Butting Heads With Beavers

Dec. 6, 2004 — -- Rod Barker liked his new neighbors. They attracted other interesting neighbors, provided entertainment and were, in Barker's opinion, very "cute." The problem is their construction work leads to perpetual flooding in his basement.

"I've gone downstairs and found a foot and a half of water," said the Collinsville, Conn., resident. "Something had to be done."

Barker, like a growing number of Americans who live in rural areas, has a beaver problem. Ever since the animals settled into nearby Rattlesnake Brook and dammed the waters to create a cozy home, Barker's house has become flooded and he has lost prized trees to the rodents' impressive teeth.

It used to be that beavers were a threatened species in the United States. Beaver pelts were treasured commodities often used to make hats and were even traded as currency in parts of the frontier. By the 1930s, the industrious animals had nearly been wiped out by trapping.

But a combination of trapping restrictions, a reforestation of farmland and a decrease in value of beaver pelts has fostered a dramatic comeback among beaver populations to the point that wildlife officials in some states are thinking trapping restrictions may not have been a great idea.

In Massachusetts, for example, wildlife officials have noted a more than threefold jump in beaver populations from 20,000 to 70,000 since a 1996 ballot measure banned the use of lethal traps. In recent years voters in three other states -- Arizona, California and Colorado -- have passed similar measures.

State legislators have done the same in Florida, New Jersey and Rhode Island. In Oregon, trappers killed about 2,700 beavers in 2003, down from 10,000 or more annually in the 1980s when pelt prices were higher than today's standard cost of $14.

Chrissie Henner, a fur bearer biologist for the Massachusetts Division of Fisheries and Wildlife, says voting records show people who voted for the 1996 measure were largely from urban areas where, she says, there can be a general ignorance of the potential conflicts between growing populations of beaver and people.

"The higher the populations, the higher the density, the more chances of conflict with people," said Henner. "That's what people don't realize and the danger is that people start perceiving the animal as a pest."

Natural Builders

But even people annoyed by beavers usually can't help but be impressed by them. The rodents are well-known for their ability to topple large trees using only their specially adapted four front teeth. A lone beaver can chew down hundreds of trees each year. Their teeth never stop growing, and they are self-sharpening thanks to a hard enamel on the front and a soft enamel on the backside of the tooth.

The animals gnaw down trees to get at their bark, which is the mainstay of their diet, along with twigs, leaves and other vegetation. Once the bark is gone, the beavers use the logs to build lodges and dams to create their homes, which have special, underwater entrances.

And research has shown that beavers are actually a boon for ecosystems. Scientists have found their industrious dam-building fosters healthy aquifers and attracts other wildlife.

The pools of water created by their constructions provide a place for water flow to slow down, which allows sediment to settle and keep out of waters flowing downstream. Their dams and mounded homes of sticks and mud also tend to create bends in streams that would otherwise run a straighter course and deepen over time.

"As the channels cut down, the water sinks and you lose your water table," explained Michael Pollock, a scientist with the National Oceanic Atmospheric Administration in Seattle who has studied how beavers help mold river basin ecosystems. "Sometimes letting nature run its course is the best way to maintain land."

Studies in the southern United States have shown that fish, including salmon, thrive in beaver ponds, as do water birds such as ducks and herons. Even Barker, who has had to invest in a basement sump pump to clear his basement, feels conflicted about the beavers.

He enjoys watching a population of mallard ducks and a great blue heron that have flocked to the soggy terrain by his home. But the Connecticut Department of Environmental Protection plans to trap and kill the beavers that are causing flooding at Barker's and other nearby homes. Barker had hoped there would be another option, but was told that beavers are highly territorial and relocation generally doesn't work since the animals will fight newcomers to the death over terrain.

Outsmarting Beavers

As beavers and homeowners continue to clash, some have specialized in devising alternative ways of dealing with the animals and their problematic constructions. Mike Callahan of Beaver Solutions in Hadley, Mass., custom-builds fence and piping systems in and around beaver dams to alleviate flooding problems.

"These kinds of systems have been used for decades to resolve beaver problems," said Callahan. "But they're usually not designed properly. We guarantee ours work."

Callahan's fences, which cost about $750 with installation, are custom-designed to prevent beavers from building dams around road culverts. His multiple pipe systems, which run around $1,000, are threaded through beaver homes and drain a dam once waters reach above a certain level. Callahan claims the techniques usually work better than trapping and killing the animals since more beavers rediscover the area sooner or later and set up another dam.

"Trapping has its place, but it's not the best method," he said.

Henner argues that a combination of controlled licensed trapping and anti-flooding devices like Callahan's should be used to establish harmony between beavers and people.

As for Barker, he admires the animals, but also values his trees -- and basement.

"One morning when I was on my deck feeding the ducks, a beaver came within 20 feet of me and sat on a tree root and looked at me," Barker recalled. "I thought, 'I wish I could get you to eat cracked corn and bread instead of my trees.' Then maybe we could make this work."