As people settled throughout the Western half of the United States, some bald eagle habitats were destroyed in the process. Eagles prefer not to live near humans, instead selecting tall, mature trees near water for nesting. Because the bird of prey's diet may include livestock such as chicken and lamb, some farmers and ranchers hunted bald eagles to protect their farms [source: U.S. Fish and Wildlife Service].
The bald eagle (Haliaeetus leucocephalus) population received the biggest blow from the environmental prevalence of a chemical pesticide called Dichloro-diphenyl-trichlorethane (DDT), which seeped into freshwater supplies. This meant that fish swimming in the polluted waters would absorb the chemical. From there, eagles would ingest the fish and effectively consume the poison. Once in their bloodstreams, DDT caused females to produce eggs with shells too thin to protect the embryo. Since the hatchlings couldn't survive, the number of bald eagles shriveled accordingly. Rachel Carson's 1962 book "Silent Spring" about DDT's harmful environmental effects helped bring about the ban on the pesticide's use in 1972.
In 1967, bald eagles were added to the endangered species list. That designation offered the eagles more habitat protection from development and made it illegal for anyone to kill them. The U.S. Fish and Wildlife Service headed the repopulation efforts through programs like breeding a colony in captivity at the Patuxent Wildlife Research Center in Maryland [source: U.S. Fish and Wildlife Service]. By monitoring the growth of that group of bald eagles and eventually releasing them into the wild, the species began to rebound. The agency divided the country into five regions to manage the revitalization [source: U.S. Fish and Wildlife Service]. Then, in 1995, the government transferred bald eagles in the lower 48 states from endangered to threatened classification. Threatened status means that a species is no longer in immediate danger of extinction but still needs protection.
Although they were designated as threatened, strict rules regarding the eagles' habitats persisted. For instance, the general rule for building around an eagle nesting site is that it can't come within a 330-foot (100-meter) radius [source: Slevin]. That restriction hampered Minnesota resident Edmund Contoski's plans to develop his lakefront property. Frustrated, he filed a federal lawsuit in 2005 challenging the restriction [source: Slevin]. Contoski won his case on the basis that the eagle's population had reached a level where it no longer should be considered threatened, paving the way for the eagle's removal from the endangered species list.
On June 28, 2007, the Interior Department officially declared the bald eagle to be fully recovered and delisted. At that time, an estimated 9,789 breeding pairs lived in the continental United States, representing one of the most dramatic population improvements for an endangered or threatened species [source: U.S. Fish and Wildlife Service]. Major conservationist groups including the National Resources Defense Council and the National Wildlife Federation approved of the motion as a celebration of the conservation efforts. There have been a few setbacks for this bird of prey recently, as Arizona's U.S. District Court reversed the delisting for bald eagles in that region, reclassifying the Sonoran Desert bald eagle as a threatened species [source: U.S. Fish and Wildlife Service]. However, the U.S. Fish and Wildlife Service maintains protectionist policies to help ensure that the remaining bald eagle population doesn't plummet.
More Great Links
- "Bald Eagle." U.S. Fish and Wildlife Service. Updated June 2007. (Aug. 11, 2008)http://www.fws.gov/species/species_accounts/bio_eagl.html
- "Bald Eagle Recovery: Questions and Answers." U.S. Fish and Wildlife Service. June 2007. (Aug. 11, 2008)http://www.fws.gov/migratorybirds/issues/BaldEagle/Bald%20Eagle%20Final%20Q&As.pdf
- "Benjamin Franklin FAQ." The Franklin Institute. (Aug. 11, 2008)http://www.fi.edu/franklin/birthday/faq.html#21
- "Desert Bald Eagle Returns to Endangered Species List." U.S. Fish and Wildlife Service. May 1, 2008. (Aug. 20, 2008) http://www.fws.gov/news/NewsReleases/showNews.cfm?newsId=A4C4116B-F819-28C1-B8DCE55F7D9C5976
- Roach, John. "Bald Eagles Soar Off Endangered Species List, But Will Act Be Weakened?" National Geographic News. June 28, 2007. (Aug. 11, 2008)http://news.nationalgeographic.com/news/2007/06/070628-bald-eagles.html
- Slevin, Peter. "Bald Eagles to Be Taken Off Endangered List." Washington Post. Dec. 25, 2006. (Aug. 11, 2008)http://www.washingtonpost.com/wp-dyn/content/article/2006/12/24/AR2006122400666_pf.html
- Webley, Kayla. "Bald Eagle Leaves Endangered Species List." NPR. June 28, 2007. (Aug. 11, 2008)http://www.npr.org/templates/story/story.php?storyId=11504430