土壤pH值对秦岭川金丝猴食土行为的影响

食土行为广泛存在于灵长类动物中，关于灵长类的食土行为有很多功能性的假说，包括补充矿物质、有毒物质吸附、抗腹泻、抗体内寄生虫感染及肠胃酸性中和等假说。为了解秦岭川金丝猴取食黏土的影响因子和功能假说，于2013年9月至2015年1月采用扫描观察法和瞬时记录法收集食性数据，记录取食黏土个体的性别年龄及取食位置，并采集秦岭川金丝猴取食的黏土和对照黏土样品。于2016年07月采用电位法测定土壤样品的pH值。食性结果表明不同性别年龄个体，从1岁的婴幼猴到成年个体都存在取食黏土的行为；秦岭川金丝猴取食黏土的pH显著高于对照样品的pH值。因此，本研究结果与肠胃酸性中和假说更为契合，秦岭川金丝猴取食偏碱性的黏土，有利于中和取食大量芽和叶摄入的酸性物质。

Effect of soil pH on geophagy in golden snub-nosed monkey (Rhinopithecus roxellana) in Qinling Mountains

Geophagy is widely reported in primates, and several functional hypotheses have been proposed to explain this phenomenon, including supplementation of minerals, adsorbance of toxic substances, anti-diarrhea effects, protection against parasitic infections in the body, and balancing the acid in the intestines and stomach. In order to improve our knowledge of impact factors and function of geophagy in golden snub-nosed monkey (Rhinopithecus roxellana), we collected diet and geophagy data on golden snub-nosed monkey via a scan-sampling at 5-mins interval, from Sept. 2013 to Jan. 2015 in Qinling Mountains. The site of geophagy, and the sex and age of individuals who were eating clay were recorded.  We also collected samples of clay and control soil.  The pH of the soil simples was measured using potentiometry in Jul, 2016. We found all individuals from different sex-age groups including infants ate soil. We also found that the clay had higher pH than did control soil. Therefore, our result suggested that golden snub-nosed monkeys consumed soil with higher pH, which may serve to balance acids in the intestines and stomach, A high frequency of clay-eating was coincident with high percent of bud and leaf in the diet.