Record number of bald eagle nests

A record number of bald eagle nests were found statewide in 2018.

Wisconsin’s bald eagle population continues to reach new heights as 2018 nest surveys revealed a record number of nests statewide and Walworth County confirmed its first documented nest in at least a half century, according to results released in the 2018 Wisconsin Bald Eagle Nest Survey.

“2018 was another great year for the bald eagles’ remarkable comeback in Wisconsin,” said Laura Jaskiewicz, the Department of Natural Resources research scientist who coordinates the statewide aerial survey effort. “The number of nests is still increasing throughout the state and we now have them documented in 71 of 72 counties.”

The 2018 surveys found a total of 1,695 bald eagle nests occupied by breeding adults, an increase of 105 nests from 2017. That’s a 6.6 percent increase and more than 16 times as many nests found in the first detailed surveys in 1974, when bald eagles were listed as state and federally endangered species and only 108 nests were documented.

As in past years, Vilas County with 172 nests and Oneida County with 154 nests had the highest totals. Bald eagles prefer to nest in tall trees along water, and these two counties have some of the highest concentrations of freshwater lakes in the world.

“It doesn’t seem like we’ve hit any ceiling yet,” Jaskiewicz said. “Eagles are still finding places to nest, some continuing in the same nests for many years and some new ones popping up here and there.”

Citizen reports Walworth County nest

While the aerial nest surveys were conducted in March and April by DNR conservation biologists and DNR pilots, the nest documented in Walworth County was reported by a private citizen. Sharon Fandel, a DNR district ecologist with the Natural Heritage Conservation program, went to the site and confirmed the nest.

Fandel put out a call last year for residents to report potential bald eagle nests in southeastern Wisconsin.

“Citizen reports were a big help this past year. There were a handful of reports that helped confirm new nests while other reports identified nests that we didn’t know about previously,” Fandel said. “It’s great that so many people are interested in eagles and their continued success and population expansion in the state. It would not surprise me if we learn of other new nests in southeastern Wisconsin in 2019.”

Confirming the Walworth County nest means that Milwaukee County remains the lone county in the state without a known active eagle nest. Fandel said the heavily developed nature of Milwaukee County means there is relatively little bald eagle nesting habitat available (when compared to surrounding counties) and that it is less likely a nest will be documented there.

“That being said, it’s certainly not impossible. In areas like the Twin Cities metro area of Minnesota, bald eagles are doing quite well and the Minnesota DNR has documented dozens of active nesting territories,” said Fandel.

It’s a testament, at least in part, to the species’ adaptability, she added. Depending on the individual bird(s), some appear to be more accustomed or tolerant to human activity.

“Time will tell if eagles stake their claim in Milwaukee County, but if Minnesota’s ‘urban’ eagle population is any indication, there’s certainly a precedence to suggest it could be on the horizon for Milwaukee,” Fandel said.

People who have seen new, small nests can report them by searching the DNR website, dnr.wi.gov, for bald eagle watching and click on the link on the right hand navigation column for “Report a plant or nongame animal.”

The record number of nests documented this year results from protections under the state and federal endangered species laws, declining levels of DDT in the environment, and DNR and partner efforts to help monitor and aid recovery. Bald eagles flew off the state endangered species list in 1997 and the federal list in 2007; eagles and their nests are still federally protected under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act.