North American beavers have wiped out 30 percent of forests along rivers and streams in Tierra del Fuego, at the southern tip of South America, causing the greatest landscape change to these fragile forests in the last 10,000 years. The governments of Chile and Argentina want the invasive beavers gone, but eradicating them has proven to be difficult, a research team found, because it requires the participation of every single landowner in the area. “Payment programs help, but getting all landowners on board is the crux of this and many other invasive species eradication programs around the world,” Assistant Professor Michael Sorice, a co-author, said.

The team’s research, published in Global Environmental Change, shows that landowners were willing to participate in a beaver removal program. “Landowners preferred a program that would allow the program managers to have access and complete control over beaver eradication on private land,” said forestry master’s student Anna Santo, lead author. The study’s unexpected finding that landowners prefer a program that takes more control over beaver eradication on their land may be a result of economic setbacks (such as the decreased demand for Patagonian timber), tax increases, depredation of livestock by wild dogs, and a shortage of skilled ranch labor.

In 1946, the Argentine government introduced 20 North American beaver to create a fur industry; the mammals have expanded into Chile and now number over 100,000. The two nations have signed a binational treaty to eradicate the species before its ecological impacts spread further, to the mainland and throughout the archipelago.