Thousands of mammal species living in 20 regions could extinct in coming years as the human population grows, scientists reported on Monday.
In a study published in the March 6 issue of The Proceedings of National Academy of Science, researchers said they have identified 20 potential extinction "hotspots" for mammals, places where animal species could decline rapidly under the influence of possible human activity.
The animals have a "latent" risk of extinction, that is, they are currently less threatened than their biology would suggest, usually because they inhabit regions or habitats still comparatively unmodified by human activity. More than 1,500 mammals might face the risk of extinction, researchers warned.
Among the species with the highest latent extinction risk, according to the new study, are the North American reindeer, the musk ox, the Seychelles flying fox, and the brown lemur.
Of the 20 identified areas, two regions with high potential risks are the forests and tundra of northern Canada and Alaska, and the vast island chain from Indonesia to the South Pacific. Other hotspots include the Bahamas, Tasmania, and the Patagonian coast.
Latent risk is particularly low in many parts of the world already modified by human activity, such as Europe, Japan and New Zealand. Human impact has already been felt in these areas, meaning that there are comparatively few surviving species with high latent risk, the researchers said.
These hotspots combine relatively low human impact with a mammal fauna made up of species which are inherently sensitive to disturbance.
Since many of these latent areas are still relatively undisturbed, according to the study, cost-effective, preemptive conservation measures may help prevent future species loss.
Conservationists should act now to protect mammals such as North American reindeer which risk extinction in the future, the researchers noted.
"We hope conservationists will use our findings to preempt future species losses, rather than concentrating solely on those species already under threat," said Marcel Cardillo, leading author of the study at the Imperial College London in Britain.
"We can see this leapfrogging happening now, for example with the Guatemalan howler monkey, which was classified as being on the 'least concern' list in 2000 but which moved to the 'endangered' list in 2004 as it lost much of its forest habitat," he said in a statement.
Now most conservation resources are spent in regions where the natural system has been impaired, but repairing damage tends to be more expensive than preventing it, the researchers explained.
"Latent risk hotspots might provide cost-effective options for conservation," said Andy Purvis, a co-author of the study, "They're places that are relatively intact, and preventing damage is likely to be cheaper and more effective than trying to repair it."