Bald Eagles

An adult bald eagle sits on a rock outcropping next to sage brush

Bald eagles are one of more than a dozen raptor (birds of prey) species in Yellowstone. The peregrine falcon and bald eagle are recovered endangered and threatened species.

NPS/Peaco

 

The bald eagle (Haliaeetus leucocephalus) was named the national symbol of the United States by Congress in 1782. Found near open water from Mexico to Alaska, bald eagles may range over great distances but typically return to nest in the vicinity where they fledged. In Greater Yellowstone they feed primarily on fish, but also on waterfowl and carrion. Numbers declined dramatically during most of the 1900s due to habitat loss, shooting, and pesticide contamination. In 1967, the US Fish and Wildlife Service listed the bald eagle as an endangered species in 43 states, including Idaho, Montana, and Wyoming. Habitat protection, restrictions on killing, and restrictions on pesticide use led to population growth and delisting of the species in 2007. Bald eagles nesting in northwestern Wyoming are part of the Rocky Mountain breeding population that extends into Idaho and Montana. Learn More: Bald Eagle Information Continued...

 

Quick Facts

Number in Yellowstone

  • In 2014, park staff monitored 18 active bald eagle nests.
  • Of the 18 active nests, 10 (56%) were successful.
  • 16 young were produced. Productivity for active nests in 2014 (0.89 young per nesting female), was greater than the 31-year average (0.7).

Identification

  • Large, dark bird; adult (four or five years old) has completely white head and tail.
  • Females larger than males, as is true with most predatory birds.
  • Immature bald eagles show varying amounts of white; they can be mistaken for golden eagles.

Habitat

  • Habitat can be a clue to which eagle you are seeing.
  • Bald eagles are usually near water where they feed on fish and waterfowl. They also nest in large trees close to water.
  • Golden eagles hunt in open country for rabbits and other small mammals.
  • Exception: Both feed on carcasses in the winter, sometimes together.

Behavior

  • In severe winters, eagles may move to lower elevations such as Paradise Valley, north of the park, where food is more available. On these wintering areas, resident eagles may be joined by migrant bald eagles and golden eagles.
  • Feed primarily on fish and waterfowl, except in winter when fish stay deeper in water and lakes and rivers may be frozen. Then they eat more waterfowl. Eagles will also eat carrion in winter if it is available.
  • Form long-term pair bonds.
  • Some adults stay in the park year-round, while others return to their nesting sites by late winter.
  • Lays one to three eggs (usually two) from February to mid-April.
  • Both adults incubate the eggs, which hatch in 34 to 36 days.
  • At birth, young (eaglets) are immobile, downy, have their eyes open, and are completely dependent upon their parents for food.
  • Can fly from the nest at 10–14 weeks old.
  • Some young migrate in fall to western Oregon, California, and Washington.
 

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