Bald Eagle (Haliaeetus leucocephalus)

Description: Majestic and proud, the bald eagle is well known as a national symbol and as a Whatcom County resident. When mature, bald eagles develop their recognized coloring of a brownish-black body, white head and tail, and yellow bill. Immature eagles have a dusky brown head and tail, a brownish bill, and blotches of white and cream on the body. As with most birds of prey, females are larger than males. Females reach a length of 43 inches, weigh about 15 pounds, and can have a wingspan of 92 inches. Males reach a length of 33 inches, weigh about 9.5 pounds, and can have a wingspan of 82 inches.

Distribution: The bald eagle is only present on the North American continent. In Whatcom County, popular places to see bald eagles include Drayton Harbor, the Nooksack River and the Lummi Flats.

Reproduction: Bald eagle nests are usually located on marine shorelines in Whatcom County, but are also located along rivers and lakes. Nests are often found in the tallest tree in the area, where the eagles have a good view of the surroundings. Bald eagles breed in the spring and typically lay a clutch of 2 eggs. The incubation period is between 31-36 days, during which the male and female eagles take turns keeping the eggs warm. After hatching, bald eagle chicks must be fed four times a day, so the parents must bring several pounds of food back to the nest daily to feed their young. Young typically leave the nest 8 to 10 weeks after hatching. Bald eagles mate for life, although they will take a new mate after one dies.

In the Whatcom County maps to the right, areas of significant importance to bird habitat are in red and blue dots indicate sensitive bird species nesting areas. This data was compiled by PSEP, NOAA, & EPA and mapped by Anchor Environmental.Click on each map for a larger image.

Ecology: Bald eagles are both hunters and scavengers. They hunt fish, waterfowl and mammals, and scavenge from elk, deer and whale carcasses and roadkill. Bald eagles are great hunters for several reasons. They have excellent eyesight; they can perceive depth and their ability to see details at a distance is 3 to 4 times greater than humans. Their razor sharp talons immediately contract upon contact with prey, and little spikes on the bottom of their feet make it easier to pick up slippery fish. Eagles’ bones weigh less than half the total weight of their 7,000 feathers, which makes it easier to gain altitude and glide as they search for prey. Food supply is the major dictator of bald eagle migration patterns. Pairs will migrate north in the early fall to get food in northern British Columbia and southeast Alaska. In the late fall, bald eagles from all over western North America migrate to Washington for the milder weather and food supply. When breeding season begins, bald eagles will return to their same breeding area and often the same nest each year.

Eagles display a variety of behaviors, mostly used as a form of communication between each other. During the winter, hundreds of bald eagles will often roost together in the night. The communal roosts occur in sheltered areas, helping the eagles conserve energy. These roosts may also serve a role in pair bond formation and communication about foraging sites.

Bald eagles are estimated to live at least 28 years in the wild; deaths at a younger age are usually directly attributable to humans or human activities.

Current Status:

Bald eagles in Washington have made a comeback from a recent low of 105 nesting pairs in 1980 to 605 pairs in 2001. During the winter months when bald eagles from all over western North America migrate to Washington, the population increases to about 4,500 bald eagles. When Lewis and Clark visited Washington 200 years ago, the estimated bald eagle population was between 6,000-10,000.

Several factors have contributed to the recent recovery of bald eagles, such as:

• Ban on the use of the pesticide DDT
• Protection of nesting and roosting habitat
• Reduction in shooting and harassment

The bald eagle is listed as “threatened” under the federal Endangered Species Act and at the state level by the Washington Department of Fish and Wildlife. The US Fish and Wildlife Service recently initiated a re-evaluation of the status of the bald eagle to determine if the species should be delisted. The bald eagle is also protected under the Bald Eagle Protection Act of 1940, Migratory Bird Treaty Act of 1918 and the Lacey Act.

Sources:
Gordon, D.G. 1991. The Audubon Society: Field Guide to the Bald Eagle.

Washington Department of Fish and Wildlife.
http://www.wa.gov/wdfw/
factshts/baldeagle.htm

http://www.wa.gov/wdfw/wlm/
diversty/soc/status/baldeagle/
finalbaldeaglestatus.pdf

For More Information: Whatcom County MRC
(360) 676-6876
http://whatcom-mrc.wsu.edu/MRC/index.htm