January 15, 2012

Bloody foreigners

An interesting piece from The Guardian here, about invasive non-native species that are threatening some of our British plants and animals. The usual suspects are all present and correct: harlequin ladybirds, grey squirrels, signal crayfish, water primrose. And it's hard not to worry in the face of such gloomy predictions for the UK's unique habitats and local ecosystems.

Yet plants and animals have moved around the globe for millenia, particularly in mainstream Europe, and have naturalised perfectly well in their adopted countries: neither rabbits, nor apples, nor horse chestnuts are truly local to the UK, after all, but we treat them as 'honorary natives'. So isn't there the merest whiff of jingoism about our current horror of being... invaded?

My guide, as in many ecological issues, is Richard Mabey, whose breadth of knowledge and astuteness of understanding take some beating. "The fact is, there is no absolutely clear line between native and introduced species, or between their effects," he says. "Most exotics aren't especially pushy, and prosper only if they find a vacant niche – as did, for instance, the little owl (introduced from the Continent in the 1870s) and the collared dove (arrived under its own steam from south-east Europe in the 1950s)."

He goes on: "What is disturbing is an ideological opposition to introductions simply because they are foreign; and a conviction that conserving biodiversity means fossilising species, turning habitats into isolation wards, ecological theme parks. Biological diversity evolved by exactly the opposite process, by species mutating, developing, cross-breeding and radiating out." The fact that we are an island nation should not, I think, lead us to attempt to halt that process in its tracks.

Two recent attempts to curb 'invasive' species spring to mind, neither of which are very edifying. A hedgehog cull in the Western Isles of Scotland provoked outrage: after all, these charming animals have fallen in numbers on the British mainland by nearly 90%. And the ruddy duck, a lovely blue-billed waterfowl, was recently deemed to be interbreeding with the white-headed duck, and within a few months was all but eradicated from British waterways.

Is this approach either ethical, or sustainable? I'm not sure. Perhaps it's worth looking at our own role as 'invasive species', and the damage we as humans do to fragile ecosystems worldwide.