Abstract:
For males of gregarious species, dominance status and the strength of affiliative relationships can have major fitness consequences. Social dynamics also impose costs by affecting glucocorticoids, mediators of homeostasis and indicators of the physiological response to challenges and within-group competition. We investigated the relationships between dominance, social bonds, seasonal challenges, and faecal glucocorticoid metabolite (fGC) measures in wild Assamese macaques (Macaca assamensis) at Phu Khieo Wildlife Sanctuary, Thailand, combining behavioural data with 4129 samples from 62 adult males over 15 years. Our previous work on this population suggested that increased competition during the mating season was associated with elevated fGC levels and that, unusually for male primates, lower rank position correlated with higher fGC levels. With a much larger dataset and dynamic measures of sociality, we re-examined these relationships and additionally tested the potentially fGC-attenuating effect of social support. Contrary to our previous study, yet consistent with the majority of work on male primates, dominance rank had a positive relationship with fGC levels, as high status correlated with elevated glucocorticoid measures. fGC levels were increased at the onset of the mating season. We demonstrated an fGC-reducing effect of supportive relationships in males and showed that dynamics in affiliation can correlate with dynamics in physiological responses. Our results suggest that in a system with intermediate contest potential, high dominance status can impose physiological costs on males that may potentially be moderated by social relationships. We highlight the need to consider the dynamics of sociality and competition that influence hormonal processes.
摘要:
对于群居物种的雄性,优势地位和隶属关系的强度可能会产生重大的健身后果。社会动态也会通过影响糖皮质激素来增加成本,体内平衡的中介和对挑战和组内竞争的生理反应的指标。我们调查了优势之间的关系,社会纽带,季节性挑战,PhuKhieo野生动物保护区野生阿萨姆猕猴(Macacaassamensis)的粪便糖皮质激素代谢产物(fGC)测量,泰国,将行为数据与来自62名15岁以上成年男性的4129份样本相结合。我们先前对该种群的研究表明,在交配季节竞争加剧与fGC水平升高有关,对雄性灵长类动物来说是不寻常的,较低的等级位置与较高的fGC水平相关。有了更大的数据集和社会性的动态测量,我们重新检验了这些关系,并额外检验了社会支持的潜在fGC衰减效应.与我们之前的研究相反,但与大多数关于雄性灵长类动物的工作一致,优势等级与fGC水平呈正相关,高状态与糖皮质激素措施升高相关。在交配季节开始时,fGC水平增加。我们证明了男性支持关系的fGC减少作用,并表明隶属关系的动态可以与生理反应的动态相关。我们的结果表明,在具有中等竞赛潜力的系统中,高优势地位会给男性带来生理成本,而这种成本可能会受到社会关系的影响。我们强调需要考虑影响荷尔蒙过程的社会性和竞争的动态。