The Study Of Nutrient Balancing Among Several Provisioned, Free-ranging Sichuan Snub-nosed Monkeys (Rhinopithecus Roxellana) In Qinling Mountains

The theory of nutrient balancing claims that balanced nutritional intake is sufficient for the survival and reproduction of animals. However, people know little about the long term mechanism of nutrient balancing in non-human primates. Specially, for Sichuan snub-nosed monkeys(Rhinopithecus roxellana) which have strict social rank and seasonal diet, their long term nutrient balancing mechanism is still unknown. Therefore, to investigate the food intake and nutrient balancing strategies of Sichuan snub-nosed monkeys, we have conducted quantitative study on the nutrient intake of snub-nosed monkeys in Qinling area by following individual monkeys in consecutive days.This study took place from November to December in 2014 and April to May in 2015 in Zhouzhi National Level Nature Reserve. Six snub-nosed monkeys (two males, two adult females not in lactation, two adult females in lactation, and every two individuals in the same category have significant rank difference) were followed in about six consecutive days each. All their activities, species and amount of their food intake were recorded. During our focal follows, their total number of food types were 128, including 2 human feeding species and 63 natural species. We have tested the nutrients of their food(e.g. crude protein, crude fat, neutral detergent fiber and ash), calculated daily individual nutrient and energy intake, and analyzed the nutrient intake individually by the Geometric for Framework.Our study results indicate:in the same season, the daily dry food and energy intake by each individual monkey varies, and the dry food and energy intake in winter is higher than that in summer. Our study also demonstrates that:1. Snub-nosed monkeys can balance their daily nutrient intake to maintain and assure a stable ratio of energy from non-protein to the energy from protein, but the balancing mode varies between individuals; 2. the nutrient balance is not necessarily achieved in a single day but may reach within several days, which shows periodic pattern; in winter (breeding season) when food is insufficient, this balancing period is relative long and no apparent pattern, while in spring when food is sufficient, the balancing period is short, such as 1-2 days; 3. during winter when food is insufficient, the social ranks of the monkeys have significant impact on their food and nutrient intake strategies; while in spring when food is sufficient, the rank effect is not obvious; however, further study is necessary to draw a concrete conclusion on the rank effect because of the small number of samples in our current study.