It’s a fever.. of xenophobia:

An army of foreign mammals, birds and amphibians is poised to invade Britain – changing the countryside and threatening our best-loved native wildlife, scientists warn.

They have identified 84 exotic species – from the raccoon to the snapping turtle – which could become established within the next few decades.

Some, like the leopard cat, could escape from zoos or private collections, while others, such as the eagle owl, are already living in isolated pockets of the countryside.

from the “Raccoons and Snapping Turtle Join  the Foreign Threat to our Native Wildlife,” Daily Mail, May 2009

the operative word is could…