And without the nature reserves erected over the past half-century, more would be gone.
“Conservation is working, there is just not enough of it,” says study author Ana Rodrigues of France‘s Centre d’Ecologie Fonctionnelle et Evolutive. “Now is the time to scale up conservation.”
The five-decade survey of the extinction status of 25,780 vertebrate species, roughly half of all backboned animals, was released by the journal Science. Led by Michael Hoffmann of the United Nations Environment Programme, the results find that almost one-fifth of those species are threatened with extinction (from 13% of birds to 41% of amphibians) — meaning either there are fewer than 50 individuals left, or the species’ chances of extinction are 50% or greater within 10 years. The declines are mostly tied to expanding farmland, overlogging, overfishing and competition from invasive species.
Another 52 vertebrate species move closer to extinction in a typical year.
Simply by comparing 50-year population trends before and after conservation measures such as regulation and erection of preserves, however, the survey shows 18% more species would be threatened with extinction had the measures not been undertaken. Some success stories:
•Humpback whale. Now protected by whaling conventions, populations have recovered to around 80,000, from about 5,000 in the 1960s.
•California condor. Once numbering only 22, now more than 300 exist, thanks to captive breeding efforts.
•Przewalski’s Horse. Increased from 13 or 14 living in 1945 to more than 1,800 today.
“This is a really conservative estimate of conservation’s effects,” says ecologist Taylor Ricketts of the World Wildlife Fund in Washington, D.C.
“The extinction findings are in line with past reports, but finding a basic effectiveness for conservation worldwide is the bottom line news,” he says.
The results, being presented today at the 10th Conference of the Parties to the Convention on Biological Diversity (CBD), in Nagoya, Japan, mean that 193 nations have failed to meet a 1993 agreed-upon goal “to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on Earth.” Representatives of those nations are at the meeting to discuss a new agreement on protecting species.
Economists estimate that biodiversity brings about $33 trillion in annual benefits worldwide to humanity, notes study co-author Stuart Butchart of the United Kingdom‘s BirdLife International, through cleaner water, pest consumption and other environmental benefits. “Money spent on conservation isn’t wasted, it’s cost-effective,” he says.