ACADIA NAT’L PARK— Armed with waders, some two-by-fours, a few power tools and 6-inch wire mesh, Skip Lisle worked on Monday to build a beaver deceiver around a culvert under a bridge on the south side of Hodgdon Pond.
“This is a pretty perfect workday, no black flies, no mosquitoes,” said Lisle, vice president and founder of Beaver Deceivers based in Grafton, Vt. “I’m the only one in the world that builds authentic beaver deceivers. It’s very specialized just to build something that will survive the elements.”
Because Hodgdon Pond is part of Acadia National Park, Lisle began talking with park officials months ago about the problem of clogged culverts under a bridge that goes over a road leading to Long Pond.
“This was beginning to be threatened,” said Brian Henkel, project manager for Wild Acadia at Friends of Acadia, pointing to one of two culverts under the bridge. “Here we didn’t have any capacity [for water flow]. We were bumped up to the ceiling [with debris].”
Three to four feet of debris were removed from the culverts before Lisle could begin working to create one of his beaver deceiver structures around the opening to allow water to continue to flow underneath.
“They’ve been clogging like this since they returned,” said Lisle about the culverts, referring to how beavers neared extinction at the height of the fur trade in the 19th century. “I don’t think there’s anything more important than to keep them alive and keep them going.”
According to Henkel, there had been several previous attempts to prevent culvert clogging by the beavers in Hodgdon Pond.
“None of them really worked really well,” he added, noting how they were becoming a “potential threat to the infrastructure.”
Lisle, who earned a degree in wildlife management at the University of Maine in Orono a few years back, is passionate about diverting the attention of beavers from trouble spots in order to keep them alive versus killing them to resolve a problem.
“If you remove the beaver, it all just falls apart,” said Lisle, explaining how they are a keystone species. “I want society to start to shift its thinking. We’re just so in love with killing… You have to extirpate this native species from the culvert.”
Killing beavers doesn’t resolve the issue, he further explained. Another beaver will move into the same area and an endless cycle of killing and cleaning can go on without addressing the problem.
“Beavers are this marvelous creature, but they have this bad reputation for causing trouble,” said Lisle. “They only can dam in a very small area of the landscape, low gradient areas and small streams.”
As a child in Vermont, Lisle’s parents would bring him to local ponds around sunset to watch the beavers. Eventually, beavers moved to his family’s property and began clogging a culvert to a town road that ran through the property. Lisle found some of his father’s gardening fence and constructed the first of what has become his signature contribution to wildlife conservation and preservation.
“All my technology I’ve developed, they’re the best flow devices there are,” he said, pointing to a shallow area a short distance from the bridge that he is hoping the beavers will gravitate to instead. “I can’t control them. They have to cooperate.”
At the edge of the bridge, seeing to the bottom of the pond is easy because the water is so clear, despite Lisle and Henkel moving about.
“The reason the pond is so clean is because the beavers have been excavating it for so long there’s no soft stuff left,” Lisle explains. “They’re tremendous diggers, it’s amazing what they move if they get motivated.”
After graduating from UMO, he was hired by the Penobscot Indian Nation to address a culvert clogging problem that was prevalent on roads built for the forest products industry. It took several years and lots of research and development, but eventually Lisle came up with his signature framework that surrounds a flow pipe, typically extending out from the culvert, with wire mesh around it to prevent beavers from building in a flow area.
“It has to be big and it has to be sophisticated for it to have a chance to work,” he said about the beaver deceivers that he builds by hand. “This is a manageable problem. We can eliminate this problem.”