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Bald Eagle Recovery
(Released August 1999)


Review Article

The American bald eagle (Haliaeetus leucocephalus), once near extinction, has made such a powerful comeback that the U.S. Fish and Wildlife Service has proposed to remove it from the List of Threatened and Endangered Wildlife. For more information, visit

When settlers first arrived in North America, the bald eagle population was estimated to have been between 250-500,000. As the United States grew as a nation, the bald eagle population declined through the 1940's. This was due to human persecution of the bald eagle and loss of nesting habitat. In 1940, the Bald Eagle Protection Act (16 U.S.C 668) was passed, prohibiting killing or selling of bald eagles. This Act increased public awareness of the bald eagle and resulted in a partial recovery or a slower decline of the species in most areas of the country.

By the 1950's, organochlorine pesticides such as DDT were in general use. DDT was initially used to control mosquitoes along coastal and wetland areas and later was used as a general insecticide. DDT accumulated in individual bald eagles that ate fish contaminated with DDT. The pesticide caused the birds to lay eggs that had very thin shells, resulting in widespread nesting failures. Loss of nesting habitat continued to contribute to the population decline.

In 1963, the bald eagle population was down to 417 nesting pairs in the continental United States. In 1967, the Secretary of the Interior listed bald eagles south of the 40th parallel as endangered under the Endangered Species Preservation Act of 1966. At that time, Alaskan and Canadian populations of bald eagles were not considered endangered.

During the 1960's, scientists recognized that DDT was largely to blame for the bald eagles' problems. But it wasn't until 1972 that the Environmental Protection Agency banned the pesticide in the United States. The next year, the Endangered Species Act of 1973 (16 U.S.C. 1531-1544) was passed.

Following the enactment of the Endangered Species Act, nationwide surveys of the bald eagles revealed that the eagle population throughout the lower 48 states was declining. As a result, the U.S. Fish and Wildlife Service listed the bald eagle as endangered except in Michigan, Minnesota, Oregon, Washington and Wisconsin where it was designated as threatened.

The Endangered Species Act defines an endangered species as a plant or animal that is in danger of extinction. A threatened listing means a species could become endangered in the foreseeable future. The main goal of the Endangered Species Act is to restore endangered and threatened species of animals and plants to a level where they are again viable, self-sustaining populations. The Act contains provisions for listing, protection, and especially recovery of imperiled species. It identifies, describes, and schedules the actions necessary to restore endangered and threatened species to a more secure biological condition.

Seventeen years after being placed on the Endangered and Threatened Species list, the bald eagle population had increased from the 417 nesting pairs in 1963 to 4500 nesting pairs in 1995. The bald eagle was reclassified in 1995 from endangered to threatened as a result of the significant increase in numbers of nesting pairs, increased productivity and expanded distribution. The improvement was a direct result of the banning of DDT and other persistent organochlorines, habitat protection, and from other recovery efforts, such as captive breeding programs, reintroduction efforts, law enforcement and the protection of nest sites during the breeding season.

On July 6, 1999, the U.S. Fish & Wildlife Service published in the Federal Register their proposal to remove the bald eagle from the List of Endangered and Threatened Wildlife. According to the Endangered Species Act, a species may be delisted if the best scientific and commercial data available can substantiate that the species is neither endangered nor threatened. Before a species can be removed, the following five threats to its wellbeing must be addressed:

  1. present or threatened destruction, modification, or curtailment of the species' habitat or range
  2. over-utilization of the species for commercial, recreational, scientific, or educational purposes
  3. disease or predation
  4. inadequacy of existing regulatory mechanisms
  5. other natural or manmade factors affecting its continued existence

If the bald eagle is delisted, it will still receive protection under the Migratory Bird Treaty Act, the Bald and Golden Eagle Protection Act (which is the successor to the Bald Eagle Protection Act of 1940), and many state wildlife laws. The Endangered Species Act requires the Fish & Wildlife Service to monitor recovered species for at least 5 years following delisting. Should an unexpected decline in species numbers occur, the bald eagle could be relisted as threatened or endangered.

Written by Amy L. Forrester, M.A.

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