Human overexploitation and extinction risk correlates of Chinese snakes
30 June 2019Chen, Chuanwu; Qu, Yanfu; Zhou, Xianfeng; Wang, Yanping
China is one of the countries with the richest snake biodiversity in the world. However, about one-third of all 236 species are now considered threatened, partially due to the intense human overexploitation. Despite that, to date, no study has explicitly investigated the patterns and processes of extinction and threats of Chinese snakes, or between human exploited and unexploited snake subgroups. We addressed the following three questions: (1) which snake families proportionally include more human exploited species than expected by chance? (2) which species traits and extrinsic factors are correlated with their extinction risk? (3) are there differences between human exploited and unexploited species in terms of patterns and processes of extinction? We found that the family Elapidae contained a significantly higher number of exploited species. Considering eight species traits and four extrinsic factors, we performed phylogenetic correlation tests, finding that small geographic range size, large body length, oviparous reproduction, diurnal activity, and high human exploitation were important in determining the extinction risk of all Chinese snakes. Moreover, human exploited snakes had a higher percentage of threatened species and large-bodied species than unexploited snakes. Extinction risk of human exploited species was related to body length, reproduction mode and activity period, whereas that of human unexploited species were associated with geographic range size, microhabitat, and annual temperature. Overall, we highlight the phylogenetic non-random exploitation of snakes, and different factors underlying species response to human overexploitation. We suggest that conservation priority should be given to exploitation-prone families and species with extinction-prone traits, as identified in this study. Moreover, human exploited and unexploited species should be managed considering different strategies since their extinction risk was associated with different ecological traits. Conservation actions should also focus on preventing human threats, such as overexploitation, for the effective preservation of Chinese snakes.