ML070720437

Adw Haliaeetus Leucocephalus Information

ML070720437
Person / Time
Site:	Susquehanna
Issue date:	03/07/2007
From:	University of Michigan, Museum of Zoology
To:	Office of Nuclear Reactor Regulation
ALICIA MULLINS 301-415-1224
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- preview Home Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Aves Order Falconiformes Family Accipitridae Species Haliaeetus leucocephalus Haliaeetus leucocephalus (bald eagle)

Information Pictures Classification 2007/03/04 09:43:35.931 US/Eastern By Marie S. Harris Kingdom: Animalia Phylum: Chordata Subphylum:

Vertebrata Class: Aves Order: Falconiformes

Family: Accipitridae Genus: Haliaeetus Species: Haliaeetus leucocephalus Geographic Range The bald eagle is native to North America and originally bred from central Alaska and northern Canada south to Baja California, central Arizona, and the Gulf of Mexico. It

now has been extirpated in many southern areas of this range.

Biogeographic Regions:

nearctic (native ).Habitat Bald eagles are able to live anywhere on the North American continent where there are adequate nest trees, roosts ands feeding grounds. Open water such as a lake or an ocean, however, is a necessity.

Terrestrial Biomes:

desert or dune

savanna or grassland

chaparral

forest ; mountains

.Physical Description The plumage of an adult bald eagle is brown with a white head and tail. Immature eagles are irregularly mottled with white until the fourth year. Their legs are feathered half way down the tarsus, and the beak, feet, and eyes are bright

yellow. Bald eagles have massive tarsi, short and powerful grasping toes, and long talons. The talon of the hind toe

highly developed in both species, and it is used to pierce vital areas while the prey is held immobile by the front toes.

The wing span of an eagle can reach seven and a half feet .

Some key physical features:

endothermic

bilateral symmetry

.ADW: Haliaeetus leucocephalus: Information http://animaldiversity.ummz.umich.edu/site/accounts/information/Haliaeetus_leucocephalus.html (1 of 4)3/7/2007 11:12:28 AM ADW: Haliaeetus leucocephalus: Information Reproduction When the female is ready to copulate, she makes a head down, bowing gesture, and the male closes his talons and mounts her. The males's tail goes down and hers goes up. The process is completed when their cloacae meet. Bald

Eagles sometimes even copulate out of season. This behavior may account for the strong loyalty between mates. There is

not any sound evidence, however, that supports the idea that eagles mate for life.

A mated pair adds on to their nest each breeding year. The nests are primarily built of sticks and can eventually weigh up to two tons. Bald Eagle nests are among some of the largest nests in the world. Females lay a clutch of one to three

eggs, but usually two. Incubation lasts from five to six weeks. One problem that greatly hampers the recovery of the

species is sibling competition. A female lays her eggs a few days apart, and incubation begins with the first egg. One to

two days is the normal age difference between eaglets. Older hatchlings are able to dominate the youngers ones for food

because of their size. In a three-egg brood, the third chick has little chance of survival. Nest duties among the pair are

shared equally; both the male and the female will hunt and offer food to the eaglets.

Key reproductive features:

iteroparous

gonochoric/gonochoristic/dioecious (sexes separate);

sexual ; oviparous

.Behavior Bald eagles are only partially migratory; if they possess access to open water, they will remain at that nesting sight year round. Those that do not have access to water leave the frozen countryside in the winter and migrate to south or to the

coast. Eagles choose their migratory routes to take advantage of thermals, updrafts, and food sources, and usually

migrate during the day between 8:00 A.M and 6:00 P.M.

There are three methods of flight used during migration. Eagles ascend in in a thermal and then glide down, circle steadily down a stream of thermals, or use rising air generated by the wind as it sweeps down against a cliff or other

raised feature of the terrain.

