Sbarramento di castori nella Terra del Fuoco (Argentina 2005)

The governments of

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

are attempting to eradicate the

North American beaver The North American beaver (''Castor canadensis'') is one of two extant beaver species, along with the Eurasian beaver (''Castor fiber''). It is native to North America and introduced in South America ( Patagonia) and Europe (primarily Finland ...

in the

Tierra del Fuego Tierra del Fuego (, ; Spanish for "Land of the Fire", rarely also Fireland in English) is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of the main island, Isla G ...

area at the southernmost tip of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. This

non-native species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

was introduced in 1946 as a potential source of commercial

fur trading The fur trade is a worldwide industry dealing in the acquisition and sale of animal fur. Since the establishment of a world fur market in the early modern period, furs of boreal, polar and cold temperate mammalian animals have been the most ...

. When the putative fur trade industry failed, the beavers became problematic and the governments agreed to intervene to wipe them out. A June 2011

NPR National Public Radio (NPR, stylized in all lowercase) is an American privately and state funded nonprofit media organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It differs from other ...

report stated that the beavers have caused millions of dollars in damages. According to ''

Nature Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...

'', this plan is the largest eradication project ever attempted. Beaver dam in Tierra del Fuego

Background and history

In 1946, the Argentinian government

imported An import is the receiving country in an export from the sending country. Importation and exportation are the defining financial transactions of international trade. In international trade, the importation and exportation of goods are limited ...

fifty beavers from

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

, which were to be released in

Cami Lake Fagnano Lake ( es, Lago Fagnano), also called ''Lake Cami'' (), is a lake located on the main island of the Tierra del Fuego archipelago, and shared by Argentina and Chile. The 645 km2 lake runs east–west for about 98 kilometres, of which ...

with the intention of creating a commercial

industry. Though a viable industry ultimately failed to materialize, the introduction of the beavers into the region has had far-reaching consequences. The

s have no

natural predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s in the area. In their native habitats in North America, bears and wolves prey on the beavers and keep the population under control. One observer noted that anyone considering importing beavers should also import bears, those being beavers' natural predators. According to a June 2011

report, 200,000 beavers are living in the area. Another report puts the number in excess of 100,000, and states the level of destruction as akin to having

bulldozer A bulldozer or dozer (also called a crawler) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous track ...

s thrashing through the area.

Tierra del Fuego National Park Tierra del Fuego National Park () is a national park on the Argentine part of the island of Tierra del Fuego, within Tierra del Fuego Province in the ecoregion of Patagonic Forest and Altos Andes, a part of the subantarctic forest. Establis ...

in Argentina is especially threatened, as the beavers are destroying long-protected trees. The animals have spread beyond Tierra del Fuego itself into the Brunswick Peninsula of Chile, and the government fears further penetration into continental South America. The beavers already threaten around sixteen million

hectares The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is ab ...

of indigenous forest. Unlike many trees in North America, trees in South America often do not regenerate when

coppiced Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeate ...

, destroying the forest. As well as felling trees, beavers create

dams A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, ...

that flood certain areas and thus drown other trees and vegetation. Flooding from beaver dams also damages roads and cattle-grazing pastures. Ecologist Christopher Anderson, professor at the

Universidad de Magallanes University of Magallanes (UMAG) is a university in the southern Chilean city of Punta Arenas. It is a public state university and it is part of the Chilean Traditional Universities. The University of Magallanes was established in 1981 during the ...

, has said, "The change in the forested portion of this

biome A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

is the largest landscape-level alteration in the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

— that is, approximately 10,000 years". A 2017 survey among Tierra del Fuego land managers and researchers shows significant support in eradicating beavers and restoring the landscape. The support for eradication is strongest among managers while the support for restoration is stronger among researchers.

Methods

Some park rangers use

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

traps that snap down on the animal's head and instantly kill it. Private individuals receive rewards for

trapping Animal trapping, or simply trapping or gin, is the use of a device to remotely catch an animal. Animals may be trapped for a variety of purposes, including food, the fur trade, hunting, pest control, and wildlife management. History Neolithic ...

beavers, although success has been elusive. Government officials plan to bring in professional trappers who have specialized dogs and use helicopters and boats to move in rolling fronts. The efforts have been subjected to scientific study. Currently, the emphasis in the

is on control, not on eradication.

References

{{reflist, 2

External links

The beaver in Tierra del Fuego, short documentary with subtitles.

Beavers. Patagonia Invaders, documentary feature film
Natural history of Tierra del Fuego Beavers Mammal pest control Introduced species Environment of Chile Environment of Argentina Pest control campaigns Invasive species in South America

Background and history

Methods

See also

References

External links