A stable, demographically structured wild population of the Chinese Water Dragon (Physignathus cocincinus) has been confirmed in Tongle Dashan Provincial Nature Reserve, Yunan County, Yunfu City, Guangdong — a major milestone for regional biodiversity conservation. This significant finding was recently announced by the reserve's Management Office following a targeted survey of the species.
Using line transect methods during nocturnal surveys, the research team repeatedly observed individual lizards in the Tongle Dashan area. Along a transect of approximately four kilometers, the team recorded 16 individuals representing different age classes: four adults, nine subadults, and three juveniles. This age distribution demonstrates that the population possesses robust reproductive capacity and generational continuity, constituting a healthy and stable resident population.
The Physignathus cocincinus is a large iguanid species endemic to China, and is recognized for its strict ecological requirements regarding water quality and forest integrity. Due to these sensitivities, it is widely regarded as both a flagship species and an indicator species for forest–stream ecosystems.
The discovery of a stable population within Tongle Dashan carries significant ecological and scientific importance. First, it provides compelling evidence of the superior ecological conditions of the area: the population's persistence indicates dense forest cover, clean water resources, and an intact ecosystem, thereby validating the effectiveness of ongoing conservation efforts.
Additionally, it enhances the biodiversity value of the reserve. As a species listed under China's Category II National Key Protected Wildlife, classified as "Vulnerable (VU)" by the IUCN Red List, and as "Endangered (EN)" by the China Biodiversity Red List, its confirmed presence substantially elevates both the conservation and research importance of the reserve.
Moreover, it provides essential baseline data for future studies. This population offers a critical research site for investigating the distribution, ecological habits, and demographic dynamics of Physignathus cocincinus in western Guangdong and contributes valuable reference material for nationwide conservation strategies for the species.
Author: Liu Hanze (intern), Wei Shen
Photo: Nanfang Plus
Editor: Wei Shen, James Campion, Shen He
