The University of Georgia helps battle a Patagonian beaver invasion
Cox News Service
Sunday, Nov. 18, 2007

By ANDREW MARRA
Cox News Service

BUENOS AIRES, Argentina — In American culture the beaver is as benign a rodent as ever was —- an amiable, blue-collar vegetarian with a penchant for erecting public works and a protagonist of children’s television shows.

But in southern Chile, it’s wanted dead or alive.

About 60 years after 50 were introduced into South America’s sub-Antarctic Patagonia region in a doomed effort to install a fur trade, the beaver population has exploded.

Today more than 50,000 roam freely in southern Patagonia, a region shared by Chile and Argentina, gnawing their way with abandon through virgin forests unaccustomed to tree-eating predators.

Chilean conservation officials are sounding the alarm as the beaver population spreads north, leaving miles of dead forest in its wake. The government is paying trappers by the pelt and has gone as far as to encourage Patagonian restaurants to serve the foreign rodent on their menu.

They are also starting to consider more drastic measures, like widespread poisoning in some areas, to eradicate the beaver entirely.

The ramped-up efforts at the south end of the world are being driven in part by research by the University of Georgia, which recently published the first-ever study documenting the animal’s damaging effects on Chilean river wildlife.

The study’s findings have deepened concerns about the beaver’s threat and given more fuel to those who want its tail on a platter.

“The reason people are concerned is the landscape change,” said Chris Anderson, a former UGA doctoral student who spearheaded the university’s research efforts in Chile. “If the beaver gets established on the mainland, there’s nothing to stop it from going all the way to Santiago [the capital].”

The North American beaver has been thriving for decades on a series of islands on the southern tip of South America, a spectacular region of forests and ancient glaciers considered one of the world’s most pristine natural areas.

The problem is that the Southern Beech trees that dominate Patagonian forests in that region did not evolve the same tactics that many North American trees did to survive alongside beavers, such as bad-tasting wood or an ability to regrow from the trunk.

The result is that “it’s just a big vacation for the beavers,” said Anderson. “The beaver eats them all.”

The beaver is not the only invasive mammal creating problems in southern Chile. Foreign species like mink and rabbits are also wreaking havoc, preying on bird eggs and native plants.

But it is the beaver that has had the most dramatic effect on the landscape. As it mows down trees to build its dams and beaver ponds, it leaves large swaths of dead forest behind it.

Anderson said it is no understatement to call it “the largest thing that’s happened here [ecologically] since the melting of the glaciers 10,000 years ago.”

Conservationists are especially concerned given the region’s iconic natural splendor. Its ruggedness is what attracts droves of tourists to the area and earns Patagonia its reputation for untouched beauty.

“People don’t come to the end of the world to see dead forest,” Anderson said.

The Chilean government started its first trapping program in 2003. This year, the project has been renewed and will likely be expanded to include other tactics besides trapping, possibly including poison, Anderson said.

Anderson, through his research for UGA and subsequent work, has become one of Chile’s leading authorities on the beaver’s effects.

While pursuing his doctorate in ecology at UGA, Anderson spent five years splitting his time between the Athens campus and Puerto Williams, Chile.

After graduating in 2006 he resumed his work there —- both as a fellow for the Millennium Institute of Ecology and Biodiversity and as a researcher at the Omora Ethnobotanical Park. He now also sits on regional and national invasive species advisory boards in Chile.

Nicolas Soto, who heads the national Department of Agriculture and Livestock’s harmful species control program in southern Chile, praised Anderson for the vital role of his research and his “constant efforts to build bridges between science and management.”

Anderson’s involvement at Omora has also led to the creation of a formal relationship between the research organization and UGA. The university has sent a half-dozen other students there to do related research on invasive species, such as the mink, and received a Chilean student who came to Athens to study international law.

“He’s been uniquely successful,” said Amy Rosemond, an ecology professor at UGA who supervised Anderson’s doctoral research. “It’s relatively rare that students are positioned in places where they can get their research translated into management policies.”

Andrew Marra is a Buenos Aires-based freelance writer on assignment for Cox Newspapers