Once listed on the state 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 state Department of Natural Resources staff show a record number of nesting bald eagles, with 1,695 nests occupied by breeding adults. That figure topped the nesting total of the previous year by 105.
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.
Ten nests were recorded in Eau Claire County, 11 in Chippewa County and 12 in Dunn County.
Buffalo County is especially bald eagle friendly, Jaskiewicz said, because of its many miles of shoreline along the Mississippi River, its ample woods that provide eagle perches and its largely undeveloped, rural nature.
“Bald eagles love the Mississippi,” she said, noting counties along that 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. Bald eagles were removed from the state endangered species list in 1997 and the federal list in 2007. Eagles and their nests have federal protection via the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act.
Steve Betchkal, an Eau Claire birding expert, said northern Wisconsin’s plentiful water, large trees and relatively undeveloped territory make it among the best locations in the world to view eagles. Locally, bald eagles have nests in such locations as Putnam Park in Eau Claire, Lake Hallie Golf Course and River Prairie Park in Altoona.
“We’re kind of spoiled now,” he said, noting eagle sightings, once rare, have become more common in the wake of added protections for the birds.
Bald eagles are among people’s favorites to view, he said, because “they are impressively large, striking birds.” Females, typically larger than males, can have 8-foot wingspans.
“They are the most impressive birds to watch in the air,” Betchkal said.
Jaskiewicz and Betchkal said they hope bald eagle numbers continue to climb. But they worry continued development could reduce available habitat for the birds. In addition, Jaskiewicz said, some eagles are struck by vehicles on roadways as they feed on prey.
Betchkal said he is concerned climate change could reduce the number of large trees in Wisconsin, thereby forcing bald eagles from the state.
“I worry their (population) growth is going to hit a wall because of climate change and urban sprawl,” he said.
For now, bald eagles continue to thrive, providing viewing pleasure for many. Eagles have proven to be adaptable, Jaskiewicz said, and 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.”