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Giant Bird-Eating Mice

Gough Island, a British-owned outcrop in the South Atlantic about 2,000 miles off the coast of South America, is one of the most remote places in the world, uninhabited except for the crew of a weather station. It is also a UNESCO World Heritage Site, home to 22 breeding species of rare nesting seabirds, that live in one of the planet's least disturbed ecosystems. However, that could be changing.

As a report in the British Guardian newspaper notes, whalers who first anchored on the island 150 years ago brought some unintended visitors to Gough: stow-away mice. The rodents slipped off the boats and made a new home on the island, and have since multiplied to a population of more than 700,000 on the 25-square-mile outcrop.

The British house mouse has evolved in its unusual surroundings, growing up to three times its normal size and ditching its usual diet of insects and seeds for the carnivorous delights of albatross, petrel and shearwater chicks, which the mice devour alive in their nests. Birdlife International, a worldwide agency of conservation groups, has spoken out about the mice, saying that because they have no predators on the island, they are out of control and could cause the extinction of several rare bird species. They might also be the largest mice in the world.

As a result of the fowl-eating mice, Birdlife International has put the Tristan albatross and the Gough bunting on the list of the world's most critically endangered species, the highest threat level. Possible solutions to the problem include helicopter drops of thousands of tons of rodent poison.

Because the parents of bird chicks have no experience in fending off predators, the mice pose a particularly lethal threat because they gnaw through the nests to get to the plump, down-covered baby birds; studies have suggested that six in 10 Gough chicks — which weigh about 10 kilograms to the 35-gram mice — die in their nests.

The Gough Island situation is also part of a larger problem confronting Britain, which has been criticized for the lapsed ecological standards of its territories around the globe, including islands such as Pitcairn, Tristan de Cunha, and the Falklands. Great Britain is now responsible for 32 of the world's 190 most endangered birds and is facing increasing calls to pledge more financial support for conservation projects far removed from its home territories.