ML060940315
| ML060940315 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/03/2004 |
| From: | US Dept of Interior, Fish & Wildlife Service |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML060940315 (2) | |
Text
/home/kholland/Desktop/life history original/Birds_2004/B008.html Bald eagle Haliaeetus leucocephalus SPECIES CODE: B008 V01 STATUS:
Listed Threatened (32 FR 4001, 1967 March 11) in the conterminous United States.
SPECIES DESCRIPTION:
The bald eagle is the second largest North American bird of prey with an average 7-foot wingspan. It has a distinctive white head and white tail offset against a dark brown body and wings in adult birds. Females are about 25% larger than males; sexes are otherwise similar in appearance. Bald eagles are opportunistic foragers and diet varies across the range based on prey species available. They prefer fish, but will eat a great variety of mammals, amphibians, crustaceans, and birds, including many species of waterfowl.
REPRODUCTION AND DEVELOPMENT:
Bald eagles are monogamous and thought to mate for life unless one mate dies. Bald eagles build large stick nests lined with soft materials and nests are used for several years by the same pair of eagles. Nests measure up to 6 feet across and may weigh hundreds of pounds. Courtship and breeding vary by regions, for example, in Florida, breeding behaviors commence in September; in Ohio, breeding usually occurs in February. The average clutch size is 2 eggs. Young eagles can fly in 11 to 12 weeks, but the parents continue to feed them for 4 to 6 weeks while they learn to hunt. Bald eagles have lived up to 36 years in captivity.
RANGE AND POPULATION LEVEL:
The current range of the bald eagle includes all of the conterminous United States and Alaska.
The bald eagle is especially common in areas with large expanses of aquatic habitat, including Florida, Chesapeake Bay, Maine, and the Maritime Provinces of Canada, the Great Lakes and lake regions of Ontario, Manitoba, and Saskatchewan, northern California, Oregon, Washington, and coastal British Columbia and Alaska.
A wintering population survey of the total North American population was completed in 1997 and resulted in 98,648 individuals, with the largest number in Alaska (44,000) and British http://ecos.fws.gov/docs/life_histories/B008.html (1 of 2)04/03/2006 11:20:47 AM
/home/kholland/Desktop/life history original/Birds_2004/B008.html Columbia (28,507). The bald eagle was recommended for delisting in 1999 but it was determined that additional data would be needed before taking this action.
HABITAT:
The breeding range of the bald eagle is associated with aquatic habitats (coastal areas, river, lakes, and reservoirs) with forested shorelines or cliffs in North America. Throughout their range, they select large, super-canopy roost trees that are open and accessible, mostly conifers.
They winter primarily in coastal estuaries and river systems of the lower 48 states and Alaska, where thousands of bald eagles migrate each fall to take advantage of salmon-spawning runs.
PAST THREATS:
The decline of the bald eagle coincided with the introduction of the pesticide DDT in 1947.
Eagles contaminated with DDT failed to lay eggs or produced thin eggshells that broke during incubation. Other causes of decline included shooting, trapping, and poisoning.
CURRENT THREATS:
Loss of nesting habitat due to development along the coast and near inland rivers and waterways also has resulted in decreasing numbers.
CONSERVATION MEASURES:
LITERATURE CITED:
Buehler, D.A. 2000. Bald Eagle (Haliaeetus leucocephalus). In The Birds of North America No. 506 (A. Poole and F. Gill, eds.). The Birds of North America, Inc.,
Philadelphia, PA.
http://ecos.fws.gov/docs/life_histories/B008.html (2 of 2)04/03/2006 11:20:47 AM