That sounds very authoritative but in fact is baloney. Introduced crayfish are swamping and destroying our native stock due to :
the strongest survive and the weakest fall
QUOTE]
Bearing in mind that the American and Italian crayfish was brought into Britain by man, this cannot be a case of natural selection. (with the invasive crayfish also carrying a disease)
There always appears to be a time frame involved with such matters, but usually anything that has been in a given geographic region for less than 200 years would be considered undesirable and in fact almost always does have a detrimental, if not catastrophic, effect on native species.
depending on the point of reference, the european eagle owl is believed to have been living in Britain since before the ice age and almost hunted to extinction in the UK.
Even though there is a release program, this bird has never been recognised as a 'British' Bird so therefore is not protected as our truely native birds are.
... incidentally, Harry Potter caused a huge amount of damage to Owls
Beavers were extinct in the UK in the 16th century but are being reintroduced as have Elk (extinct in the UK 5000 years ago).
Lynx extinct in the 10th century, Wolves in the 17th century and even bears have been considered!)
Wild Boar are now wild again (extinct in the UK 500 years ago)
playing god springs to mind
