Crescent Lake National Wildlife Refuge
Mountain-Prairie Region

Threatened Species

Bald Eagle (Haliaeetus leucocephalus)

Although the Bald Eagle was adopted as the United States National Emblem in 1782 bounties were paid for killing them as late as 1962. A declining population resulted in the National Emblem Law of 1940. Killing Bald Eagles was forbidden in the lower forty-eight states. It was another twenty-two years before it became illegal to kill them in Alaska.

The wide use of pesticides such as DDT after World War II increased the decline of the Bald Eagle population. The amount of toxins increase as they move up the food chain, especially in fish, the chief food source of Bald Eagles. The poisons resulted in the thinning of the eagle's egg shell, which caused them to crush under the weight of the incubating mother.

Photo of bald eagle - Photo credit: U.S. Fish and Wildlife Service

The ban on DDT in 1972 began the recovery of the Bald Eagle. Originally listed as Endangered in 1966 the Bald Eagle's status was dropped to threatened in 1996. Signs of the recovery included nests on both Crescent Lake and North Platte National Wildlife Refuges.

Bald Eagles began nesting on the refuge in 1994. Since then this first pair has produced an average of two eaglets annually.  This nest is located on Hackberry Lake, an area closed to the public.  A second pair initiated a nest on Crane Lake in 2003, and successfully fledged their first young in 2005. Both nests are still active on an annual basis. The eagles arrive in February and are incubating in March.  Eggs hatch in April and are fledged by mid-June.  In mid-July, as many southern breeding eagles do, the young and adults move north.  They will return for short times in the fall while migrating to their wintering grounds.


Photo of bald eagle - Photo credit: U.S. Fish and Wildlife Service

Last updated: March 21, 2011