European butterflies could face dramatic extinctions should global temperatures continue to rise, a new study says.
If the colorful insects try to migrate north to cooler climes, habitat destruction—such as deforestation—and large bodies of water might stop them.
"The problem for the butterflies is that the steps they have to take [to migrate] could be rather big ones," explained Josef Settele, the study's lead author and an ecologist at the Helmholtz Centre for Environmental Research in Germany.
"They might have to bridge gaps of 30 to 40 kilometers [18 to 15 miles] in one generation, and that becomes big," he added.
If small numbers of a butterfly species do survive a northern migration, they still may not thrive. The insects may not be able to reproduce in sufficient numbers or their new habitat could degrade.
Meanwhile, even a few degrees of warming could kill most butterflies that don't migrate, the authors say.
In the past few years, scientists have predicted that plants—and the animals that depend on them—will shift to northern latitudes and higher elevations as global warming pushes them out of their native habitats.
The prevailing belief is that species that can't migrate quickly enough won't survive.
(Related: "Extinctions Could Have Domino Effect, Study Says" [September 9, 2004].)
But some researchers are cautioning against what they consider a simplistic and pessimistic viewpoint. Even Settele acknowledges that "we should not neglect the potential of nature to adapt to changes."
"Some insects are able to evolve quite rapidly—there is also some hope there," he said.
The new report appears in a recent issue of the online journal Biorisk.
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