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All images and text © Kevin Moloney


With a naturally small variety of wildlife, Tierra del Fuego is overrun with exotic species, the most notorious of which is the Canadian beaver. Nearly twice as many introduced species of mammals inhabit the region as natives — including the dogs, cats, rats, mice, horses, cows and sheep that come along with human settlement. Among all of those, too, there are wild examples roaming the hills and forests of the islands. For the 10 native mammal species, there are 19 invaders competing in their environment.



The beaver was introduced to Tierra del Fuego along with the muskrat in 1946 in hopes of spurring a fur industry. Free of the bears and wolves that check their numbers in North America, the original 50 Canadian beavers have exploded to an estimated 30,000 to 50,000 on the Argentine half of the main island of Tierra del Fuego. Tens of thousands more cruise the waterways of the Chilean side.



By flooding river channels, washing out roads and cutting forested land, the beaver is the most visually damaging of Tierra del Fuego's invaders. They certainly catch the greatest institutional attention. The beavers, says researcher Julio Escobar, "have a visual impact that the politicians can see."



In an act that will earn a death penalty from park rangers, a beaver builds a quick dam in a culvert along Tierra del Fuego National Park's main road. Fencing, like that seen above, has reduced damage to the park road by beavers, but the crafty engineers will still seize any easy opportunity to create a pond for their dens. By blocking road culverts or flooding nearby waterways, beavers inundate many of the island's back roads.



Though a natural part of the North American ecosystem, the busy rodents have eagerly inhabited 90 percent of the island's river systems, causing probably permanent damage to trout spawning creeks, river drainages, water quality and the habitats along the edge of Tierra del Fuego's once-clear mountain streams.


All images and text © Kevin Moloney

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