Molecular censusing doubles estimate of key giant panda population

Employing a noninvasive technique that uses genetic information to identify individual pandas in the wild, researchers have revised--upward--size estimates of a key giant panda population in China. The research is reported in the June 20th issue of Current Biology by a team of scientists from China and the UK, including Fuwen Wei of the Institute of Zoology, Chinese Academy of Sciences and Michael W. Bruford of Cardiff University.

The giant panda is one of the world's most charismatic endangered species and has an emblematic status for the conservation movement worldwide. Its attraction stems in part from its elusive nature: A wary creature with an unusual dietary dependence on bamboos, it is now found only in a restricted mountainous region in China. These characteristics have also shielded important knowledge needed to save the panda from extinction.

Understanding population trends for giant pandas has been a major task for conservation authorities in China for the past thirty years, during which three increasingly sophisticated national surveys were carried out. The first two revealed alarming evidence for declines across the giant panda's range. However, the most recent survey, completed in 2002, showed the first evidence of a recovery, thanks largely to protection measures taken by the Chinese government, including support for a network of natural reserves and strictly enforced bans on poaching and deforestation.

Nonetheless, given the variable accuracy of traditional ecological census methods, other approaches to accurately estimating panda population size are needed. In the new work, the Chinese and UK researchers re-examined the ecological estimate for a key reserve population of giant pandas in Wanglang Nature Reserve. To boost the accuracy of their study, they used recently developed noninvasive techniques, including DNA sequence profiling from fecal samples, that have been successfully used for censusing wild animal populations. The researchers found that the most recent survey likely underestimated the giant panda population by more than 50%. Moreover, the population showed no genetic trace of a demographic "bottleneck" in the recent past, implying that the population may not have been diminished to such tiny numbers as commonly feared.

If these results were to be replicated in other key reserves (and the authors state that this is not unlikely), then there may now be many more giant pandas remaining in the wild than previously thought. This finding indicates that the species may have a significantly better chance of long-term viability than recently anticipated, and that this beautiful animal may have a brighter future.

The researchers include Xiangjiang Zhan, Ming Li, and Fuwen Wei of the Institute of Zoology (IOZ), Chinese Academy of Sciences in Beijing, People's Republic of China; Zejun Zhang of the Institute of Zoology (IOZ), Chinese Academy of Sciences in Beijing and China West Normal University in Sichuan, People's Republic of China; Benoit Goossens and Michael Bruford of Cardiff University in Cardiff, United Kingdom; Youping Chen of Wanglang Nature Reserve in Sichuan, People's Republic of China; Hongjia, Wang of Sichuan Forestry Department in Sichuan, People's Republic of China.

Zhan et al.: "Correspondence: Molecular censusing doubles giant panda population estimate in a key nature reserve." Publishing in Current Biology 16, R451-2, June 20, 2006 www.current-biology.com

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