Patagonia Week - Patagonia's problem with North American beavers

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Isn’t it amazing that we have been able to contribute to the extinction of so many species, yet we can’t seem to eradicate the ones we want to.” – a sailor’s snippet on conservation in Patagonia.

Like any good non-native species story, this one starts with an idea. This particular idea came to light in the 1940s, when the Argentine government introduced 25 pairs of North American beavers (Castor canadensis) to the Tierra del Fuego archipelago to begin a fur industry.

Despite being exploited the beavers thought this idea was a splendid one. With no native predators and forests aplenty the population swelled to an estimated 100,000 individuals in the early 2000s. Sadly, Argentinian and Chilean beech forests did not come off well during this period. North American beavers have the illustrious title of being an ecosystem engineer, and they quickly began to alter the morphology and hydrology of the area by felling trees and damming the numerous waterways. While the North American forests had co-evolved with the beavers habits, the south American forests did not have the ability to regenerate and the beavers soon became an unwelcome guest.

Initially efforts were made to control the swollen population, but in 2008 ‘war’ was declared on the beaver, and an international team embarked on the largest eradication programme ever attempted. The aim was to both prevent the beaver moving further north through the continent, and remove those that had already established.

As yet the jury is out as to whether the project is successful, however the evidence of the beavers throughout Tierra del Fuego is not difficult to find, In fact it’s more difficult to find a waterway that does not have evidence of beavers. The dams, large lodges and numerous felled trees indicate that the beaver has well and truly planted the flag to stake a claim over 7 million hectares of prime Patagonian real estate.

And, it’s due to their successful colonisation that we ended up having dinner with a North American beaver on the southernmost tip of Argentina: