The tiger has an estimated population of 3,400-5,000 individuals; the giant panda, 1,000-2,000; the Sumatran rhino, 250; the North Atlantic right whale, 200-250; and the California condor, 170. A new study shows that none of these species is safe from extinction yet, although each has received considerable conservation attention compared to most imperiled species.
The study published in Biological Conservation found that conservationists are targeting minimum numbers of population that are far too small to guarantee safety for a species in light of continued environmental upheaval, including climate change and habitat loss.
"Conservation biologists routinely underestimate or ignore the number of animals or plants required to prevent extinction," says lead author Dr Lochran Traill, from the University of Adelaide's Environment Institute.
The common figure used for conservation efforts is known as the '50/500 rule'. According to this idea, a species needs fifty adults to ensure the species isn't inbreeding and 500 individuals to avoid extinction due to environmental change.
"Our research suggests that the 50/500 rule is at least an order of magnitude too small to effectively stave off extinction," says Traill. "Often, [conservationists] aim to maintain tens or hundreds of individuals, when thousands are actually needed. Our review found that populations smaller than about 5000 had unacceptably high extinction rates. This suggests that many targets for conservation recovery are simply too small to do much good in the long run."
However, Traill adds that the research in no way suggests that species with populations under 5,000 are beyond help.
Mongabay.com is an environmental science and conservation news website.
