Predicting the potential distribution change of the endangered Francois’ langur (Trachypithecus francoisi) across its entire range in China under climate change

Abstract

The Francois’ langur (Trachypithecus francoisi) is a rare and endangered and the indicated primate species distributed in karst area in northern Vietnam and southwestern China. However, holistic conservation management has been hampered by research limited to specific nature reserves or sites. Building a comprehensive map of potential distribution for the Francois’ langur is essential to advance conservation efforts and ensure coordinated management across regions. Here, we used 82 occurrence records of Francois’ langur surveyed in Guangxi, Guizhou, and Chongqing from 2017 to 2020, along with 12 environmental variables to build the potential habitat model under current and future climate (for the periods 2021-2040, 2041-2060, 2061-2080, 2081-2100) using maximum entropy models (MaxEnt). Our results indicated that 1) precipitation- and temperature-associated bioclimatic variables made the greatest contributions to the distribution of Francois’ langur, vegetation, water source and anthropogenic variables were also important factors affecting the distribution of Francois’ langur; 2) 144207.44 km2 potential Francois’ langur suitable habitat across the entire range in China was estimated by the current model, moderate- and high-suitability habitat accounted for only 23.76% (34265.96 km2) of the predicted suitable habitat and mainly distributed in southwest Guangxi, east of Chongqing and the border between Guizhou and Chongqing; 3) the suitable habitats of Francois’ langur will dramatically contract under future climate change and the habitat centroid will move in the southeast direction with the shifting distance about 2.84km/year from current to 2100. The habitat prediction of Francois’ langur and related drivers proposed in this work will provide essential insights for future conservation of this species, which is, not only existing distribution areas should be monitored and protected, but also conservation beyond existing habitats should be a focus of effort, especially future expansion areas, to ensure effective and timely protection under climate change and anthropogenic pressures.