Information About The Bald Eagle

The bald eagle is the symbol of the United States, and thanks to recovery efforts, its population is on the rise.

The bald eagle serves as the national bird of the United States, and is the only eagle native to North America.

DEFINITION

The bald eagle's scientific name is "Hallaeetus leucocephalus," which means "sea eagle with a white head." The word "bald" did not always hold the definition it does today. At the time the bird was named, "bald" meant "white" or "white-headed." The bald eagle is a member of the sea eagle family.

HISTORY

It is thought that as many as half a million bald eagles dotted North America before the first settlers arrived. There isn't a definite understanding as to why the eagle population declined, though many factors seemed to be at work. As more and more Europeans arrived, there were less and less bald eagles. Scientists note that the food supply of the eagle was reduced as more people began to hunt and fish the land, competing for the eagle's territory. As populations increased, the natural habitat of the eagle was destroyed, and the population took a serious hit in the late 1800s.

In 1940, the Bald Eagle Act was passed, making it illegal humans to harass the bald eagle. Even with the new Act in place, the eagle population continued to decline. When pesticides were introduced to crop life in the early 1900s, and inadvertently, to the eagle population, numbers once again faltered. Around this same time, more than 100, 000 bald eagles were killed in Alaska by fishermen, who feared they were a threat to the salmon population.

As the public slowly began to understand the eagle, many states placed the bald eagle on their lists of endangered species in the 1960s. In 1976, the Wildlife Service officially listed the bald eagle to its list of national endangered species.

Those studying the history of bald eagle, now tell us that there were many factors responsible for the eagle population's decline. These include fatal gun shot wounds, electrocution from power poles and lines, lead poisoning from eating hunting pellets, collisions with vehicles, starvation and exposure.

DESCRIPTION

Adult bald eagles have a blackish-brown breast and back. The head is bright white, as are the neck and tail regions. The bill and feet are both bright yellow in color. The female eagle is 34-37 inches, with a wingspan of 79-90 inches. Males are slightly smaller, measuring 30-34 inches, with a wingspan of 72-85 inches. Bald eagles weigh 10-14 pounds and are significantly larger than most of their eagle cousins.

Immature bald eagles are brown and white, with stark, black bills. As the bird matures, adult plumage develops. A bald eagle is considered mature at 4-5 years of age.

The large wingspan of this species enable bald eagles to do very little wing flapping or pumping. Eagles use "thermals," rising warm air currents to help them cover great distances while soaring. As the eagle flies, it spreads its tail feathers, in order to steer and maneuver itself in the air. The eagle's tail is also used to help with quick landings and stability when walking or swooping toward prey.



Bald eagles carry some 7,000 feathers from head to tail. Their feathers are lightweight, hollow, flexible and yet, very strong. It is the eagle's feather which protect the bird from inclimate weather, including excessive heat, cold winds and snow. Due to their sophisticated feather system, this bird is able to regulate its body temperature simply by changing the position of its feathers.

On the upper bill are two holes, from which the eagle breathes. Air passes through the eagle's lungs twice with each breath, which means that the eagle breathes at twice the rate of any other mammals. Bald eagles are very attune to their breathing, and never reach speeds or altitudes that would interfere with their breathing patterns.

The hooked bill of the bald eagle is used for tearing prey apart. The bald eagle also uses its beak as a weapon, a grooming tool and to feed the young. The beak of the eagle grows continuously during their lifetime. Eagles kept in captivity often have their beaks trimmed, whereas eagles in the wild have much longer and more prominent beaks.

Like the beak, the talons of the eagle grow constantly, as well. The eagle's talons are used as a defensive tool and also to kill and pick up prey.

As with all eagles, the bald eagle has excellent eyesight. With two centers of focus, this bird can see both forward and to its sides at the same time.

FEEDING HABITS

The bald eagle survives mostly on a diet of fish, though they will eat a variety of prey and carrion, including rodents, seals and small animals. Bald eagles do not need to feed every day, and have a pouch in their esophagus called a "crop," in which they store food.

LIFESTYLE

Bald eagles live in large, deep nests in tall trees, most often near waterways. A typical nest is 5-feet in diameter. The bald eagle returns to the same nest year after year, sometimes adding on to the nest so much, it exceeds 9-feet in diameter.

The mating season of the eagle varies by region. Bald eagles typically mate for life and can often be found traveling in pairs. The female eagle lays 1-3 eggs after copulation, and after a 35 day incubation period, the male and female share the responsibility of raising the young. A young bird will add one pound of body weight every 4-5 days. After the first 3 weeks of life, eaglets are 1 foot high and nearly adult size. As their primary feathers strengthen, eaglets make their first leap from nest to air. It's estimated that 40% of young eagles do not survive their first flight.

LIFE EXPECTANCY

Bald eagles living in their natural environment live 15-20 years, though birds as old as 30 years have been documented.

TODAY

As a result of recovery and reintroduction programs, today the bald eagle can be found over most of North America. There are an estimated 50, 000 bald eagles in the United States, 80-percent of which, are found in Alaska.

At this time, the U.S. Fish and Wildlife Service is proposing that the bald eagle be declared fully recovered. Even if it is deemed so, the bald eagle will remain protected by the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act.

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