Pennsylvania Field Office
Northeast Region

Bald Eagle Biology and History

Haliaeetus leucocephalus

STATUS: Not listed under the Endangered Species Act; Protected under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act.. Both Acts protect bald eagles by prohibiting killing, selling or otherwise harming eagles, their nests or eggs.

DESCRIPTION: Bald eagles may weigh up to 14 pounds and have seven-foot wingspans. They are typically identified by their white heads and tails, however, they don't attain this characteristic plumage until five years of age. In their fourth year, bald eagles almost look like adults but have a narrow black line behind the eye and often have a dark band on the tip of their tail. Until that time, they are dark brown with varying amounts of white mottling so they can be confused with Golden Eagles.

RANGE AND POPULATION LEVEL: Bald eagles are found throughout North America.

HABITAT: Bald eagles typically occur in the vicinity of aquatic ecosystems; they frequent lakes, reservoirs, large rivers (e.g., Delaware River, Juniata River, Susquehanna River), and wetland systems. Their nests are usually built in large trees within two miles of these features. Because eagles are vulnerable to human disturbance, particularly during the nesting season, nests are often located in relatively remote forested areas.

  Status and Federal   Protection
  National Eagle   Repository
  Northeast Region
  Eagle Guidelines
  Biology and
  Life History
  National Management
  Final Environmental
  Definition of Disturb
Last updated: September 24, 2010
All images by FWS unless otherwise noted.