Beavers continue to be a nuisance when not trapped

All of nature is controlled by correlations that, for the most part, are observed only by trained eyes. The excavations of pileated woodpeckers, for example, often are used by tree-nesting ducks such as hooded mergansers, wood ducks, and common goldeneyes – “whistlers” if you’re a duck hunter. Likewise, the denning behavior of bears relates closely to the availability of beechnuts, and a boy addicted to fishing quickly learns the connection between beavers and brook trout. Hence, we come to the subject of this column.

There was a time – and it wasn’t so God-awful long ago – when Mother Nature pretty much managed her own affairs hereabouts. Accordingly, the workings of beavers, specifically dams, created ponds and flowages that not only benefited wildlife and the environment but often produced prime brook trout fisheries. Times, however, have changed. Nowadays, because of social pressures resulting in reduced trapping activity, beaver populations are burgeoning.

Although man is referred to as the most dangerous and efficient predator, he is, nonetheless, a part of nature. Granted, human dependency on hunting, fishing, and trapping for survival has greatly diminished. But it is fact that those controlled pursuits are important to fisheries and wildlife management. In conjunction with that, Scott Roy, a fisheries biologist assigned to the Department of Inland Fisheries and Wildlife’s Region E, pointed to the beaver problem in his recent summary of the Moosehead Lake fishery.

“Natural reproduction of brook trout and salmon at Moosehead Lake and many of the region’s other waters is being held hostage to the whims of the fur market. The market has been affected by an increasingly vocal group of people protesting trapping. In years past, we looked at the lake’s spawning tributaries with little concern that access into the streams was a problem.

“Occasionally we encountered a beaver dam, but usually the major streams were clear. As natural fur products have become less popular, the price of pelts has dropped, causing many trappers to give up. In recent years, with less trapping pressure, beaver populations in this area seem to have increased dramatically.” Roy and his coworkers have noticed new dams on many of Moosehead’s tributaries.

“Many of the dams flooded important spawning habitats or totally blocked access to upstream habitats,” the biologist reported. “On one stream, Squaw Brook, the presence of three beaver dams explained why we found no salmon reproduction in the past two years. Adult brook trout from the lake were also denied access into Squaw Brook.” Roy allowed there were many streams that couldn’t be checked. But because of the increase in beaver-related problems, he assumed there were access problems in those tributaries.

In conclusion, he wrote: “This fall we breached the dams that we had located, some several times. The Wildlife Division helped remove the dams and moved the beavers from Squaw Brook. Years ago, many of the remaining dams would have washed out in the spring. With today’s low trapping interest, most of the nuisance beaver will survive the winter with their dams intact.

“They will then pose a potential threat to successful access into the streams in the spring when smelts spawn. Unless trapping pressure increases, we expect the magnitude of the problem to grow. We will work with the regional wildlife personnel to develop a more aggressive strategy to address the nuisance beaver problem. Access to spawning habitat is critical to maintaining wild populations of brook trout and salmon in Moosehead Lake.”

The problem also extends to anadromous fish, particularly Atlantic salmon, which spawn in brooks and streams. Ken Beland, a biologist with Maine’s Atlantic Sea-Run Salmon Commission, reports that beaver populations have increased on some Down East rivers and their tributaries. Consequently, the potential for salmon spawning habitats being flooded by dams is increasing. Obviously, spawning habitats, where water flows, depths, and temperatures are critical, are integral to the rivers’ salmon-restoration programs.

Beland allowed beaver dams were an even greater problem in obstructing upstream migrations of adult salmon: “When the rivers are low there is no spillage coming over the dams. The water simply strains through them, which doesn’t do the salmon any good. Also, debris from the dams often extends so far downstream that it’s impossible for the fish to make a jump.”

Without question, beaver populations will increase for as long as trapping activities decrease. Unfortunately, live trapping and removing the animals to new locations doesn’t reduce or control the population. Calling a spade a spade, it compounds the problem. Immediately after being released into a new neighborhood, the industrious amphibians begin constructing dams that will flood roads, trails, nests containing eggs of game birds and waterfowl, not to mention spawning habitats important to Maine’s trout and salmon fisheries.

Typical of most wildlife species, beavers are prolific. Females normally breed at age two and produce annual litters averaging four “kits,” occasionally six or eight. A colony of beavers may consist of 10 or more animals.

Like anti-hunters and animal-rights advocates, anti-trapping activists apparently think wildlife would cease to proliferate if trapping were prohibited. The burgeoning beaver population clearly indicates otherwise and documents the importance of controlled trapping to fisheries and wildlife management.