Move over, lions, tigers, and bears. There’s a new apex predator in Chicago: the otter. Yes, those cuddly, playful water pups are deadly (at least to marine life) and calling Chicago their new home.

After having been driven out of the area for over a century, otters are making a comeback in the Chicagoland area. The Cook County Forest Preserve tags and tracks them, and has found some fascinating new behaviors for the species in an urban environment.

Worldview host Jerome McDonnell sat down with Chris Anchor, senior wildlife biologist with the Forest Preserves of Cook County and the head of the Urban Otter Project, to discuss the county’s otter and badger conservation efforts. Below are highlights from their conversation.

Jerome McDonnell: Tell us about the reentry of otters into this area, because they haven’t been here for a long time. But people started purposely putting them near here.

Chris Anchor: That’s correct. Otters disappeared about the turn of the last century along with many other charismatic species, and they were brought back on purpose. The states of Illinois, Iowa, Indiana, Missouri, Pennsylvania, they all negotiated to obtain otters from Louisiana. And they were released in the ’90s, and these otters that are found now in the Chicagoland area either originated from that stocking in the ’90s or they emigrated into the area from Indiana along the lakeshore or from Wisconsin down the Des Plaines River.

McDonnell: What happens when an otter gets into a pond? How does it go about its business?

Anchor: There’s almost nothing known about otters in an urban environment. We didn’t even think otters could survive in the Chicagoland area; we thought the water quality would be too poor to support them — and we’ve been completely wrong.

They’re completely opportunistic. And we’ve been able to document otters getting into a pond that we had been studying. As an example, when the otters came in [the Crabtree Nature Center out in Barrington], they very quickly in the matter of a couple of weeks eliminated whole age classes of turtles in that pond, along with a lot of the fish and frogs and tadpoles.

McDonnell: Somebody who is even rarer than a river otter seems to be is in the area: badgers. What are they like?

Anchor: They’re very, very low slung to the ground. Their legs are only two or three inches long, so they move at a very awkward, low-slung pace. They typically move at night, so most people would never see one, even if one was in the area.

The big thing about a badger is they dig very quickly, and they dig a lot of large holes — a foot, foot and a half across. And they’ll leave a mound of soil behind the hole that they just dug, that could be two or three feet in height. He is trying to dig out his food, and what he’s digging out is ground squirrels and woodchucks.

This interview has been edited for brevity and clarity. Click the “play” button to listen to the entire conversation.