Key behaviors:

motile .Food Habits Bald eagles are primarily fish-eaters that prefer salmon, but will also take avian prey. Waterfowl are an important secondary food source, and eagles also eat small mammals such as rabbits, seabirds, and carrion. When hunting, the

Bald Eagle either seeks its prey from a perch or from high in the sky, then swoops down and snatches up the prey in its

talons. Another method used by bald eagles to gain food is theft; Bald Eagles are often seen stealing prey from other

birds.Economic Importance for Humans: Negative There is no substantiated evidence that the Bald Eagle has any negative impact. In the past, however, the Bald Eagle has

been unjustly accused of hurting both the fish industry and the fur industry. As a result, the governement in Alaska once

paid two dollars for every dead eagle brought in. Soon after this went into affect, it became apparent that slaughtering

eagles didn't help the fish or fur industry. Another apparently false accusation is that they kill a large number of lambs on

open ranges.

Economic Importance for Humans: Positive Eagles help ranchers by controlling the number of rabbits and rodents -- animals that compete with livestock for grass.

Their feathers are used in the ceremonies of some groups of native North Americans.

Conservation Status IUCN Red List:

[link]: Least concern.

US Migratory Bird Act:

Over the years, the Bald Eagle population has suffered from excessive hunting and pollution. In the early part of the century, hunting eagles was a popular sport. Eagles

were shot not only for their feathers, but also because they posed a "threat" to livestock (e.g. sheep) and hampered the fishing industry. In recent years, however, pollution has http://animaldiversity.ummz.umich.edu/site/accounts/information/Haliaeetus_leucocephalus.html (2 of 4)3/7/2007 11:12:28 AM ADW: Haliaeetus leucocephalus: Information

[link]: Protected.

US Federal List:

[link]: Threatened

.CITES: [link]: Appendix II.

State of Michigan List:

[link]: Threatened.

greatly contributed to the demise of the species. As a result of both land and water pollution, a significant amount of the Bald Eagle food supply has been killed. In particular, the use of pesticides such as DDT had been the greatest threat to the species. Pesticides

are often found in fish, the major food supply for eagles. DDT in a female's body disturb

the shell-making process, causing her to produce very weak shells or no shells at all.

Eagles once numbered around 50,000 in the contiguous United States, but by the time

the U.S had restricted the use of DDT in1972, only about 800 bredding pairs remained.

Under the Endangered Species Act of 1973, however, the eagles have made a steady recovery. Breeding pairs now number close to 3000, and there has been an increase in the number of hatchlings per nest. Only in Canada and Alaska, however, are eagles found

in abundance.

A tremendous effort had been made to protect and restore the bald eagle population.

Some states now support effective nest-monitoring and programs to release young birds

into the wild. Federal protection has involved monitoring populations, improving

protection, setting up captive breeding programs, relocating wild birds, and establishing a wide-ranging public

information program.

Bald eagles are currently listed as threatened by the U.S. Fish and Wildlife Service and by the Michigan Department of Natural Resources. They are protected by the U.S. Migratory Bird Act.

Other Comments Much to Benjamin Franklin's dismay, the Bald eagle was adopted as the national emblem in 1782. He said that the Bald

Eagle was a bird of bad moral character (stealing food) and recommended the turkey instead. None the less, the bird

serves as a symbol of wilderness and freedom.

Bald Eagles are also considered to be higly adaptable birds. In one case, for example, a pair actually nested on a giant cactus.Contributors Marie S. Harris (author), University of Michigan.

References Gerrard, Jon, M.. et. al., The Bald Eagle: Haunts and Habits of a Wilderness Monarch. Smithsonian Institution Press,1984.

Mackenzie, John, P.S.. Birds of Prey. Paper Birch Press Inc., 1986.

Porteous, Peter, L.. National Geographic: Eagles on the Rise. 182(5), November 1992.

Savage, Candace. Eagles of North America. NorthWord Inc., 1987.

2007/03/04 09:43:36.658 US/Eastern To cite this page:

Harris, M. 2002. "Haliaeetus leucocephalus" (On-line), Animal Diversity Web. Accessed March 07, 2007 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Haliaeetus_leucocephalus.html.

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