I wrote about the Church Bird of Borneo a few weeks ago, and asked the question how species could be evolutionary winners and conservation disasters at the same time.
The issue is about exotic and invasive species that are ecologically much better adapted to their new environments than indigenous species, which are often fine-tuned with their native, undisturbed habitats. Disturbance of these native habitats makes the locals suffer, while the newcomers thrive.
Whether they are tree sparrows, Burmese pythons, water hyacinths or humans, all these newcomers are very good at coping with new environments, often at the expense of whoever lived there first. But strangely enough, that is exactly how evolution works. The ancestral Darwin’s Finches once landed, completely exhausted, on one of the Galapagos Islands. They thrived, adapted, evolved and probably displaced quite a few of the species that had arrived before them.
Here in Southeast Asia, I see the same. Every few hundred thousand years, a wave of new species has arrived in the lands that now make up Indonesia and Malaysia, often driven by climatic change. They displaced the original species, which either died out or survived on mountain tops, offshore islands or other unusual places, where they are now rare endemics.
In conservation we are trying to change this. We are eradicating or controlling the invaders, and protect the natives. But that introduces a paradox.
Of course, things are happening much faster now that humans have come onto the scene. We are not talking about millennia or even centuries anymore. Our changes happen in a few years. And few species can adapt to that speed.
Still, there seem to be a disconnect between conservation and natural evolution. Come to Borneo in a few thousand years from now, and quite likely the tree sparrows here will have started to develop some useful traits that allows them to exploit new resources.
When does a species stop being a dangerous invasive and become a wonder of nature worth protecting?
(Image: Sketch of four finches by John Gould that were discovered on the Galapagos Islands by Charles Darwin, from the 1845 edition of Darwin’s Voyage of the Beagle. Credit: John Gould via a Creative Commons license.)