The WWF's Living Planet Index reported an average 68 percent fall in the populations of all animals monitored, a grim figure that made headlines worldwide. AFP/World Wild Fund for Nature/Ho
PARIS - The population of most wild animals with a backbone -- mammals, amphibians, birds, reptiles and fish -- is stable, scientists said in a finding sharply at odds with a benchmark report issued every two years by environmental group WWF.
Looking at 14,000 vertebrate populations monitored by WWF since 1970, researchers found that if the one percent suffering the worst declines are removed from the equation, the remaining populations, grouped together, are holding steady in terms of overall numbers.
In September, the WWF's Living Planet Index reported an average 68 percent fall in the populations of all animals monitored, a grim figure that made headlines worldwide.
"Collapsing all population trends into a single value can give the impression that everything is declining," Brian Leung, senior author of the new study and a professor at McGill University in Canada, told AFP.
"However, the image of a global 'biodiversity desert' is not supported by the evidence."
There are in fact regions where most species within certain groups are on a clear downward spiral, such as birds in the Asia-Pacific region and reptiles in the Americas.
But including them in an overall average can be misleading, Leung said.
"The Living Planet Index metric does not actually show that 68 percent of all populations have been lost," he noted by email.
"Unfortunately, it is hard to not leave with that impression."
Asked to comment on the report, WWF referred AFP to the Zoological Society of London (ZSL), which co-authors the flagship Living Planet reports.
ZSL scientist Robin Freeman, also a co-author of the new study, published in Nature, acknowledged in a blog post that "removing these clusters (of extreme decline) leave a distribution of population that appears, on average to be stable."
"However, this doesn't mean that the remaining 99 percent of all populations in the Index are doing fine."
WWF has put out 13 Living Planet reports tracking changes in vertebrate populations since 1998.