until they are ready to fledge.
Human disturbance has had a great impact on osprey populations. In the past ospreys were hunted and sometimes killed by fishermen who believed they were competing for fish. Habitat loss due to human activity has been a major cause of local extinction in some areas. The use of DDT has also radically affected osprey populations (Evans, 1994). DDT was commonly sprayed as an insecticide after World War Two (Kalakotkas, 1998). Because of the bioaccumulation of the insecticide, high amounts were found in ospreys.
DDT causes osprey eggs to become so thin that they may be crushed during incubation (Kalakotkas, 1998). Due to the harmful effects it had on the environment, the use of DDT was banned for most uses in the United States in 1972, and efforts were made to help the species that suffered from its use.
Ospreys of Lake Umbagog
Ospreys were common in the Umbagog Lake area in the late 1800s (Evans, 1994). Due to DDT, the numbers in the area dropped drastically. Following population decline, intensive monitoring and management activities were put in place by the New Hampshire Audubon Society. Aerial surveys were conducted to locate osprey nests for monitoring. Metal protector guards were also installed on the bases of nest trees to reduce predation of eggs by raccoons. The public and large landowners were informed about the importance of osprey nesting sites. Artificial nesting platforms have also been built.
In 2006, about 26% of all osprey territories in New Hampshire were in the vicinity of Umbagog Lake and about 52% of all nests in the state were in Coos County, in northern New Hampshire (Martin, 2006). 2005 and 2006 were the most productive osprey breeding seasons in the state in 27 years. However numbers of active osprey nests in the Umbagog area seem to have decreased somewhat in recent years.
For more information on ospreys in New Hampshire, visit the NH Audubon web site.
Where to look for osprey
The best place to see these birds is perched on the tops of old dead white pine trees. A few nests are visible along the Magalloway River, and along the Androscoggin River. The large stick nests are found in the tops of large trees, particularly white pine trees. It is important that people use caution around osprey nests. Although they are not protected by float lines it is still important to respect the osprey nesting territory. If the osprey feels threatened it will leave the nest, leaving the eggs or young open to predation.
Status of the osprey
The osprey is classified as a threatened species in New Hampshire. Its breeding range in the state is limited to large lakes and rivers and the wetlands surrounding them (Martin, 1995). Ospreys breed in every part of New Hampshire except the southwestern region (Martin, 2000).
Ospreys are more common in Maine and are currently not listed on the threatened or endangered lists. Maine has a large coastline that provides abundant habitat for ospreys.
Osprey, written by Katie Maguire, 7/01
For more information, please contact:
Umbagog National Wildlife Refuge.
Evans, Diane. 1994 Atlas of Breeding Birds in New Hampshire. Chalford Publishing Corporation. Dover, NH.
Martin, Chris. 2006. Status of breeding ospreys in New Hampshire in 2006. Audubon Society of New Hampshire.
Martin, Christian J. 1995. Osprey Breeding Status in Coos County, New Hampshire In 1995. Audubon Society of New Hampshire.
Peterson, Roger T. (1980). Peterson Field Guides: Eastern Birds. Houghton Mifflin Company
Unitt, Philip, 2000. Ocean Oasis Field Guide. Pandion Haliaetus. 2000 San Diego Natural History Museum