季节和等级顺位对雄性黄山短尾猴粪样皮质醇水平的影响

在长期的进化选择压力下,灵长类动物大多数群居生活,群体中的动物个体也面临来自群内成员强度不一的社会压力,压力大小的重要生理指标通常用其体内的皮质醇水平的变化来衡量.季节性繁殖的黄山短尾猴(Macaca thibetana),群体内的个体有严格的社会等级,是研究等级顺位与社会压力水平之间关系的理想研究对象.我们采集13只...

Effects of seasonality and social ranks on fecal cortisol levels in male Tibetan macaques(Macaca thibetana)

Many primate species are social, a consequence of long-term evolutionary processes.Despite natural selection favoring sociality, intragroup competition can generate stress for individuals.Cortisol level is one physiological indicator of an individual's stress.Seasonally-breading Tibetan macaques(Macaca thibetana) are ideal candidates for the investigation of the potential relationships between social stressors, cortisol levels, and dominance rank.We collected 325 fresh feces from 13 males in Huangshan, Anhui Province, China, and quantified cortisol levels from the fecal samples.We analyzed individual variation in fecal cortisol levels to test the effects of season(i.e., the mating and non-mating seasons) and position in the dominance hierarchy.Our results show that the macaque subjects had higher fecal cortisol levels in the mating season.There was no significant difference in the cortisol levels of high-ranked, middle-ranked, and low-ranked males in the non-mating season, but in the mating season, cortisol levels of middle-ranked males were significantly higher than those of both high- and low-ranked males.As we have known, this is the first study to investigate the cortisol levels in wild Tibetan macaques, and analyze the effects of seasonality and social ranks on cortisol.