Bald Eagle Facts | Canadian Rockies Wildlife Guide
In the 1950s and 1960s, scientists figured out that the pervasive use of DDT after World War II as an insect-control measure was causing a thinning of the shells of bald eagles and other birds. This, combined with habitat loss, led to the bald eagle being listed as endangered. In 1973, inspired by the influential book Silent Spring by Rachel Carson, legislation banning the use of DDT was passed. These two legal moves—listing the eagle as endangered and banning DDT—were the first steps on the road to recovery for the bald eagle.
Down listed from endangered to threatened in the lower 48 states in 1995, a few years later this magnificent raptor was found secure enough to remove from the endangered species list altogether.
Today a new threat is placing these majestic birds at risk. Lead bullets and pellets used for hunting deer, birds and other animals pervades their environment and nearly half of all bald eagles throughout the United States have toxic levels of lead in their bloodstreams. Recent studies estimate that their reproduction rate is decreasing by 4% per year. Fortunately, alternatives to lead ammunition are available and hopefully more hunters will choose less-toxic options in order to protect these birds that are an important symbol of wilderness.