Public radio from Western Michigan University 102.1 NPR News | 89.9 Classical WMUK
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations
Second Friday of the month (third Friday in five-week months) at 6:45 am, 8:45 am and 5:44 pm. Why's That? explores the things in Southwest Michigan – people, places, names – that spark your curiosity. We want to know what makes you wonder when you're out and about.

Why's That: How many beavers live at Asylum Lake?

Lauri Holmes and Judy Gay stand on either side of a tree that has been half cut by beavers.
Cori Osterman
Lauri Holmes (left) and Judy Gay (right) stand on either side of a tree that has been half cut by beavers. Beaver mansion in the background.

Kalamazoo resident Judy Gay has frequented the Asylum Lake Preserve for years. Something that sparked her interest in the last few was the number of trees she’d seen felled by the lake’s beavers.

“Most of the trees around the lake were being taken down, and then I just began to wonder, how many beavers live here, how many beavers work on these trees? Is it just a couple, is it a whole huge family?” Judy asked.

This question brought us out to the preserve to meet with Lauri Holmes. She’s the co-chair of the Asylum Lake Preservation Association, and lives right next door to the preserve. It turns out Holmes and Judy go way back.

“We were potters and we were both in the same field before we retired,” Holmes said.

Dams allow beavers to spread water out and have more room to swim, forage and live. People sometimes treat beavers as a nuisance, as they take down so many trees and halt waterways.

But ALPA doesn’t fight them. Holmes says it’s very difficult and expensive to remove beavers. As soon as one family is relocated, another will surely take its place. So, ALPA finds it best to leave them be.

“And this is a preserve, and we are not its main occupants,” Holmes added. “Its main occupants are the plants and the animals that live here. And I guess that’s one of the reasons why a lot of us are really dedicated to the preserve, because it’s not a park. It reminds us of our place in the general scheme of things.”

Beavers generally build their homes and dams with soft wood as it’s easier to chew through. They also eat the sugary tissue layer of trees, called cambium.

The preserve's lakes and streams are lined with half-gnawed and felled trees. Almost every one is cut to fall toward the water, making transport a little easier.

Several fallen trees on Asylum Lake.
Cori Osterman
The number of fallen trees on Asylum Lake indicate that the beavers have been hard at work.

According to a book fittingly called Eager by Ben Goldfarb, Beavers don’t hibernate, instead spending the winter dragging morsels from their submerged larder of sticks and roots to the family waiting at home.

The beavers may be welcome on the preserve, but some of the neighbors want to protect its hardwood trees. Holmes and her husband Tom wrap the base of some oak trees to prevent the beavers from chewing them.

A tree on the edge of Asylum Lake with trunk wrapped in chicken wire.
Cori Osterman
Some trees on Asylum Lake are wrapped in chicken wire to prevent the beavers from taking them down.

“When beavers hear running water, they want to dam it up,” Holmes said.

And to stop the beavers from damming a creek that connects to Asylum Lake, the Holmes use a "beaver deceiver."

“What you do is, you fence it out, block it up and then have a pipe, which you can see down there, which runs way out into the bay and gathers the water and pulls it through,” Holmes said.

The beaver deceiver quietly carries the water from lake to river so the beavers don’t hear the running water and rush to block it off.

Walking around the preserve, we soon came upon what both our question asker and answerer call Beaver Mansion: a large, loosely dome-shaped structure that is about five feet tall and at least doubly wide. Holmes explains that its inhabitants carry mud and sticks in their mouths and plaster it together to create the spacious home.

A large pile of sticks plastered with mud sits on the edge of Asylum Lake.
Cori Osterman
The beavers live in the large pile of sticks plastered with mud on the edge of Asylum Lake, deemed beaver mansion.

“And there are rooms in there. There are rooms with food stored in them and rooms for having the babies and a room that’s maybe for entertaining friends, who knows.”

A David Attenborough video about beaver dwellings suggests that beavers hosting guests may not be too far off. Muskrats will provide fresh bedding for the lodge, possibly as a form of paying rent.

“Maybe that is why the beavers accept them and even allow them to share their food," Attenborough says.

Our question-asker Judy Gay wondered how many beavers live at Asylum Lake. While the exact number is unknown — beavers are nocturnal, so getting a count isn't easy — the effects they’ve had on the area suggest that there are more than just a few of them. Holmes jokes that it may be an extended family. And she speculates with our question-asker Judy Gay about the interior of Beaver Mansion: “I think once you're inside, you can move around in the different rooms."

“Maybe it has an attic too," Judy said.

“I wouldn’t be surprised."