The bald eagle, with its snowy-feathered (not bald) head and white tail, is the proud national bird symbol of the United States—yet the bird was nearly wiped out there. For many decades, bald eagles were hunted for sport and for the "protection" of fishing grounds. Pesticides like DDT also wreaked havoc on eagles and other birds. These chemicals collect in fish, which make up most of the eagle's diet. They weaken the bird's eggshells and severely limited their ability to reproduce. Since DDT use was heavily restricted in 1972, eagle numbers have rebounded significantly and have been aided by reintroduction programs. The result is a wildlife success story—the U.S. Fish and Wildlife Service has upgraded the birds from endangered to threatened.
Bald eagle numbers in the U.S. were estimated to be between 300,000-500,000 in the 1700s. Numbers were once as low as 500 nesting pairs in the lower 48 states. Bald eagle numbers have rebounded since and now the lower 48 states boast over 5,000 nesting pairs. There are a total of about 70,000 bald eagles in the whole of North America (Including Alaska and Canada).