ENDANGERED SPECIES
Status: Federal Endangered
State Endangered

BALD EAGLE
(Haliaeetus leucocephalus )

Description 

The scientific, English and Lakota common names for this species all refer to the white head of the adult. The Lakota name, anukasan , means "white on both sides." The adult bird is easily identified by its white head and tail. Adult bald eagles are barrel shaped with brown to black body feathers and a body length of 31 to 37 inches (79 to 94 cm.). The wingspan of a mature bald eagle can be up to eight feet (2.4 meters) across. Immature bald eagles, called wambli gleska (spotted eagle) by the Lakota, have dark brown plumage mixed with white and don't have the distinctive white head. Birds develop the contrasting white head and tail and yellow beak of the adult in their fourth or fifth year.

Distribution 

Bald eagles are widely distributed throughout the United States and Canada. They winter in open valleys in the Black Hills, in the lakes area of northeastern South Dakota, and along the Missouri River and its tributaries. Winter roosts of eagles are especially common below the reservoir dams from Pierre to Yankton. Although historically bald eagles nested in southeastern South Dakota, there have been no confirmed nesting records in the state during this century. In the spring of 1992, a pair began nesting in Sand Lake NWR in Brown County in northeastern South Dakota, but abandoned their nest before laying eggs.

Natural History

Bald eagles have nested in most of North America. They construct nests in tall mature trees surrounded by smaller trees that serve as a buffer. Because the nests are reused and added to year after year, they can reach enormous proportions. The largest recorded nest was almost 20 feet (6.1 meters) deep and 10 feet (3 meters) across. Eagles build their nests between 10 (3 meters) and 180 feet (45.7 meters) above ground, with most nests between 30 and 60 feet from the ground. Females usually lay two eggs that hatch within 35 days. Bald eagles prefer areas of open water and can almost always be found near a water source. They eat carrion , fish, waterfowl, and small mammals.

Because of its fierce appearance, the bald eagle was chosen in 1782 as a symbol of the United States. However, the birds are, in reality, very timid, often abandoning their nests when disturbed by people.

Significance

The feathers of golden and bald eagles are sacred to American Indians as symbols of God and the values the people hold toward nature and humanity. Because eagles represent power and strength, their feathers adorned the clothes of great Lakota and Dakota leaders with each feather representing a courageous deed. People are presented with eagle feathers in recognition of actions that bring benefit or honor to the Lakota people. The Lakota and Dakota people believe that eagle feathers possess spirit and power and are the closest connection people can have to God.

The eagle is honored in an eagle dance performed by men wearing eagle feathers in their hair and carrying fans made from eagle tail feathers. This dance is still performed at many powwows today. Whistles made from the bones of eagles are used in the Sun Dance, the most sacred ceremony of the Lakota and Dakota people. As the national symbol of the United States, the bald eagle is of immeasurable value as an example of our American heritage. Conservation of the bald eagle serves as a reminder of the success people can have in saving endangered species.

Conservation Measures

In the 19th century the number of nesting bald eagles was already beginning to fall in some states due to human development and disturbance of nesting areas. Their precipitous decline in the mid 20th century was due in a large part to DDT residue build up in fish, upon which the eagles fed. Collisions with power lines and lead poisoning from eating pellet-contaminated carrion added to the species' losses. When DDT was banned, the population of the bald eagle rebounded. Unfortunately, loss of habitat and nesting areas and illegal hunting still endanger the species.

Strict guidelines to manage and protect existing bald eagle populations have been implemented by federal and state conservation agencies. One effective measure establishes buffer zones around eagle nesting areas to help minimize disturbance from humans. It is illegal to disturb bald eagles when they are nesting. It is also a federal offense to shoot, trap, or harm these birds in any way. The National Wildlife Federation offers a reward of $500 for information leading to the conviction of anyone who kills a bald eagle. Even possession of eagle feathers is illegal except for those American Indians who obtain a permit to have the feathers for religious ceremonies.

To reduce the number of eagle deaths from collisions with power lines, power companies have made structural modifications to their facilities.

Glossary


Carrion - decaying flesh of dead animals.

DDT - "dichlorodiphenyltrichloroethane" is an organic compound of hydrogen, carbon and chlorine that was widely used as a pesticide until people realized it was accumulating in the environment because it wouldn't breakdown for many years. DDT use in the U.S. was banned in 1972.

References


Ashton, Diane E., and Eileen M. Dowd, 1991. Fragile Legacy: Endangered, Threatened and Rare Animals of South Dakota. S.D.
Department of Game, Fish and Parks Wildlife Division. Pierre, SD.
Baptista, Luis and Joel Carl Welty, 1988. The Life of Birds. 4th Edition. Saunders College Publishing, New York.
Cooper, Ann, 1992. Eagles, Hunters of the Sky. Denver Museum of Natural History. R. Rinehart Publishers, Niwot, Colorado.
Erlich, Paul, David Dobkin, and Darryl Wheye, 1988. The Birders' Handbook. Simon and Schuster, New York.
South Dakota Ornithologists' Union, 1991. The Birds of South Dakota. 2nd Edition. NSU Press, Aberdeen, SD.
World Wildlife Fund, 1990. The Official WWF Guide to Endangered Species. Beacham Pub. Inc., Washington, D.C.

Selected Resources for Teachers


A Home for Pearl, a video for loan from the S.D. State Library, S.D. Curriculum Center, or S.D. Game Fish and Parks offices.
1991, grades K-4.
American Bald Eagle, a 16 mm film showing eagle life cycle, behavior, and conservation, for loan from S.D. State Library,
#C00114. 1971.
Eagles for Kids a picture book by Charlene Gieck, 1991. North Word Press, Inc. Minocqua, WI., grades K-6.
Eagles, Hunters of the Sky, a Story and Activities. by Cooper 1992. Denver Museum of Natural History. Robert Rinehart
Publishers, Niwot, Colorado, grades 3-6.
Eagles, Zoobook Series by Wildlife Ed. Ltd. San Diego, CA 92103, grades K-6.
Last Stronghold of the Eagles, a 16 mm film showing eagles in Alaska, for loan from S.D. State Library, #D00032. 1981.
The Book of Eagles by Helen Sattler. Lothrop, Lee and Shepard, 1990, grades 5-8.
We Care About Eagles slide and tape show by National Wildl. Fed., Washington, D.C., grades 4-12.

Written by:
Stacey Jones and Dr. Erika Tallman, Northern State University, Aberdeen, SD 57401. 1992.

Reviewed by:
Dr. David Swanson, Biology Department, USD, Vermillion, SD 57069.
Dr. Dan Tallman, Northern State University, Aberdeen, SD. 57401.

The distribution map was reproduced from The Fragile Legacy with permission from the S.D. Dept. Game, Fish &Parks.
Illustrations provided by the S.D. Dept. Game, Fish &Parks.

Publication of the Bald Eagle fact sheet was funded by Prairie Pothole Joint Venture of the North American Waterfowl
Management Plan.