The golden snub-nosed monkey is found in groups ranging in size from 5–10 individuals to bands of about 600. The social organization of this species can be quite complex. The one-male-units (OMUs) are the basic social unit within groups of golden snub-nosed monkeys with many of the OMUs forming a bigger group. These multi-tier societies consist of several OMUs that include one adult male plus a number of adult females and their offspring. Some observers have even come to conclude that these large foraging groups are multi-male and multi-female societies. Females of the golden snub-nosed monkey are usually observed to form several close associations with other females. However, in conflicts against other units in the surrounding site, both males and females support each other, while also protecting their young (usually observed at a distance by putting the young in the center of the pack). Protecting the young is a group effort. Mothers often have helpers assisting them with the care of their young. When faced with danger from a predator such as the
northern goshawk (
Accipiter gentilis), the young are placed at the center of the group while the stronger adult males go to the scene of the alarm. The rest of the day, the members of the group remain closer to one another with the young protected at the center. There is little information available on the sleeping cluster patterns of the
Sichuan snub-nosed monkeys. However, in a detailed observation of the free-ranging band in the
Qinling Mountains in central China, results have suggested that winter night activity of
Rhinopithecus roxellana is a compromise between antipredator and thermoregulatory strategies and an adaptation to ecological conditions of their
temperate habitat. Keeping warm is critical for survival in freezing temperatures, but their thick coats can provide this warmth as well as sleeping in these clusters. Monkeys often sleep in the lower stratum of the tree canopy, avoiding the upper canopy where it is cold and windy. They form larger sleeping clusters at night than in the daytime. The most common types of night-sleeping clusters were adult females and their young, followed by adult females with other adult females. In primate research, although male–male competition for mates and female
mate choice are the common causes of
sexual selection, female–female competition over males is especially important in polygynous species. The Sichuan snub-nosed monkey is a seasonal breeding species of
colobine endemic to China, and lives in a multi-level social system. Because the basic social and reproductive unit is the harem or one male unit (OMU), which consists of a single resident male, a number of adult females, sub-adult females, juveniles and infants, it has been suggested that sexual competition in this
polygynous species is skewed. Females faced with multiple competitors will exhibit a high level of
sexual competition, while the single resident male will not experience within-group sexual competition. They also have up to 3 babies.
Diet The golden snub-nosed monkey eats (from greatest to least amount)
lichens, young
leaves,
fruits or
seeds,
buds, mature leaves,
herbs,
bark, and
flowers. This diet varies from season to season, showing a correlation once again between food availability and home range. This diet also shows a complicated seasonal variation. The monthly diet of monkeys at Shennongjia Nature Reserve varies from primarily
lichen eater between November and April, to a mixture of
folivore and lichen eater from May to July, and to a mixture of
frugivore (or seed eater) and lichen eater or primarily lichen eater between August and October. For this seasonal variation, the amount of lichens consumed appears to decrease in the summer with the greater availability of fruit or seeds. The monkeys' preferred lichen species seem to grow on
Cerasus discadenia,
Salix wallichiana, and
Malus halliana. Lichens are found in great profusion on dead trees. Monkeys at Qingmuchuan Nature Reserve have not been observed feeding on lichen; during the winter they feed mostly on leaves, bark, and buds, and during the summer they feed mostly on the fruit of the
giant dogwood. This primate prefers to forage in larger trees of a tree species, and spends most of the time using primary forest and young forest, rarely uses shrub forest and does not use grassland. ==Conservation==