The historical plight of bald eagles is told often. At its lowest point, surveys estimated the bald eagle breeding population was once as low as 500 nesting pairs in the lower 48 states. Unregulated taking by humans, loss of habitat and environmental contaminants were main factors in the eagle's population decline.
Bald eagles were not protected until Congress passed the Bald Eagle Protection Act in 1940, because of fears the nation's symbol was threatened with extinction.
While this ended legal indiscriminate killing, other factors also were working against bald eagles. In the 1950s, the pesticide DDT was widely used to kill insects that were destroying agricultural crops. According to a fact sheet on the U.S. Fish and Wildlife Service website, DDT and its residues washed into nearby waterways, where aquatic plants and fish absorbed it.
Bald eagles, in turn, were poisoned with DDT when they ate the contaminated fish. While the eagles didn't die from it, the chemical interfered with the ability of the birds to produce strong eggshells. As a result, their eggs had shells so thin that they often broke during incubation.
The U.S. Environmental Protection Agency banned the use of DDT in the United States in 1972, which helped get the bald eagle back on the road to recovery.
When the bald eagle was listed under the Endangered Species Act in 1978, North Dakota had no known nesting pairs and hadn't for quite some time.
Eventually, the eagle population started to expand and birds again started to establish nests.
In July 1999, the Fish and Wildlife Service proposed removing the bald eagle from the list of threatened and endangered species. In June 2007, the service announced the recovery of the nation's symbol and removal from the list of threatened and endangered species.
Through the early years of recovery in North Dakota, the state Game and Fish Department asked for simple reports of verified bald eagle sightings. The current bald eagle status no longer warrants reports of individual sightings, but Game and Fish biologists are still documenting active nests. Eagle nests are now observed in more than three-fourths of the counties in the state, with the total estimate at around 270.
Here's a link to report bald eagle nests in North Dakota:
Bald eagles start nest building in January and February, and they may reuse the same nest for many years. They typically lay one to three eggs in early to mid-March, and the eggs hatch in about 35 days.
By early July, the young will be nearly the same size as the adults and will venture out onto the branches in the nest tree and take their first unsteady flights. By the end of July or early August, the young are fully capable of flying and will leave (fledge) the nest.
However, the fledglings may remain in the general area of the nest, and the adults still may feed them for up to six weeks.