Bald Eagle

Haliaeetus leucocephalis
Original oil painting by Jay Drasher (ca. 1977) Photo by Bill Zemaitis (Bedford Co.)



The bald eagle (Haliaeetus leucocephalis) is federally listed as a threatened species (32 FR 4001, 1967 March 11) in the conterminous United States. Over the last several decades, bald eagles within the United States have experienced significant population increases. The 1990 USFWS Chesapeake Bay Region Bald Eagle Recovery Plan listed three bald eagle nesting areas, comprised of five nests, within the eastern half of Pennsylvania in 1989. According to the PA Game Commission (D. Gross, October 2006), the number of known eagle nests in Pennsylvania has increased to 116. Removal of the species from the Endangered Species List (i.e. delisting) appears to be quite possible in the near future. Even so, agency officials have indicated protection of this species will continue to be afforded under the Bald and Golden Eagle Protection Act (16 USC 668a-d, 1940 June 8, Amended 1978) and Pennsylvania wildlife code.

The bald eagle’s historical range extends over all of the continental United States, most of Canada, and northern Mexico. It lives in a wide variety of habitats. A very large bird, mature females have an average wingspan of 7 feet. It consumes a varied diet – including fish, smaller birds, rodents and other small mammals, and carrion. Individuals have been documented stealing prey items, usually fish, from other birds of prey. Nests are very large – up to 8 feet in diameter – and are normally constructed in a tall tree near a body of water. The average clutch size is between one and three eggs, although all hatchlings rarely survive to fledging. Sexual maturity is reached within 4 or 5 years.

The sight of this large raptor is increasingly common around larger water bodies throughout the region. As the population of bald eagles continues to grow, interactions between humans and the species increase. Once thought of as a species inhabiting only wild areas, some eagles are now accustomed to human activities and are nesting near developed areas. Construction projects that occur near potential bald eagle habitat may be required by the USFWS or PA Game Commission to conduct surveys for active nest sites. Aqua-Terra can conduct the appropriate scope of work for project conflicts involving bald eagles.