Bald Eagles — Are They Back?

Call it the "Eyrie Canal." In early March, employees of the Metropolitan Water Reclamation District of Greater Chicago taking samples along the Little Calumet River made a startling discovery. A large stick nest, or "eyrie," had been built in a tree along the shore. Soon employees of surrounding industrial companies became aware of a pair of bald eagles in the vicinity. The story quickly hit the press that eagles were nesting in the Chicago region for the first time in more than a century (the last recorded nesting was in the Indiana Dunes in 1897).

Since that time, the eagles have disappeared from the nest. According to John Rogner of the U.S. Fish and Wildlife Service, this indicates that the birds probably have not laid eggs. Once the female bald eagle begins laying eggs, she and the male take turns continuously incubating them in the nest for about five weeks. The pair has not been spotted in the area since the end of April.

Walter Marcisz, a native of the area and an experienced birder, thinks the eagles may have left because they are a young couple, not because of human interference. Bald eagles are often unsuccessful at their first nesting attempt, and these birds reportedly had some brown still on the white plumage of their heads, an indication that they are four to five years old (the age when breeding begins).

If given enough quietude and healthy habitat, bald eagles may become a more common occurrence in the Chicago Wilderness. After all, mated pairs can breed for decades and usually return to the same nest site year after year.

— Dan Spencer