Bald eagles have overcome many challenges to their sustainability as a population. Service biologists are studying climate change effects on Michigan’s eagles. Photo: Tim Kaufman.
More than a half century of research has shown that bald eagles along Michigan’s shorelines and rivers are gradually beginning to nest earlier each season -- a potential indication of this iconic species’ response to changes in climate in the upper Midwest.
Bald eagles have overcome many challenges to the sustainability of their populations -- from loss of habitat to contamination of their food sources by pesticides and environmental contaminants.
National legislation banning the use of contaminants such as DDT and PCBs, coupled with habitat restoration in key portions of the eagle’s range, has resulted in a comeback for this beautiful raptor. More than 750 bald eagle pairs today fly the skies of Michigan, up from only 50 to 60 breeding pairs just half a century ago.
In 1961, University of Michigan graduate student Sergej Postupalsky began documenting bald historic and current eagle nesting sites and collecting banding data for the existing population in Michigan. Today, eagle research in Michigan spans state and federal agencies and academic institutions.
The result is more than 40 years of data on nesting, behavior, productivity, survival and overall population dynamics for bald eagles. It is safe to say the bald eagles of Michigan are among the most documented and well-monitored birds in North America.
More recently, Dave Best, fish and wildlife biologist at the U.S. Fish and Wildlife Service’s (Service) East Lansing Ecological Services Field Office, and Bill Bowerman, from the University of Maryland, have been studying bald eagles as indicators of water quality in the Great Lakes watershed of Michigan. The two have seen a trend in coastal bald eagle nesting patterns that may point to the effects of the changing climate.