Beavers are an invasive species on the island of Tierra del Fuego in Argentina and Chile. Since their arrival in 1946, beavers have increased their numbers from the original 25 pairs to approximately 100,000 individuals. Beavers are responsible for the most drastic landscape alteration in Tierra del Fuego since the last glacial age, affecting the hydrology and composition of the southern beech forest, but perhaps more importantly allowing other exotic species to invade the ecosystem. This project will study the population dynamics and habitat use patterns of beavers on Tierra del Fuego to develop models designed to help managers who are trying to slow the spread of beavers in the region. ($4,000)