CHICAGO (CBS) — Improving conditions and a milder winter have led to increased sightings of bald eagles in mean bald eagles are visible in several western suburbs.

Their 7-foot wingspans make bald eagles easy to see, and they have been spotted recently in Elgin, Yorkville, Oswego and St. Charles.

Mason Fidino, an ecological analyst with the Lincoln Park Zoo’s Urban Wildlife Institute, said the birds of prey have also been spotted closer to the city.

“They’ve even been seen within Cook County itself, along some of the rivers next to Chicago,” he said.

Bald eagles haven’t been on the endangered species list since 2007, and don’t really have any predators.

“They kind of are at the top of the food chain, so the things that have actually driven down their populations have pretty much just been humans,” Fidino said.

He attributed the increased bald eagle sightings in the Chicago area to the mild winter, leaving lots of open water where the birds of prey can hunt for fish.

“It just seems like eagles have been sort of traveling around, and just trying to look for new foraging opportunities along any large rivers that they possibly can,” Fidino said.

If you don’t have luck in the wild, the Lincoln Park Zoo has one named Ethan on loan.