Following a blog on reintroductions how about one on reintroductions' evil twin - introductions?
There is a general rule in biology that about one in 10 non-native translocated species becomes established in its new home - and that then one in 10 of those becomes an economic or conservation problem. Non-native species are one of the prime causes of species' extinction and so carting species around the globe is generally a bad thing (please note - Richard Branson).
Many of the non-native species in the UK were allegedly brought here by the Romans (eg pheasant, rabbit) but others were deliberately or accidentally released by the landed gentry (eg little owl, grey squirrel, muntjac deer and Canada goose). But then there is a long list of species whose origins are unknown but which are here as a result of careless trade across the globe.
This blog has commented on ring-necked parakeets (here, here, here and here), pheasants (here), muntjac deer (here) and grey squirrels (here, here and here) at various times to illustrate the practical and intellectual issues surrounding this subject.
It seems likely that we will face continuing and growing problems with non-native species becoming established in the UK. One of the latest arrivals is the scary creature the killer shrimp. What havoc might this species cause in our waterways? What happened to the New Zealand flatworm that was going to take over our gardens about 15 years ago?
Prevention is better than cure, and far cheaper, but difficult to police and ensure. I just have a feeling that this is a growing problem that we will all have to live with. It won't kill us - but it might finish off a few more native species if we aren't careful. And experience shows, we won't be careful enough.
It is said that the Zulus started a war by drawing the Assegai out of the ground? I suggest draw a line in the sand and should not introduce any more species that do not currently live here and should be ultra vigilant to stop insects and other less visible intruders gaining a foothold.
I also suggest that those other non-natives that are the focus of argument now should be judged on the damage they do or do not do - eg grey squirrels damage trees and carry a pox which kills red squirrels - thus they should be controlled; mink kill water voles - thus they should be controlled and so on.
The fact is that a long time ago man's fingerprints were laid on our lands and it is our responsiblity to manage, having once interferred.
The option to let nature create the balance is foolhardy at best.
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