The range and habitat suitability of François' langur (Trachypithecus francoisi) in Mayanghe Nature Reserve, China

The François' langur (Trachypithecus francoisi) is an endangered primate living in limestone forests in Vietnam and China. From October 2017 to August 2018, the habitat preferences and the range of the Francois' langur were surveyed in the Mayanghe Nature Reserve, Guizhou, People's Republic of China. To estimate the range and predict suitable habitat of François' langur, a Gaussian normal kernel density estimation and species distribution models (BIOMOD2) were used along with data on environmental variables and records of the langur's occurrence. The total range of François' langur in the reserve is 68.76 km², accounting for 22.1% of the total area of the reserve. The elevation of the main utilisation area is 500-800 m, accounting for 48.53% of the total area of the reserve. The maximum slope utilised is 20°-30°, 30.19 km² and accounting for 30.56% of the total area. The habitat used is largely distributed along valleys, preferred broad leaf forest, lower elevation, and close to rivers. Broad leaf forest is the main habitat type utilised, totalling 25.57 km² and accounting for 37.19% of the total area. Our models predicted that the suitable habitat in the reserve is 62.46 km², accounting for 20.08% of the total reserve area, with 32.93-km² suitable habitat occurring in the core zone, 22.44 km² in the buffer zone, and 7.02 km² in the experimental zone. Our results indicate that only limited suitable habitat (51%) adverse reserve zoning exists in the Mayanghe Nature Reserve of François' langur.