They are close encounters of a deadly kind. A seven-year project to restore extinct and endangered animals and plants in Britain is under attack from alien species. English Nature is spending 750,000 pounds sterling to help restore the populations of endangered species indigenous to the British Isles such as the water vole, the dormouse and rare fish. Its efforts, however, are being hampered by voracious foreign invaders such as the mink, the North American bullfrog and Chinese crabs. "Historically, there have been waves of invaders and we have had to tackle them," said Dr Roger Mitchell, species co-ordinator for English Nature. "There are several types of imported deer which can cause problems, as well as other animals like the grey squirrel and the mink." The species recovery programme has identified more than 200 rare breeds. The population decline has been halted in only about a quarter of the listed rare species, but workers have found alien species regularly threaten to sabotage their conservation mission.... River and pond life is also under threat from imported creatures. The Chinese mitten crab, first recorded in European waters in 1912, is now well established on the Thames threatening rare native species, such as white-clawed crayfish. North American bullfrogs have been blamed for devouring rare pond life, while imported newts threaten the long-term existence of rarer amphibians such as great-crested newts because of cross-breeding. "Predators imported from other countries and then released into the wild can cause havoc," said Jim Foster, of the conservation group Frog Life.
"North American bullfrogs will munch their way through other amphibian life and will even eat fish and small birds. Importing them is now banned." Few British exports have been successful in terrorising the wildlife of countries that we once ruled. One is the wild rabbit, introduced into Australia in 1859, which is now one of the country's foremost environmentalpests, blamed for killing off the greater bilby and the burrowing bettong. |
