The Bald Eagle
An Overview by the U.S. Fish and Wildlife Service
TITLE: The Bald Eagle
AUTHOR: U.S. Fish and Wildlife Service staff
SOURCE: U.S. Fish and Wildlife Service. Two federal agencies, the United States Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS), administer the Endangered Species Act.
PERMISSION to publish not needed.
The bald eagle is an Endangered Species Act success story. In the mid-1900s, our national symbol was in danger of extinction throughout most of its range. Bald eagles were decimated by habitat destruction and degradation, as well as illegal shooting and the contamination of their food source by the insecticide dichlorodiphenyltrichloroethane, known as DDT.
Habitat protection afforded by the Endangered Species Act, the federal government’s banning of DDT, and conservation actions taken by the American public have helped bald eagles make a remarkable recovery. Bald eagle sightings are now a common occurrence in many parts of the country.
When America adopted the bald eagle as the national symbol in 1782, anecdotal accounts stated that the country may have had as many as 100,000 nesting eagles. The first major decline of the species probably began in the mid to late 1800s, coinciding with the decline of waterfowl, shorebirds and other prey.
Although they primarily eat fish and carrion, bald eagles used to be considered marauders that preyed on chickens, lambs and domestic livestock. Consequently, the large raptors were shot in an effort to eliminate a perceived threat. Coupled with the loss of nesting habitat, bald eagle populations declined.
In 1940, noting that the species was threatened with extinction, Congress passed the Bald Eagle Protection Act, which prohibited killing, selling or possessing the species. A 1962 amendment added the golden eagle, and the law became the Bald and Golden Eagle Protection Act.
Shortly after World War II, DDT was hailed as a new pesticide to control mosquitoes and other insects. However, DDT and its residues, washed into nearby waterways, where aquatic plants and fish absorbed it. Bald eagles, in turn, were poisoned with DDT when they ate the contaminated fish. The chemical interfered with the ability of the birds to produce strong eggshells. As a result, their eggs had shells so thin that they often broke during incubation or otherwise failed to hatch. Other pesticides related to DDT are suspected to have caused increased mortality, in addition to DDT’s harmful effects on reproduction. By 1963, with only 417 nesting pairs of bald eagles known to exist, the species was in danger of extinction.
In 1967, the Secretary of Interior listed bald eagles south of the 40th parallel under the Endangered Species Preservation Act. In 1972, as the dangers of DDT became known - in large part due to Rachel Carson’s book Silent Spring - the Environmental Protection Agency took the historic and, at the time, controversial step of banning the use of DDT and some related pesticides in the United States.
Following enactment of the Endangered Species Act, we listed the species in 1978 as endangered throughout the lower 48 states, except in Michigan, Minnesota, Oregon, Washington and Wisconsin, where it was designated as threatened. The species was not listed as threatened or endangered in Alaska because populations there have remained robust.
Listing the species as endangered provided the springboard for working with our partners to accelerate the pace of recovery through captive breeding programs, reintroduction efforts, law enforcement and nest site protection during the breeding season.
In July 1995, we announced that bald eagles in the lower 48 states had recovered to the point where those populations previously considered endangered could be reclassified to the less critical category of threatened.
Then in 2007, we estimated there were at least 9,789 nesting pairs of bald eagles in the contiguous United States. Bald eagles staged a remarkable population rebound and recovered to the point that they no longer needed the protection of the Endangered Species Act. On June 28, 2007, we announced the recovery of our nation’s symbol and removal from the list of threatened and endangered species.
Bald eagle populations throughout the country continued to rise with an estimated 2009 population in the lower 48 states of 72,434 individuals, including 30,548 breeding pairs. Estimates for the bald eagle population in the lower 48 states, based on data from 2018 to 2019, total 316,700 individuals, including 71,467 breeding pairs.
The recovery of the bald eagle is one of the most well-known conservation success stories of all time. We continue to work with our partners in state and federal agencies, tribes, nongovernment organizations and private landowners to ensure that our nation’s symbol flourishes.
Even though bald eagles were delisted from the Endangered Species Act in August 2007, because their populations recovered sufficiently, bald eagles are still protected under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act. Both laws prohibit killing, selling, or otherwise harming eagles, their nests or eggs.