Biodiversity: Without Efforts, Losses Would Have Been Worse

Liz is a staff writer for Science.

Eight years ago, the parties to the Convention on Biological Diversity agreed to significantly reduce the rate of loss of biodiversity by 2010. That has not happened, but the bad news about biodiversity would be worse if it were not for conservation. A study released today online in Science has quantified how much protective strategies have worked to slow the decline in birds, mammals, and amphibians, concluding that the rate of deterioration would be 20% worse.

Michael Hoffman of the International Union for Conservation of Nature's Species Survival Commission and more than 170 colleagues looked at the status of more than 25,000 vertebrate species in the IUCN Red List of Threatened Species, evaluating the change in status over time. They found that 20% of the world's vertebrates are in trouble. And more than 50 species of birds, mammals, and amphibians slip closer to extinction each year, with Southeast Asia suffering the greatest losses.

However, the study found that 68 of 928 species whose Red List status has changed over time had a better prognosis; and in 64 cases, conservation provided the needed boost. Effective programs include those that remove invasive species, such as introduced predators from small islands, thereby saving native birds, and whaling bans. Successes also include the reintroduction of the California condor, the Black-footed ferret, and Przewalski's horse, all previously extinct in the wild. Overall, numbers are growing in some 9% of threatened species, says Hoffmann. "The 2010 biodiversity target may not have been met, but conservation efforts have not been a failure," he and his colleagues wrote.