Louise Gray, The Telegraph 21 May 09;
Invasive species such as the grey squirrel, American mink and Muntjack deer are already causing havoc in many areas of the country.
Now Natural England fear a whole new generation of foreign species could take over in Britain. In a new report 84 out of 161 animal species were identified as posing a risk.
Animals that are already in the country include the agressive snapping turtle from North America that will take young wild fowl, the Egyptian goose that is known to usurp the nests of barn owls and the African clawed toad that threatens endangered native amphibians.
The scientists also identified animals that are already circulating as pets or could be transported accidentally through foreign imports that would pose a "high risk" to British wildlife if they are released. The list includes leopard cats, racoons, American beaver, Arctic fox, marbled crayfish and Asian longhorn beetle
Poul Christensen, Acting Chair for Natural England, blamed ease of travel that means aninmals are being spread through imported plants, by tourists and even on the bottom of boats.
"It is no exaggeration to say that our native wildlife is increasingly exposed to its own form of globalisation as non-native species increasingly gain a foothold," he said.
Mr Christensen said the report highlighted species like the red-eared terrapin and eagle owl, that are already causing a problems as well as more exotic species like the Arctic fox and American beaver that are controlled at the moment but could pose a risk in the future.
"Non-native invasive species compete for food and habitat and sometimes carry viruses which our native wildlife often cannot fight off - the fate of our red squirrels, water voles and native bluebells is evidence of how dramatic the effects can be," he said.
"The report highlights that new arrivals and the steady expansion of current populations of non-native species could have significant impacts on native wildlife and their habitats, disrupting the normal functioning of the natural environment. The key will be to anticipate where the main changes are likely to occur so that we can take targeted action to reduce their impacts."
Some of the species identified by the Natural England report as posing a threat to British wildlife include:
Snapping turtles - Originally from the south east of the United States of America, it was released by pet owners and has been blamed for taking fish and young waterfowl.
African clawed toad - Feeds mainly on fresh water crustaceans but it is feared it will also take tadpoles of native species.
Leopard cat - Currenly kept as a pet or in animal parks in the UK. If the small cat from Asia was released it would threaten native birds and mammals.
Raccoons - The animals from North America are kept as pets but could become as problematic as the grey squirrel for trees and the native red squirrel if allowed to spread in the wild.
Asian longhorn beetle - The insect from China has already caused problems for trees in the US and could be accidentally imported into the UK on popular garden plants.