Beavers in Tierra del Fuego cause massive ecological damage

An invasive population of North American beavers (Castor canadensis) in Tierra del Fuego is causing significant ecological and economic damage. Originally introduced in 1946 with just 20 specimens to establish a fur industry, the population has exploded to over 100,000 individuals due to a lack of natural predators.

A study led by Alejandro Huertas Herrera from the Centro Austral de Investigaciones Científicas (CADIC-CONICET), published in the journal PLOS ONE, utilized satellite imagery to quantify the impact. The research identified 206,203 beaver dams across the archipelago—100,951 in Argentina and 105,252 in Chile—a figure that triples previous estimates.

The beavers have colonized approximately 95% of the region's watersheds. Their dam-building activity transforms rivers into lagoons and destroys native Nothofagus forests, which are not adapted to the flooding and tree loss caused by the rodents.