I’ve found my way to the end of the world, or more precisely Ushuaia on the southern tip of Tierra del Fuego. I’m most interested in seeing some of its most recent immigrants, the Canadian beavers (Castor canadensis). Beavers were introduced to the island in 1946 to try and establish a fur trade, the same misguided intent which led to the introduction of Australian possums to New Zealand. As the island invasion story always goes, with no native predators and vulnerable ecosystems, the beavers had the complete run of the island, and have literally begun terraforming it with their network of beaver dams. The landscape is hauntingly like New Zealand, which is not a surprise given the Gondwanan connection via Antarctica, which only makes the beaver logging all the more striking to me.
I arrive in Ushuaia and decide my best bet to find beaver is to go hiking in the Tierra del Fuego national park just west of town. With ample tracks I am assured beavers, or at least their sign, are easy to find. A man dressed as a giant penguin walks past me on the street screaming (strangely in English) “follow me beaver”, and then a woman dressed as a giant beaver comes around a corner to follow. I’ll admit to being quite confused by this, what do beavers have to do with penguins, surely they do not belong together? The link is the tourism, despite their completely different roles in this ecosystem, both are cultural icons for the region. I wander in to piratour and ask about each of their penguin and beaver tours. The penguin tour is a clear winner, up to three species of penguin (Magellanic, Gentoo and King) nesting on a small island in their native habitat, versus wandering around some ponds looking for an invasive species.A substantial beaver dam shows the extent of ecosystem engineering in Tierra del Fuego national park (Photo by James Russell).
Despite their keystone cultural role; both a threat and an opportunity for tourism on the island, plans are afoot for potentially eradicating this most charismatic of rodents from Tierra del Fuego. It is estimated the beavers inhabit an area of about 60,000 hectares, necessarily restricted to waterways. There is urgency to this eradication plan, as some bold beavers are starting to swim the Magellan Strait across to Patagonia where they are now establishing. In Italy the early invasion of North American grey squirrels (Sciurus carolinensis) was not eradicated, and now they are spreading across continental Europe. But beavers are by no means the only introduced mammal on Tierra del Fuego, there is also mink, muskrat, foxes, rabbits, and more…
As I hike up the cerrano guanaco in the national park I spot from my vantage point on its slope an active beaver dam. I try to stalk the beaver, but it sees me coming and warily swims away towards the safety of its dam. I break in to a sprint and the beaver only further mocks me by diving below. As I wait patiently for it to re-emerge, a family of upland geese (Chloephaga picta) take issue with my presence around the pond they share with the beaver, and I decide the beaver has won this round. Ultimately, as it turns out, the closest I get to beaver is eating it that evening at Volver restaurant on the waterfront, where it turns out beaver salami goes perfectly with capers and cheese.