Northern Prairie Wildlife Research Center
Bald eagles are thought to have historically nested in all of the lower 48 states. In North Dakota, they were apparently common along the Missouri and Red Rivers, and at Devils Lake and the Turtle Mountains.
It's estimated that 50,000 breeding pairs occupied the lower 48 states in pre-colonial times. By the 1960's, only 400 pairs occupied this area.
The decline in bald eagle numbers was due to loss of habitat, shooting, trapping, and the heavy use of pesticides such as DDT. DDT became a major problem in the 1950's and 1960's as it accumulated in the food chain and caused eagle eggs to thin and be crushed under the weight of the incubating adult. DDT is now banned in the U.S.
Bald eagles prefer forested habitats near bodies of water. In North Dakota, this equates to the stretch of Missouri River between Bismarck and the Garrison Dam where open water during winter months provides a source of food. Nesting bald eagles are not common, however, an active nest was also reported on this stretch of river from 1989-1994. During March of 1995, 40 eagles were observed feeding on dead fish on the Lewis and Clark WMA near Williston.
Adults mate for life and tend to use the same nest year after year. Nests are usually at the top of tall trees and can weigh more than 2,000 lbs.
Usually two eggs are laid and hatch after about 35 days. Both parents feed the young a combination of fish, waterfowl, small mammals, and carrion.