Invasive North American beaver (Castor canadensis) habitat selection and impact in Tierra del Fuego, Argentina

JONATHAN J. HENN; CHRISTOPHER B. ANDERSON; GUILLERMO MARTINEZ PASTUR

Salt Lake City

Congreso; XXIV IUFRO World Congress; 2014

International Union of Forest Research Organizations

Since their introduction in 1946, North American beavers (Castor canadensis) have spread through all of Tierra del Fuego, fl ooding and felling trees in riparian zones. As beaver populations have grown and spread, the governments of Argentina and Chile decided to eradicate beavers and restore degraded areas. However, little work has been done to understand beaver habitat selection and the areas that beavers could potentially occupy in the near future. The goal of this study was to fi ll this gap by surveying satellite images for beaver impact through the whole Argentine side of Tierra del Fuego. To do this, a grid of 175 points of approximately 200 ha each were surveyed for number of beaver ponds and area affected by beaver. Overall, there was an average of 1.7 beaver dams per 100 ha, and beaver engineering affected an estimated 1.4% of the total land area. Beaver effects were present more often than expected in forested areas (X2=42.35, df=5, p