Beavers

endanger

tree project

Trapper called in

By CHRIS VETTER

Journal Staff Writer

NEW ULM -- Michelle Rorer of Minneapolis was in New Ulm working on her University of Minnesota water science research project recently when she noticed a disturbing problem.

Trees were vanishing. A lot of trees -- near the New Ulm Waste Water treatment facility near the Minnesota River.

The culprit? Beavers. Two or three colonies, numbering 35-40 overall, have been tearing down experimental trees on the 30-acre plot for food and making dams.

Rorer sought and received permission from the New Ulm City Council to hire a trapper to eradicate the destructive beavers.

"It's a matter of urgency," Rorer said.

Rorer has been making trips to New Ulm every other week throughout the year. She first noticed the genetically-altered poplar trees -- a hybrid of aspen and cottonwood -- vanishing in early October. Six weeks later, nearly 400 trees have been chopped down, leaving only short stumps.

The growing beaver population poses a problem, according to Don Schultz, area wildlife manager for the Department of Natural Resources out of Redwood Falls.

"Beavers are great in a natural world. They can make their own ponds and positively affect other wildlife," Schultz said. "Unfortunately, when you start backing up water, it causes problems for humans, causing agriculture drainage problems and crop depredation."

The beaver population is high largely because beaver fur is not selling well, Schultz explained. Thus, fewer trappers are actively hunting beaver.

Complaints of beavers backing up culverts are rising in the area, according to John Erb of the Madelia DNR office.

"We're seeing more and more beaver just show up, in habitats we wouldn't expect," Erb said. "This is the first time I'm aware of (beaver) in the city of New Ulm."

Francis Rieger, who works at R&R Bait and Tackle in New Ulm, has been hired by Rorer to eradicate the beaver population.

"There are a lot of beaver down there," Rieger said. "Something's got to be done, or (Rorer's) whole program is gone."

And beavers love the poplar trees, he said.

"It's like eating lettuce out there," Rieger said. "It's their favorite meal."

Beavers tend to move around a lot, and Rieger said he is not surprised that the trees just began to vanish.

"Now is when they make their big stash for winter food," Rieger said.

Rieger began trapping the beavers Saturday. He quickly racked up seven beaver kills, including one beaver that weighed in at a hefty 65 pounds.

Erb is not surprised by the size of the beaver because the animals can reach 75-80 pounds. An average beaver at this time of the year weighs 40 pounds.

"Until you see one up close, people don't realize how big they can get," Erb said.

This year, beaver trapping season opened Nov. 1 and continues until May 15. However, a person needs a permit to trap beaver in New Ulm, Erb explained. The City Council granted that permission at its last meeting.

Schultz estimates there are 8,000 beaver trappers in the state.

"Chances are a trapper will go hard at a colony, and be done within two weeks," Schultz said.

Rieger said he will trap beaver for another two weeks, until the Minnesota River freezes. Once that occurs, beaver usually stay inside the dam for much of the winter, eating the food they've already collected.

There are two common types of traps used to kill beaver, both placed in the water. A leg hold grabs a beaver and pulls it quickly under water, where the animal drowns in under three minutes, Erb said.

"Studies have shown it's a pretty humane way to kill a beaver," he said.

The other trap is called a 'conibear.' When a beaver swims over the conibear trap, it swings shut, killing the beaver within 30 seconds, Erb said. The conibear could snap a beaver's neck or restrict its breathing.

"It usually results in a pretty rapid death," Erb said.

Beavers are protective of their habitat, and they will fight beaver from other colonies, but are generally afraid of humans, Erb said.

"They're not going to try and hurt someone unless they are cornered," he said. "They're a docile animal."

Erb said there are a number of reasons to not use 'live traps' to catch and release beaver. He said there is not a great deal of open space to free the animal. Also, he believes it would not be humane to place the beaver in an unfamiliar habitat at winter time.

"Live traps are very expensive, costing $300 or $400 a piece," Erb added.

Rorer said she feels bad about the beaver extermination. She has been studying the hybrid poplar trees, which were planted by Rahr Malting in 1998 as part of an agreement that allowed the company to expand its Shakopee facility.

The genetically-altered trees grow extremely fast, and might be used as 'biofuel' in the future, Rorer explained.

Rorer, a graduate research assistant in the University's College of Natural Resources, began the project in summer 1999. She uses a device to capture water as it passes through soil along the Minnesota River bank and measures the nutrient content that remains in the soil. Her goal is to find that the soil is retaining the nutrients from the poplar trees.

Rahr Malting should have considered the fact that beavers like to eat these poplar trees before planting began, Rieger said. He suggested that snowfence should have been placed around the tree area to keep the animals at bay.