The American bald eagle is no longer in danger of extinction, researchers report, as populations of the majestic birds continues to soar. Announcement of the growing health of the species was made on President's Day, February 16.
Bald eagles were first selected as the official mascot of the United States in 1782, due to the fact the species is native to North America, and possesses great strength and beauty, along with a long lifespan.
Biologists estimate there may have been 100,000 of the birds living in the wild at the end of the 18th Century. That number declined to dangerously low levels before they were placed on the Endangered Species List, and approximately 69,000 are alive today, according to researchers.
Despite a ban on commercial hunting provided by The Bald Eagle Protection Act of 1940, populations of the national bird began to steeply decline after World War Two, in part due to the overuse of the pesticide DDT. This chemical leaked into waterways, where it was absorbed by plants and fish, which were eaten by the birds. This caused the animals to lay eggs with thin shells that did not allow young to develop properly.
By 1963, there may have only been 487 nesting pairs of the birds in the continental United States. In 1967, the animals were placed on the Endangered Species List, until they were removed from those protections in the 1990's. The United States banned DDT in 1972, and Canada followed with a similar prohibition 17 years later.
The Winter Wings Bird Festival is held every President's day at the Klamath Basin National Wildlife Refuge bordering California and Oregon. Thousands of bald eagles and other birds come streaming into the region, seeking plentiful food and nesting areas. When populations of the eagles peak near the middle of February, visitors can see dozens of the animals together.
Some wildlife conservationists are concerned that, despite the progress made in population increases of bald eagles, the animals can still be threatened by habitat loss and interactions with human beings.
Silent Spring by Rachel Carson, a novel about the environment, was inspired, in part, by the loss of bald eagles and other birds to DDT. The pesticide, often mixed with fuel oil, was being sprayed from airplanes, over vast fields. The novel was the impetus for the environmental movement that gripped the country in the coming decades.
"It's hard to step away from the fact that they are our nation's symbol and knowing that they've now come back from the brink. I think a lot of people have a lot of pride that we managed to do that," Patti Barber, a game commission biologist in Pennsylvania, said.