Are you old enough to remember when the bald eagle was nearly extinct in the lower 48 states? If so, then you are perhaps one of many area residents who thrill at seeing the national symbol in the wild -- in treetops, soaring aloft or perched on the edge of the ice.
The December 2007 issue of the Wisconsin DNR magazine featured an eagle on the front cover, and the lead story, "Eagles soar back from the brink," is proof of an environmental success story.
According to the Wisconsin DNR Web site, bald eagles are found in the state year-round. Wisconsin supports the third largest breeding population in the 48 contiguous states, and in spring 2006, 1,150 pairs of bald eagles nested in the state.
Eagles from northern breeding populations migrate to this area while adult eagles from our state remain here most of the year. In winter, eagles congregate near open water, especially at dams and power plants on the Mississippi and Wisconsin rivers, including the St. Croix. Wisconsin's abundant lakes and streams provide habitat for a large population of breeding and wintering birds.
A history of their decline
A drastic decline in nesting bald eagles and the young they produced took place throughout the nation from the 1950s into the early 1970s. The decline was caused by habitat destruction and a build-up of DDE, a form of the pesticide DDT, in the fish and birds the eagles feed on. As they consumed this contaminated prey, DDE accumulated in the eagles and caused them to lay thin-shelled eggs that broke before hatching.
After the 1972 ban on the use of DDT, the number of nesting eagle pairs and their young in Wisconsin increased steadily.
Bald eagles were removed from the Federal Endangered Species Act's endangered and threatened species list in August 2007. Wisconsin's large and successful population played a significant role in the federal delisting.
To read the Wisconsin Natural Resources Magazine featured story, visit www.wnrmag.com/stories/2007/dec07/eagles.htm.