Beavers moving into federal reservoir are a sight for tourists, but require some damage control.

Neal Whitaker is happy for the thrill visitors to Marion Reservoir in Kansas getwhen they see beavers swimming or at work along the coves of the lake.
This area, along with most of North America except for the Southwest and
Mexico, has become beaver country. It’s another success story of an
animal nearly extinct coming back over the last 40 years.
But Whitaker, as reservoir park ranger, is equally aware that the
industrious nature of the beaver, true to its reputation, can cause
problems and more work for the people at the lake.
Once the beavers even built one of their lodges in the boathouse at
Cottonwood Point, he said.
Another time, in the same area, beavers plugged a corrugated metal
culvert full of sticks under a low-lying road to create a flood area.
The large aquatic rodents with waterproof, rich, glossy, brown fur,
black webbed feet and a big flat tail have a hearty appetite for trees.
Beavers use their continuously growing front teeth to harvest and eat
bark and cambium, the soft growing tissue under the bark of trees, said
Rebecca Anderson, researcher for the University of Michigan.
Beavers can close their noses and ears while swimming under water, and
they have a clear eyelid to protect their eyes.
Asked about a visitor from Colorado who went up Durham Cove to Broken
Bridge by canoe at night, and heard thrashing and slapping in the water,
Whitaker said that could have been beavers with their characteristic
tail slap to warn of danger.
The wood is also used by beavers for construction material in lodges,
dams and nesting.
Whitaker said favorite trees of beavers in Kansas are willows,
cottonwoods and sycamores, including the large shade trees in reservoir
parks. The beavers have microorganisms in their cecum, a sac between the
large and small intestines, to digest wood cellulose, water vegetation,
buds and roots.
Although there is no official population count on beavers, Whitaker
said: “We have a large population living at the lake. Just about every
cove has beaver runs.”
Beaver runs are the mud paths and slides into the water.
He added that the populations most likely extend up the creeks that feed
into the coves wherever water depths are suitable.
“They create problems for us in the camping parks damaging and killing
trees,” he said. “We do limited trapping in parks, Cottonwood Point,
Hillsboro Cove, Marion Cove and French Creek, usually taking six to a
dozen of them a year.
“Outside the parks, we don’t necessarily bother them. They’re free like the other wildlife. People enjoy seeing them, especially the kids.
There’s a lot of them in the wildlife areas.”
Whitaker said it’s more difficult to find people to trap problem beavers
now because of the depressed fur market. Their population bounces back,
in part, because they’re good family animals.
Anderson said beavers are monogamous. Females mature at 2 1/2 years old
and give birth in the spring after three months gestation, to four to
eight kits.
The babies, ready to go at birth with eyes open and incisor teeth
erupted, stay up to two years in colonies of as many as eight
individuals with older siblings helping with the young.
Beavers are mostly nocturnal, and some Marion County residents report
shooting them with a rifle in moonlight as an alternative to trapping
for damage control. Farmers have reported outer rows of crops taken like
trees along stream banks.
It is true that beaver meat can be eaten. Whitaker has eaten beaver
barbecued, but the sauce disguised it.
“I can’t say if it tasted good,” he said. “They have a pretty clean
diet, so I wouldn’t be afraid to eat it.”
Whitaker and Anderson both said people are more likely to see beaver
lodges in the faster-flowing areas of rivers and streams where the
beavers need lodges and dams to slow the flow, and stabilize the living
area.
At the reservoir, Whitaker said, beavers usually burrow back under the
bank with caches of branches for food kept under water.
“There’s also been a couple of lodges, one pretty good sized one north
of Cottonwood Point several years ago,” he said. “The placement of
tunnels and lodges varies with the water level.
“It seems to me they like to have a steep bank that goes quickly into
deep water to get the wood in the water quickly, just like people like
it for boat ramps and where most of the parks are. They’re not nearly
the problem in parks where the water’s shallow. That’s just kind of a
personal observation.”
On the positive side, beavers are noted for creating water habitats for
many species, helping keep the water table up, and controlling flooding
and erosion.
Gerald Wiens, Marion wildlife photographer and biologist, said in his
travels he hasn’t noticed any rapid increases in beaver population, just
the slow return of the animal over the last 30 to 40 years.