Leinfelder I, de Vries H, Deleu R, Nelissen M
University of Antwerp, RUCA, Behavioural Biology, Antwerp, Belgium.
Am J Primatol. 2001 Sep;55(1):25-42. doi: 10.1002/ajp.1036.
In a mixed-sex, captive group of hamadryas baboons (Papio hamadryas hamadryas) we investigated whether female grooming relationships are affected by their dominance ranks. Seyfarth's [1977] grooming for support model and Barrett et al.'s [1999] biological market model both predict that in primate groups where competition for monopolizable resources is high, grooming among females is based, at least partly, on the interchange of grooming for rank-related benefits, and that rank thus influences the distribution of grooming in females. Contrary to this prediction, our results show that despite the existence of a linear dominance hierarchy, rather strict dominance relationships, and high food-related aggression rates, grooming among female hamadryas baboons is not affected by rank and is only exchanged for itself. This is understandable since rank differences in our study group only result in differential access to limited, preferred food items that are not actively shared. Although some females are more likely to tolerate one another at the food pile, this tolerance is not determined by their grooming efforts and interchange of grooming for rank-related benefits does not occur. We conclude that female hamadryas baboons groom others in order to be groomed by them, which is supported by our observation that grooming reciprocity within a dyad increases when more grooming occurs in this dyad. Our results indicate that grooming is indeed a valuable commodity in itself, probably because of its stress- and tension-reducing effect. Based on our findings, the existing groom trade model is extended to include circumstances in which monopolizable resources are available but are not traded for grooming.
在一群圈养的阿拉伯狒狒（Papio hamadryas hamadryas）中，我们研究了雌性之间的梳理毛发关系是否会受到其等级地位的影响。塞法思（Seyfarth，1977）的“为获得支持而进行梳理毛发”模型以及巴雷特等人（Barrett et al.，1999）的“生物市场”模型均预测，在对可垄断资源竞争激烈的灵长类群体中，雌性之间的梳理毛发行为至少部分基于为获取与等级相关的利益而进行的梳理毛发交换，因此等级会影响雌性之间梳理毛发行为的分布。与这一预测相反，我们的研究结果表明，尽管存在线性的等级制度、相当严格的等级关系以及与食物相关且发生率较高的攻击行为，但阿拉伯狒狒雌性之间的梳理毛发行为不受等级影响，且只是为了梳理毛发本身而进行交换。这是可以理解的，因为在我们的研究群体中，等级差异仅导致获取有限的、偏好的食物项目的机会不同，而这些食物并不会被主动分享。尽管有些雌性在食物堆处更有可能相互容忍，但这种容忍并非由它们的梳理毛发行为决定，且不存在为获取与等级相关的利益而进行的梳理毛发交换。我们得出结论，阿拉伯狒狒雌性为其他个体梳理毛发是为了让对方也为自己梳理毛发，我们观察到当二元组内的梳理毛发行为增多时，二元组内的梳理毛发互惠行为也会增加，这一结论得到了该观察结果的支持。我们的研究结果表明，梳理毛发本身确实是一种有价值的“商品”，可能是因为它具有减轻压力和缓解紧张的作用。基于我们的研究发现，现有的梳理毛发交易模型得到扩展，以纳入存在可垄断资源但这些资源不会用于交换梳理毛发行为的情况。
