Winter Feeding Tree Choice in Sichuan Snub-Nosed Monkeys (Rhinopithecus roxellanae) in Shennongjia Nature Reserve, China

Abstract

We investigated patterns of winter feeding tree choice in 4 groups of Sichuan snub-nosed monkeys (Rhinopithecus roxellanae) in Shennongjia Nature Reserve, China. We collected data during 2 winters from 1998 to 2000. The monkeys used mature forest, young forest and shrub forest, but not grassland. Groups used tree species in a significantly nonrandom pattern. There was a similar composition of preferred tree species between different habitats for each group and among the same habitat types for different groups. They preferred Abies fargesii, Pinus armandii and Salix walliciana for foraging. The 3 species occur in varying degrees of abundance in different habitats and were used differently by the 4 groups. The difference is probably due to interhabitat differences in availability of tree species, in addition to microclimate. The mean circumference of a tree had little effect on its preference score, but preferred species tend to be larger. A Wilcoxon signed-rank test indicated that the percentage of trees used and average number of feeding bites per tree is significantly greater for larger trees. For all trees in a given habitat, the percentage of trees used and average number of bites per tree have a significant positive correlation with average tree circumference. Our results indicate that Rhinopithecus roxellanae prefer to feed in large trees more than small trees in a given habitat, thereby preferring mature forest habitat. There is also a group-size effect; larger groups used higher-quality habitats than those of smaller groups. Both tree species and size are the major determinants of feeding choice, but tree species is more important than tree size. Our results have at least three implications for winter habitat conservation of Sichuan snub-nosed monkeys. Conservation efforts should be focused on mature forest because it is better habitat at Rhinopithecus than young forest, as long as the same tree species are present. Secondly, Pinus armandii, Abies fargesii and Salix walliciana should be conserved as top priority in forest communities. Third, the largest trees in each habitat should be given greatest possible protection.