A Congress of Eagles
There was a time, not so long ago, when catching a glimpse of a majestic bald eagle, the United States' national symbol, would have been a rarity. The widely-used pesticide, DDT had rendered the birds' eggshells paper-thin, and fewer and fewer of the creatures hatched every year. But with the 1967 classification of Haliaeetus Leucocephalus as an endangered species and the 1972 ban on the dangerous chemical, the recovery of this magnificent raptor began. In some places, the numbers of birds are still quite low. But, in others, from Alaska to Missouri, a combination of factors have brought the magnificent raptors to roost in incredible numbers. In these areas, it's often quite easy to see great numbers of soaring birds stretching their magnificent wings as they search for food, which is why birders are also flocking to these places.
Food is the primary factor that brings these birds together in great concentrations. At certain times of year, thousands of bald eagles congregate along rivers and streams in Washington, Alaska, and Montana where spawning salmon, eulachon, or shad make easy prey. In the winter in certain parts of Illinois, Missouri, Nebraska, Oregon, Wisconsin, and Wyoming, any water that remains unfrozen draws eagles from miles around, where they feed on wintering waterfowl and fish swimming near the surface.
By nature, bald eagles tend more toward scavenging than toward catching healthy prey, and they require a relatively large amont of food. They often eat spawned out or weakened fish, and sick or dying waterfowl, although they are capable of being formidable predators when necessary. It is easy to recognize the mature bald eagle by its distinctive plumage. After the bird reaches four or five years old, it loses its mostly brown feathers and sports a white cap and tail. Bald eagles have a wing span of about seven feet and weigh about 14 pounds on average, although the female of the species is usually a little larger. Eagles mate for life, and females lay two three-inch eggs each spring. The birds can live to be about 40 years old.
Details mentioned in this article were accurate at the time of publication