[MeadowMouse]

Interesting to see the debate on introduced North American Species in the UK. It has happened in reverse though. Our Small White Butterfly got introduced into the US and is now driving out the native Mustard White. An interesting point is that the Mustard White is the same species as out Green-veined White which happily co-exists with the Small White in the UK and the rest of Europe yet in North America the two species cannot co-exist.