In the late 1960s, a survey by the U.S. Fish and Wildlife Service (USFWS) found fewer than 500 breeding pairs of bald eagles in the lower 48 states of the United States. The bald eagle, which has been the national bird of the United States since 1787, nearly went extinct due to hunting and poisoning as a pest species because of the birds’ impact on poultry farmers, and agriculture practices in the first half of the century. And now their population is soaring and the species is an environmental regulatory success story.
DDT, a powerful insecticide widely used in the 1940s and ‘50s, was a particular hazard to bald eagles and all raptors; at the top of the food chain, they consumed a massive concentration of the toxin through their prey. It resulted in thin-shelled eggs that couldn’t be safely incubated or hatched.
In 1972, DDT was banned. In 1973, the Endangered Species Act was made law, and bald eagles were included on the list of most protected. It became illegal to so much as own a bald eagle’s dropped feather, and a federal crime to disturb a nest.
Their recovery since the ‘70s is a tribute to how well robust conservation efforts can work. From 500 breeding, the population has exploded. A 2020 USFWS survey found more than 71,000 nesting pairs. The population is four times what it was only 12 years ago, when it was last surveyed in 2009. In 2007, bald eagles were removed from the Endangered Species list.
According to the National Audubon Society, however, the success in restoring the bald eagle population is a statistical outlier in the grander scope of bird species. Studies show that in terms of total population, bird numbers in North America are approximately two-thirds what they were in the 1960s. Not only that, but two-thirds of currently living bird species may be at risk of extinction if the global average temperature continues to rise.