White-Headed Langur and the Effects of Habitat Fragmentation

JUN . 05 2017
Peking University, May. 24, 2017: In May 2017, the Yao Meng research group of PKU School of Life Science published a cover article entitled "Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus" in Heredity magazine (Heredity 118 ( 6): 542-553). This is the first comprehensive study that has evaluated the genetic diversity and genetic structure of the white-headed langur (Trachypithecus leucocephalus) and environmental factors leading to its genetic differentiation using microsatellite and mitochondrial DNA.

Habitat fragmentation is likely to result in reduced genetic diversity of wild populations and increased genetic differentiation. The white-headed langur lives in the southwestern karst mountain area of Guangxi Zhuang Autonomous Region, and it one of China's endemic species. There are only 1000 wild white-headed langurs which can be found in a small area surrounded by Zuojiang River, Mingjiang River and Sifang Ridge. The white-headed langur has been listed as a national first-level protected animal and as a Critically Endangered (CR) species by International Union for Conservation of Nature (IUCN). However, as human population increases, their need for land and resources also increases. Their land is gradually being farmed, which destroys the continuity of the white-headed langur’s habitat. This study evaluates the effects that habitat fragmentation imposes on the genetic diversity and genetic structure of white-headed langurs. Corresponding protection and management suggestions were put forward according to the research results.

A total of 214 independent individual samples from 41 social groups of Chongzuo and Fusui show where the white-headed langur mainly comes from. Fifteen species-specific polymorphic microsatellites, one DEAD-box protein of gender difference and the genotype data of a mitochondrial DNA control region were obtained. The results show that the genetic diversity of the white-headed langurs are less than that of other primates whose endangered state and population are similar to white-headed langurs. The white-headed langur population genetic structure was divided into three kinds: Chongzuo (CZ), Fusui Jiuchongshan (FS-JCS) and Fusui Buzun (FS-BZ). The genetic differentiation of the three genetic populations was obvious, and their individual mobility was low. Large non-habitat areas (farmland, village, etc.) and geographic distance are the main landscape factors that determine the population genetic structure. To protect the genetic diversity of the populations and guarantee the species' long-term survival and evolutionary potential, we should promote natural gene exchange between monkeys, and avoid genetic isolation of small populations by restoring habitat vegetation, reducing human activities in habitats, and establishing migratory corridors between adjacent habitat areas.

Yao Meng, a researcher in the PKU School of Life Sciences, is the corresponding author of this paper. Wang Weiran is the first author, and Qiao Yu made an important contribution to this study. Professor Pan Wenshi and researcher Li Sheng are co-authors. This study was supported by the National Natural Science Foundation of China (Grant No. 31272329 and 31572283).

Written by: Qian Kang
Edited by: Wang Yuqing/Gan Zhonghao
Source: PKU News (Chinese)