Genetic diversity of the endangered scaly-sided merganser (Mergus squamatus) in the wintering habitat of central-southern China.

The scaly-sided merganser (Mergus squamatus), found in temperate East Asia, has been reduced to a very small population. Central and southern China are its main wintering habitat. However, populations have declined greatly since the 1980s due to habitat loss and degradation, and poaching. To meet the urgent need for up-to-date conservation information, we examined RAPD DNA markers from 156 specimens in 6 populations in Jiangxi Province. We found that genetic diversity (based on individual similarities) is in fact low; molecular variance between populations ranged from 0.137 to 0.347. Genetic similarity ranged from 0.683 to 0.866. In conclusion, the geographical pattern of genetic diversity supports the long-term refugial status of the scaly-sided merganser in central-southern China; strong conservation measures should be taken to maintain the merganser in this region.