Abstract:

Daily travel distance of primates is an important factor to evaluate their home range size. The effects of annual change in group size, human disturbances and weather on daily travel distance of a group in Sichuan snub-nosed monkey (Rhinopithecus roxellana) was studied for eight seasons from April 2001 to January 2003 in the Qianjiaping area of Shennongjia Nature Reserve, Hubei. The group was successively followed for 30 days every season. The group’s straight-line distance method was used to determine the daily travel distance of the group. Annual group size was investigated and information on human disturbance and weather was collected. The results showed that group size increased by 14% from 2001 to 2002. There was no difference in the daily travel distance of the group between the two years, suggesting that annual change in group size had little effect on daily travel distance. The group traveled a longer distance on days with hu-man disturbance than on days without in the same season. Multiple stepwise regression analysis showed that there was no relationship between the daily travel distance of the group, the proportion of time spent sunning and the proportion of cloud cover during the day in different seasons. The daily travel distance was nega-tively correlated with percent of time with rain or snow during the day in winter and spring but not in sum-mer and autumn, indicating that the group reduced daily travel distance during rainy or snowy days in winter and spring. The seasonal difference in effects of rain or snow on the daily travel distance may be related to reproductive features of the monkeys. The results suggest that human disturbance may have a harmful effect on the monkey population, and that long periods of precipitation in spring and winter can represent crises for the monkeys.