The American mink is equally at home on land or in the water. And despite its size, is not to be trifled with. (Jan Den Ouden / Pixabay)

The Chicago River is due for a spring cleaning on Saturday.

Friends of the Chicago River is hosting its annual Chicago River Day cleanup, with volunteers fanning out from Lake County to Calumet to clear litter and trash from sites along the waterway, as well as the Calumet River.

Registration is required to take part in the activities. Although a number of locations have already reached their volunteer capacity, plenty of sites are still in need of helpers. On the map below, green and blue “pins” indicate places where volunteer slots are still open.

While the water’s health is improving, litter remains a persistent problem, according to Friends. Picking up trash immediately improves the environment for people, plants and animals. 

One of those creatures is this year’s River Day mascot, and no, it’s not any of the usual suspects.

The American mink is the poster critter for River Day 2021.

These nocturnal, solitary members of the weasel family live on the shores of rivers, streams, lakes, ponds and marshes. Equally at home on land or in the water, they can easily climb trees and are capable of swimming underwater for 100 feet.

Though relatively small — typically 18-28 inches long, weighing 2-3 pounds — mink can take down much larger prey such as rabbits.

Indeed, wild mink are not to be trifled with. According to Wildlife Illinois, a project of the Illinois Department of Natural Resources, the mink is the top predator in Illinois’ aquatic food web and its presence indicates a functional food chain.

Because they’re not active during the day, mink aren’t frequently seen by people, which is possibly for the best, lest humans mistake the thick-furred animal for a cute, cuddly creature. They’re actually quite aggressive, even with each other, and, similar to skunks, minks can unleash a foul smelling liquid from their scent glands when scared or excited.