Distribution and population status of Macaca mulatta in Shaa

      Rhesus macaque(Macaca mulatta), a rare primate in Shaanxi Province, China, has exhibited a rapid population decline throughout its range in recent decades. A population survey conducted in 2006, however, found the species to be widely distributed throughout the counties of Zhenba, Xixiang and Nanzheng, with the majority of resident population (approximately 385-415 individuals) located in Xixiang Micangshan National Nature Reserve. Macaca mulatta is a group-living primate, with groups consisting of several units, each of which is comprised of several breeding males, multiple females, and their offspring. This study presents the results of a population survey conducted from August to December 2013 that aimed to describe the distribution, behavior, social structure, and habitat preferences of Macaca mulatta in Micangshan National Nature Reserve, Shaanxi Province. Prior to beginning the survey, we interviewed local farmers and villagers to estimate and identify the approximate distribution of the macaque population in the nature reserve, following which we were able to choose the particular geographic region and the season to conduct the survey. During the study period, the population was monitored daily (from 7:00 to 18:30) by counting all individuals observed along a V-shaped transect route through the study site. When a group was spotted, we recorded the time and location of the encounter, altitude at which the group members were observed, age and sex of all individuals in the group, direction the group was moving, habitat structure at that location, and where relevant, plant species on which the group was feeding. Our survey revealed that between 460 and 500 individuals, comprising 12 groups, reside within the reserve. This is an increase of one group and approximately 80 individuals compared to those recorded during the survey in 2006. This finding suggests that the population of Macaca mulatta in the province is increasing, a trend that is likely the result of the establishment of the Shaanxi Micangshan National Nature Reserve in 2002. During the survey period, we were able to determine the demographic composition of five groups (comprising 209 individuals). We found that on average, 45.93% of individuals in a group were adults, while 34.45% were juveniles, and the remainder (19.61%) infants. The ratio of adult to young was 1.33, while the sex ratio in the groups was 0.36 (males to females). Social groups were distributed primarily around the villages of Chayuan (four groups) and Loufangping (three groups), areas where the human population density is lower as a result of government policy encouraging people to leave. Our observations also revealed distinct habitat preferences for this species. Groups were observed to be most active in areas with rock cliffs and along the farm belts at higher altitudes, and they displayed preferences for broad-leaved forests, shrub-border zone, and deciduous broad-leaved forests of the central mountains at altitude ranging from 700 to 1600 m. To ensure the continued presence of Macaca mulatta, the following conservation measures should be implemented: (i) standardized long-term monitoring of the population structure, distribution, and habitat preferences of this species should be instigated; (ii) because habitat destruction and fragmentation is the main factor threatening the survival of this species, actions to facilitate and increase interactions among different troops should be implemented to avoid inbreeding within troops; and (iii) measures should be undertaken to increase and enforce existing laws protecting Macaca mulatta.