Bald Eagle
Halaeetus leucocephalus
The bald eagle is a large sea eagle. It has a large, heavily built and strongly hooked bill, capable of tearing tough carrion flesh to small, bite-sized pieces. Its eyes have the ability to see great distances extraordinarily, sharper than a human's by 4 to 8 times. The eyes are fixed in their sockets, so the bird must turn its head while looking around. There are bony extensions that protect the eyes from injury when catching and handling its prey, also protecting them from the sun's glare. These extensions are called supra-orbital ridges. The eagle's spicules (special scales covering the soles of the eagles feet) help its talons catch slippery prey.
The adult bald eagle has a blackish-brown back and breast, a white head and tail, yellow talons and a yellow beak. It usually weighs anywhere from 6.6 to 13.9 pounds, is usually 30.4 to 36.4 inches long, and its wingspan is usually 5.5 to 8 inches. In the southern hemisphere, its mating season is from October to April, and in the northern hemisphere, from April to August, and its sexual maturity is reached in four years. It usually lays around 1 to 3 eggs, with an incubation period of about 35 days. The fledgling period is roughly 70 to 92 days, and the breeding interval is one year. The eggs are colored white with speckles and are the size of a goose's. It mainly eats fish and other seabirds. It can live for 47 years in captivity, and 25 years in the wild.
The bald eagle is related to nine other species of sea eagle found in the world, covering every continent except South America. Some of its related species are: Steller's sea eagle (Haliaeetus pelagicus), which has a massive bill used for feeding on salmon and is found along the coasts spanning from Siberia to Japan. There's also the white-tailed sea eagle (H. albibicilla), the largest eagle in Europe, whose range has been shortened due to habitat destruction.
Sometimes two chicks out of a litter will survive, occasionally due to the larger chick killing the smaller one. This will happen more often if the bigger chick is a female, as the females usually are bigger than the males. Should one try to kill the other, the parent or parents will not do anything to stop the fratricide. Newly hatched eaglets are soft, and grayish white, the can't walk because their legs are too weak to support them, and their eyes are partially closed, reducing vision. The only protection they have are their parents.
The way to tell a male from a female is by how their beak looks. The female's is usually deeper (stretching from the top of the beak to the chin) than the male's. Both genders are involved with the incubation period for the eggs, but the mother spends more time on the nest than the father.
The main causes for its endangerment are human persecution and pesticides. From 1917 to 1945 and from 1949 to 1953, bounty hunters in Alaska killed and estimated 140,000 birds. Use of the pesticide DDT in the 1960's and 1970's resulted in a 50 to 100% loss of breeding pairs in some areas. In the 1990's, however, the bald eagle has shown significant signs of recovery. There have been sightings of bald eagles in Cannelton, Indiana. It was spotted by someone in The Overlook restaurant across the river in Hawesville, Kentucky.
The bald eagle was chosen on June 20, 1782 as part of the emblem of the United States of America, because of its long life, great strength and its majestic looks. All states except Hawaii have been known to house a nest of bald eagles, and Alaska has the largest population. The birds were plentiful when settlers first came to America, but habitat destruction and uses of pesticides have caused the population of them to decline and by the 1960's, most states added it to their endangered species list. The problem with DDT is it would get on the eggs and make them brittle. Then when the mother sat on them, they would break. Sometimes the pesticide would cause the birds to be infertile (thus
incapable of breeding). People would hunt them for their feathers or because they thought the bird would take all the fish in the area. In 1995, they were taken off the endangered species list but declared threatened in the inner 48 states. There are more prevalent in Florida, Washington, Minnesota, Oregon, Michigan, and Wisconsin. Anyone caught killing one is fined $500,000 and must serve up to a year in prison.
The Migratory Bird Treaty Act and the Bald and Gold Eagle Protection Act protect the bald eagle, as well as many programs attempting to reintroduce the birds to their natural habitats, such as the American Eagle Foundation.
Resources:
1. "American Bald Eagle Information", (2003)
http://www.baldeagleinfo.com
2. "Ask Jeeves Kids" (2003)
http://www.ajkids.com
3. Wildlife Explorer, Publishers AB, IMPAB, printed in USA, International Masters IMP Inc., MCMXCVIII.
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