Yellowstone National Park - Bald Eagle

Behavior

In the summer, bald eagles eat mostly fish and waterfowl. Their fishing skills, however, are not as polished as those of the Osprey and they have been watched on numerous occasions harassing these fisher birds until they drop their catch and fly off leaving the fish on the ground for the eagle to scavenge. During winter months they feed primarily on waterfowl and carrion. It is not uncommon to see bald eagles feeding on an elk carcass along side ravens, magpies, golden eagles and coyotes.

Yellowstone Data

In 1995, the U.S. Fish and Wildlife Service downlisted the Bald Eagle from endangered to threatened due to significant population gains made over the last three decades. Certain specific populations, however, are not completely recovered due to heavy metal contamination problems in the Great Lakes region, and habitat encroachment and development problems associated with riparian zones in the desert southwest.

In Yellowstone National Park, a total of 14 eaglets fledged from 26 active nests during 1999. Nest substrate instability, a result of the 1988 Yellowstone wildfires, caused minimal problems for nesting pairs; however, in following decades we expect large numbers of trees to topple to the ground. This will undoubtedly result in nest failure, loss of nest sites, and sudden changes in the locations of nesting territories. Although it has occasionally been documented that Bald Eagles will take over previously occupied Osprey nests, the incidence of takeover appears to be increasing due to the competition for nest sites. In 1999 alone, two previously known Osprey nest sites were occupied by Bald Eagles.