Abundance Of Diet Plants And Seasonal Changes Of Diet Nutrients Of Rhinopithecus Roxellana In Shennongjia Natural Reserve, China

The primates living in temperate region often suffer from dietary stress during food scarcity period. The golden snub-nosed monkey (Rhinopithecus roxellana) lives in such a region. Nutritional ecology is the core of primate conservation because primates must acquire adequate nutrition under a suite of environmental and social constraints to reproduce successfully. The Sichuan snub-nosed monkey are usually arboreal and choose leaves as its foods. Is there nutrient intake difference between different seasons?We investigated the vegetation of habitats and the diet food species for R. roxellana at Qianjiaping in Shennongjia Nature Reserve (SNR), western Hubei Province, China, which is located in the eastern limit of the golden snub-nosed monkey’s range. We presented data on food composition and abundance in relation to habitat choice and discussed its influence on conservation of the snub-nosed monkey. We chose critical and representative vegetation in this zone, and set 88 plots (20*20 m2) with elevation gradient and collected floristic data from 2010 to 2012. Based on the dominant tree species, we divided the habitats into three vegetation types and 12 community types. They are the deciduous broadleaved forest (DBF) 1-7, conifer broadleaf forest (CBF) 1-4 and shrub forest (SF). Broadleaf forests contained more diet species for R. roxellana than conifer-broadleaf forest, and the habitat at lower elevation provided more diet species than that at higher elevation, but the food plants at lower elevation were poor in amount and uneven in distribution across the site. Although the monkeys could eat many plant species, but the food plants in its habitat were not enough and unevenly distributed. We therefore suggest improving the forest structure for these monkevs by cultivating food plants or by limiting logging to increase the amount of available food.In order to test and to understand the effects of the chemical of plant on food choice, and the correlations between food species and food choice, data were compiled on leaf chemistry in Shennongjia. We collected leaves and fruits (or seeds) in three seasons (Spring, Summer, And Autumn). We analyzed samples for contents of crude protein (CP), crude lipid (CL), acid detergent fiber (CF), ash (ASH), and the protein/fiber (PFR), and compared the macronutrients of samples among different seasons.The crude fiber content was the lowest in spring (22.13% plus or minus 6.86%, n= 15) and the highest in summer (32.04% plus or minus 7.82%, n=26). In spring, Sichuan golden monkey intook the minimum of crude fiber but highest protein. It may be because the monkey intake more young leaf which contain more protein than fiber. Across all three seasons, the ratio of protein and fiber was the highest in spring (1.15% plus or minus 0.48%, n= 15), and nearly the same in summer (0.33) and autumn (0.35). By comparing nutrients of food plants in different seasons, we found that protein (F= 66.256, p< 0.01), fiber (F= 4.154, p< 0.05) and the protein/fiber ratio (F= 26.144, p < 0.01) were significantly different among three seasons, and there were no significant differences regarding fat content (F= 1.754, p> 1.754) and ash (F= 2.804, p> 2.804).In spring the content of crude fat is significantly different among different food plants (t= 3.418, p< 0.01, two tailed), but there was no difference in term of crude protein, crude fiber, ash and protein fiber. The situation was similar between spring and summer. In summer, the amounts of crude fat were significantly different among different plants (t= 2.597, p< 0.05, two tailed), and in autumn, there was no significant nutrient differences between food source plants.By analyzing the correlation of food plant nutrients, we found that there were significantly positive correlation between crude protein and ash (rs= 0.528, p< 0.01, n= 57), and between crude protein and protein/fiber ratio (rs= 0.831, p< 0.01, n= 57). Crude protein and fiber were significantly negatively correlated (rs= 0328, p= 0.328< 0.05, n= 57). There was no correlation between crude fat and other nutrient. Fiber and PFR (protein/fiber ratio) were negatively correlated (rs= 0.720, p< 0.01, n= 57), and they had no correlation with ash.Our data on the monkeys’ food choice throughout a year basically support the protein to fiber model, but show that there is a seasonal variation in ingested macronutrients of diets. The protein content decreased from spring to autumn, and the fiber almost keeps a fixed level. The Sichuan snub-nosed monkey chooses plants with higher protein and low PFR in spring when there is a period of food scarcity. When foods are abundant (contain summer and autumn), the monkey chooses lower protein and higher PFR plants. Thus, the food nutrients are deterministic factors which influence the community ecology of Sichuan snub-nosed monkey. The present study provides useful information to conservation of the Sichuan snub-nosed monkey.