Canadian beavers are chewing their way through the forests of South America and leaving an irreparable swath of destruction in their wake.

Sometimes an idea that looks really good on paper can turn into a disaster in real life. In the case of a 1946 plan that introduced approximately 25 pairs of Canadian beavers to Chile and Argentina’s shared archipelago of Tierra del Fuego, it’s become a full-fledged disaster of the natural variety.

At the time of their introduction, it was thought these big-toothed rodents could help kick-start a fur industry in South America. Canadian pilot David Lamb was tasked with trapping and flying the animals to Tierra del Fuego, although he claims he managed to only capture 20 of the animals, not the full 50 requested by the Argentine government. Regardless the exact number back then, this much is certain today: that initial double-digit group of beavers has ballooned to over 200,000.

Hindsight allows us to now sit back and ask the question, “What were they thinking?” when the details of this cross-country beaver immigration are studied. North American beavers weigh, on average, 60 pounds (27 kilograms). They need water (ponds, rivers, etc.) on which to build their lodges. They also need a lot of trees and foliage from which to build those lodges and form those ponds, which is where their penchant for dam engineering and construction comes in. They do not hibernate, which means they are chopping down trees year-round to feed on. Plus their teeth never stop growing, so every instinct in their pudgy bodies is telling them to chew whatever they can to keep their chompers from getting too long for their mouth.

So yes-trees are a big thing for beavers. But when you introduce an animal which leaves a significant environmental footprint into a region that has no natural predators to keep that animal’s population numbers in check, bad things happen very quickly. When your original concept of trapping the animal for their fur becomes a bust because it turns out your native hunting industry can’t figure out how to actually accomplish that job, and you end up with 200,000 of the planet’s biggest rodents chewing their way inland and wiping out everything natural in their path.

Currently steps are being taken to cut these Canadian beaver numbers in half over a ten-year time period through hunting and trapping. Some officials have suggested the trapped beavers be sent back to Canada, but the odds are extremely slim of that ever happening. It might seem like it’s a cruel fate for an animal that never asked to be where it is, but the extermination plan has the backing of both the United Nations and environmental groups.

Story by Jay Moon