The bald eagle is the national bird of the United States of America. In 1782, the Continental Congress adopted the design for the Great Seal of the United States depicting a bald eagle grasping 13 arrows and an olive branch with its talons. It appears on most official seals of the U.S. government, including the presidential seal, the presidential flag, and in the logos of many U.S. federal agencies.
The bald eagle is a bird of prey found in North America. A sea eagle, it has two known subspecies. It can be found in most of Canada and Alaska, all of the contiguous United States, and northern Mexico. It is found near large bodies of open water with an abundant food supply and big trees for nesting. The bald eagle is usually quite sensitive to human activity while nesting, and is found most commonly in areas with minimal human disturbance.
Once a common sight in much of the continent, the bald eagle was severely affected in the mid-20th century by a variety of factors, among them the thinning of egg shells attributed to use of the pesticide DDT. Other factors in bald eagle population reductions were a widespread loss of suitable habitat, as well as both legal and illegal shooting. In 1930 a New York City ornithologist wrote that in the state of Alaska in the previous 12 years approximately 70,000 bald eagles had been shot. Many of the hunters killed the bald eagles under the long-held beliefs that bald eagles grabbed young lambs and even children with their talons, yet the birds were innocent of most of these alleged acts of predation. In 1984, the National Wildlife Federation listed hunting, power-line electrocution, and collisions in flight as the leading causes of eagle deaths.
The species was first protected in the U.S. and Canada by the 1918 Migratory Bird Treaty, later extended to all of North America. The Bald and Golden Eagle Protection Act, approved by the U.S. Congress in 1940, prohibited commercial trapping and killing of the birds. The bald eagle was declared an endangered species in the U.S. in 1967. Perhaps most significant in the species’ recovery, in 1972, DDT was banned from usage in the United States.
Later, the eagle population rebounded. The bald eagle can be found in growing concentrations throughout the United States and Canada, particularly near large bodies of water. In the early 1980s, the estimated total population was 100,000 individuals. The U.S. state with the largest resident population is Alaska, with about 40,000–50,000. The species was removed from the U.S. government’s list of endangered species in 1995 and transferred to the list of threatened species.
The bald eagle is an opportunistic feeder which subsists mainly on fish, which it swoops down and snatches from the water with its talons. It builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal species, up to 4 m deep, 2.5 m wide, and 1000 kilos in weight.
Bald eagles are not actually bald; the name derives from an older meaning of the word, “white headed”. The adult is mainly brown with a white head and tail. The sexes are identical in plumage, but females are about 25 percent larger than males. The beak is large and hooked. The plumage of the immature is brown. The bald eagle has a typical wingspan of between 1.8 and 2.3 m and normally weighs between 3 and 6 kg.
The call consists of weak staccato, chirping whistles, somewhat similar to a gull’s call.
The bald eagle is a powerful flier, and reaches speeds of 56–70 km/h when gliding and flapping, and about 48 km/h while carrying fish. Its dive speed is between 120–160 km/h, though it seldom dives vertically. It is partially migratory, depending on location.
The average lifespan of bald eagles in the wild is around 20 years, with the oldest confirmed one having been 38 years of age. In captivity, they often live a bit longer.
The bald eagle is a sacred bird in some North American cultures, and its feathers, like those of the golden eagle, are central to many religious and spiritual customs among Native Americans. Eagles are considered spiritual messengers between gods and humans by some cultures.
Current eagle feather law stipulates that only individuals of certifiable Native American ancestry enrolled in a federally recognized tribe are legally authorized to obtain or possess bald or golden eagle feathers for religious or spiritual use.
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