From the Facebook of: Wisconsin Department of Natural Resources

The 2025 American Birding Association Bird of the Year is…the common loon!

Wisconsin’s summer loon population is nearly 4,000 adults, most of whom reside in the northern part of the state.

However, you probably won’t see them at this time of the year, as loons travel to wintering habitats along southern shores. When loons return to Wisconsin and other northern states for the summer in a few months, they’re quite a sight. Their plumage is a bold pattern of white and black, and their most iconic feature is their deep red eyes.

But why this unusual feature?

Typically, a bird’s iris or eye color is related to age (adult vs. juvenile). This is the case in some raptors, and it is similar for loons. After hatching, their eye color is grey to brown, only starting to turn red during their first winter. After this, there is some change in eye color during plumage molts, so during the non-breeding season (October through February), the iris is red, but not the blood red we observe during the breeding season (March through September). There are subtle changes throughout the year as adult birds change plumage during breeding and nonbreeding season.

Some scientists speculate that the color allows them to filter red while hunting underwater. Or, like many bold bird characteristics, it helps them attract mates, affirm territory or signal maturity to other loons.