Beavers a gnawing problem

[Lee Borgersen]

Beavers a gnawing problem for lake residents
December 18, 2011 at 11:17 PM
CHRIS YOUNG
The State Journal-Register

Some residents living at Lake Springfield have a gnawing problem.

Beavers have taken up residence under boat docks and damaged or killed trees and shrubs along the shoreline.

A few homeowners have expressed their frustration, and a notice had to be placed in the Springfield Lake Shore Improvement Association Newsletter reminding them not to take matters into their own hands.

Residents must contact City Water, Light and Power, which owns the land, and seek permission to remove nuisance wildlife.

“With 725 leaseholders taking up a third or more of the shoreline, that makes for a lot of boat docks, and the beavers have to build their lodges somewhere,” said association president Tom Hiler.

Mike Castleman knows firsthand.

He lost a large shrub and two mature trees in a matter of days.

The beavers stripped the bark from his trees to a height of about 3 feet off the ground.



A pair of shingle oaks have been stripped of their bark. Photo (shown below) courtesy of Mike Castleman.

“From what I understand, these trees are dead. This guy killed them,” Castleman said. “I got some pruning spray to seal them and chicken wire to protect them, but everyone who sees them says they are going to die.”

The beavers also reduced a 20-foot-high bush in his yard to a bundle of pointed sticks.

“They are storing the limbs under floating docks so they can eat them during the winter,” Castleman said.

Can’t move ’em

Beavers can be voracious eaters.

A study referenced in “Mammals of Illinois” by Donald Hoffmeister found that six captive beavers ate 180 trees — 1 to 3 inches in diameter — in a single month.

That works out to one tree per beaver per day.

“People are telling me they are 60-70 pounds,” Castleman said. “I don’t know if I want to run into anything that is 60-70 pounds and can eat through a tree like that.”

According to “Mammals of Illinois,” beavers can grow to be about 3 feet long and weigh up to 60 pounds.

Hiler said lake residents have been sharing pictures and ideas via email.

“People have remedied the situation in different ways,” he said. “They gird their trees with cyclone fence or wire mesh to deter the beaver.

“Other people have gone to the extent of getting a permit from CWLP to hire a licensed trapper.”

Removing beavers is only a temporary solution, according to “Missouri’s Beaver, a Guide to Management, Nuisance Prevention and Damage Control,” published by the Missouri Department of Conservation.

“Once a colony of beaver establishes its territory in a pond, lake or stream, it is virtually impossible to make it move somewhere else through the use of nonlethal techniques,” the manual says. “It is sometimes possible to enjoy beavers in the area while still preserving property.”

Fencing of trees and shorelines and fortifying boat docks with wire mesh are ways to discourage beavers.

An upside?

Hiler said the presence of wildlife comes with the choice to live along the shores of Lake Springfield.

“There is virtually everything out here,” he said. “And those things do have a tendency to get in your dock, your house or somewhere you don’t want them.

“If you aren’t willing to tolerate birds, deer in your yard, squirrels, raccoons, and now beavers, you should probably live somewhere else.”

Castleman said his neighbors tarred the trunks of their trees in an effort to keep beavers away.

“It’s cool to see beavers around, but we are going to have to do something,” he said. “I think we’re all starting to figure this out.”

Hiler said the presence of varied kinds of animal life should tell residents Lake Springfield is healthy.

“The beavers wouldn’t be here if the lake didn’t have a high water quality,” he said. “Beavers don’t go into polluted water. There is an upside.”

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Preventing beaver damage

Boat docks:

The shorelines of lakes, such as Lake Springfield, often have too gentle a slope or are lined with riprap that prevents beavers from establishing dens.

Changing water levels also make shorelines less attractive.

Due to a lack of options, beavers may instead try to establish a home under boat docks, chewing out an opening in the foam used to keep the dock afloat.

Foam blocks with gaps in between give beavers space to hollow out a chamber.

When the foam is replaced, butt blocks tightly together and protect with galvanized metal wire.

Mesh should not be greater than 4 inches.

Trees:

Beavers sometimes damage trees for reasons other than food.

Because their incisors grow very quickly, they must continue to gnaw to keep them in check. If the teeth grow in an uncontrolled manner, the beaver could starve.

These “gnaw trees” often are near beaver mounds.

Trees can be protected with a welded wire fence with mesh no greater than 4 inches.

Leave space for the tree to grow. Avoid using chicken wire and do not wrap the tree too tightly.

Anchor firmly to the ground so beavers cannot chew on the roots.

Fences along the shoreline can help keep beavers out.

Source: Missouri’s Beaver, a Guide to Management, Nuisance Prevention and Damage Control

***

An amazing comeback

The beaver was virtually eliminated from Illinois by 1850, according to “Mammals of Illinois” by Donald Hoffmeister.

Beavers, which have the distinction of being the largest rodents in Illinois, declined almost as soon as European settlers arrived.

The animals were reintroduced starting in 1929 when a pair was released at the Savanna Army Depot in Carroll County in northwest Illinois.

Eight additional pairs were released in the county during the 1930s.

Other re-stockings followed.

Beavers are now common and found in every county.

In 2010-2011, trappers took an estimated 11,238 beavers in Illinois, according to the 2010-2011 Illinois Trapper Survey conducted by the Illinois Natural History Survey.