LAUSR

Abstract Population size is a critical indicator used to assess the demographic profile and conservation status of animal species living in disturbed habitats. Using GIS technology, we calculated the remaining habitat area and estimated the population size of the Guizhou snub-nosed monkey (Rhinopithecus brelichi), an Endangered primate endemic to China. The last remaining population of this species resides in the Fanjingshan National Nature Reserve (FNNR). We combined data on forest cover and patterns of group movement to estimate the size and continuity of their habitat. The results indicated that the area of remaining suitable habitat is 69.6 km2. However the monkeys are confined to an area of only 27.8 km2 (6.6% of the total reserve area of 419 km2) located in the northern part of the reserve. The remaining 28.5 km2 of suitable habitat is located in the southern part of the reserve and inaccessible to the monkeys because of the recent construction of an aerial tram. Based on estimates of population density, we calculated that the remaining world’s population of R. brelichi is approximately 125–336 individuals. In order to protect this species from extinction, we recommend that the highly fragmented evergreen and deciduous broadleaf mixed forest adjacent to the remaining troop’s home range be given protected status and an active program of forest regeneration in this area be implemented immediately.