Once listed on the state and federal endangered species lists, bald eagles continue a strong comeback as the bird's population numbers in Wisconsin are soaring.
Nesting surveys conducted last year by the Department of Natural Resources show a record number of nesting bald eagles, with 1,695 nests occupied by breeding adults. That was 105 more than the previous year.
The total is significantly higher than in 1974, the first year surveys were conducted. At that time, just 108 nests were documented statewide.
"Bald eagles have made a remarkable comeback in Wisconsin," said Laura Jaskiewicz, a DNR research scientist who coordinates the statewide survey effort.
The birds' success is also evident by another measure. For the first time since surveys began, nests were recorded in 71 of Wisconsin's 72 counties, with Milwaukee County the only place with none.
"It's exciting to see bald eagles in virtually every part of our state," Jaskiewicz said.
Vilas and Oneida counties in far north-central Wisconsin are home to the highest number of nests statewide, with 172 and 154, respectively, DNR figures show.
Bald eagles prefer to nest in tall trees along waterways, and those counties have among the highest number of freshwater lakes in the world.
In the 12-county west-central region, Buffalo County was home to the greatest number of nests, with 65 recorded last year. The next-highest nest concentration was in Barron County, with 27, followed by Pierce County, 25, and Trempealeau County, 22.
Buffalo County is especially eagle-friendly, Jaskiewicz said, because of its many miles of Mississippi River shoreline, its ample woods that provide eagle perches and its largely undeveloped, rural nature.
"Bald eagles love the Mississippi," she said, noting that counties along the river tend to have high eagle populations.
The record number of nests documented this year is the result of protections afforded by state and federal endangered species laws, declining levels of DDT in the environment and the efforts of the DNR and others to monitor the birds. Jaskiewicz said eagles have found success in areas where they previously were rare.
"Bald eagles are proving to be adaptable," she said. "That's good, because people really love their eagles."
