At Asylum Lake Preserve in Kalamazoo, humans work to outsmart beavers — a welcome nuisance

Across Parkview Avenue from Western Michigan University’s college of engineering, a group of industrious engineers is hard at work in the university’s Asylum Lake Preserve.

Their ingenious creations have left some observers in awe. Others cringe at the litter of felled trees the workers already have created around the pristine lake.

But Tom Sauber, WMU Natural Areas Manager, says he’s supportive of the work of the family of beavers who have decided to move in, even as he works to outsmart them and limit the conflict between the animals and people who enjoy the quiet beauty of the preserve.

True, the beavers have taken down about 20 trees, and are working on more, in the year-and-a-half since they were discovered.

But, Sauber says, the rodents are simply  “altering the environment to fit their life. 

Observers watched as one tree after another was chomped down by they beavers.

“We took down thousands of trees across the road to build BTR (Business Technology and Research) Park 2,” Sauber says. “So who are we to say that the beavers are bad for the environment when in comparison they have only taken down a few trees to build their home and as a food source?”


The state of Michigan owes its history to the beaver, Michigan’s largest rodent.

It was the fur trade, after all, that sent French and English settlers in search of prized beaver pelts to supply Europe’s hat industry.

But fashion is fickle, beaver hats gave way to silk, and these days the beaver is known primarily for its size and amazing engineering feats, demonstrated in dams and lodges built out of logs, sticks, and mud. These days, the Michigan Department of Natural Resources classifies the beaver as “nuisance wildlife.”

That’s because beavers can cause problems when their tree-gnawing habits result in clear-cut swaths in a landscape being preserved for its beauty and serenity, such as the Asylum Lake Preserve’s 274-acre parcel of land.

But Sauber says the family of beavers on a small bay along the lake’s south shore has left a small footprint — a few trees down, and their lodge hasn’t created any flooding damage, often associated with their dam-building habits.

“They are the most amazing ecosystem engineers,” Sauber says, “and I marvel at their building skills. We need to live in harmony with them and understand that this is their home.”

Lauri Holmes, co-chair of the Asylum Lake Preservation Association, agrees.

She recently walked the Preserve with Bill Schneider, owner of Wildtypes, the company out of Lansing that has been working to remove invasive plant species in the preserve.  

“Bill is really an expert about plant ecology, and he was especially interested in the relationship of the downed trees, the work of the beavers, and the eliminating of the invasives that Wildtypes had been doing for so long,” Holmes says. “Bill was very pleased that the beavers have elected to live here. It means that the environment is healthy. He said that we should ‘revere’ them.”

Sharon Koole observed two beavers swimming at Asylum Preserve. The animals are not often seen during the daytime.

Holmes says Schneider pointed out that beavers eat softwood trees which will regenerate quickly, and that they will probably move on to a better food source when the food at the edge of the lake has been eaten. Beavers prefer alder, birch, cottonwood, maple, poplar, willow, and aspen, Sauber says — although there are no aspen trees this far south in Michigan.

“Botanically speaking, the real treasure of the preserve is the bounty of very old oak trees which grow on the uplands away from the lake's edge, Holmes says. “These, we really have to care for and preserve.”

Photographer Sharon Koole has found the beavers and their work fascinating subjects.

“I'm a regular walker at Asylum Lake,” Koole says. “I know that a lot of the trees are favorites, but it is really fascinating to see them downing the trees and the lodges getting bigger and bigger.”

Limiting the impact

Sauber says he has not actually counted how many beavers are living in the lodge they have built, but they typically have 6 to 7 and as many as 12 at any given time. 

Although he welcomes the animals, Sauber says he has taken some steps to limit their destruction. 

He has used some ingenious engineering of his own to trick the beavers into believing they don’t need to build any dams, for instance.

“In order to alter their behavior of wanting to build dams, we have placed a beaver deceiver at the culvert that connects Asylum Lake with little Asylum Lake, the area they would most likely pick to build a dam,” Sauber explains.

The rectangular device allows water to easily flow through but its presence at the juncture tricks the beaver into thinking there is already a dam in place, so they refrain from building there.

The Beaver Deceiver convinces the beavers that they do not need to build another lodge in this location.

The beaver deceiver has served its purpose well, Sauber says. “Occasionally they have placed a few branches to start a dam,” he says, “but it has ceased most of the dam-building activities.”

In addition, he says, he has considered placing cages around particularly desirable tree specimens in the area where the beavers are working to encourage the animals to chew elsewhere.

Because beavers live in and around the water, relocating the beavers to another part of the preserve is out of the question, and “at this point we have no intention of trapping and moving them anywhere,” Sauber says.

“They are a welcome addition to the ecosystem at Asylum Lake. People tend to forget that this is their home, not ours, and we need to live in harmony with them.”

Learn more

To learn more about these amazing animals, Sauber recommends reading “Eager Beavers Matter” by  Ben Goldfarb. 

“If we don't educate ourselves on the beavers we will never understand their rightful place in the environment.”

How to watch

Although the aftermath of beaver activity at the preserve has provoked interest on social media, the shy animals are nocturnal and difficult to observe in action. The best time to observe beavers at work is at dusk or dawn, however, they are very shy and tend to get spooked easily. People are asked to observe them in a respectful and quiet manner. 

“If you observe from a distance, focusing on their lodge with binoculars, you would have a better chance of seeing them without scaring them away,” Sauber says.

Asylum Lake Preserve

Asylum Lake Preserve is owned by Western Michigan University.

The lake and adjoining property lie in the West Fork of the Portage Creek Watershed. The land is preserved as a passive-use recreation area under an agreement between the City of Kalamazoo and WMU. Asylum Lake's preservation was ensured as a condition of the development of the College of Engineering on Parkview Avenue.

The property serves as a research area for professors and students of anthropology, biology, geography, hydrogeology, and environmental studies at WMU as well as other educational institutions. It is managed by the Asylum Lake Policy and Management Council, made up of representatives from local neighborhood organizations, environmental groups, and WMU departments. The preserve is part of the Landscape Division's Natural Areas Program.
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Read more articles by Rosemary Parker.

Rosemary Parker has worked as a writer and editor for more than 40 years, most of that time in Southwest Michigan.