We should welcome rather than fear nature's 'invaders'
Published 12/08/2015 | 02:30
Invasive species such as rhododendron, zebra mussel, Japanese knotweed are evil and we should be making every effort possible to drive them out of country, eh?
Had I been asked that question a week ago I would have uttered an unambiguous YES.
But having since read a recently published book called The New Wild, Why Invasive Species Will be Nature's Salvation, by Fred Pearce, the situation does not seem so clear-cut.
Taking a colourful journey around the world from the Pacific to the Galapagos Islands, from the Australian outback to urban Britain, Pearce doesn't deny that aliens/non-natives/ invasive have an impact but says the nature of this is often more complex than we may think.
We all like a simple story with good guys and bad guys and the widely-held conservationist view on invasive non-native species is, as quoted by Pearce, that they are "the second greatest threat to biodiversity worldwide after habitat destruction".
Pearce questions the basis of this claim and presents various examples of how non-natives have actually added to biodiversity, with more new species arriving than made extinct, and supported native species.
In Hawaii, alien birds such as the Japanese white-eye and red-billed leiothrix, introduced from India a century ago, are today the mainstay for dispersing the seeds of native shrubs.
What I did not realise because I never thought about it is that non-natives often take hold in an area because the natives are struggling. This, in turn, is because the environment has been altered by our behaviour. Rather than being the problem per se they are a symptom of something more fundamental. They may be "passengers more than drivers."