Ecological Mechanisms Underlying Differences in Agonistic behavior Among Females in Two Cercopithecine Primate Species

本研究项目将阐明生态机制，最终负责vervet猴（Cercopithecus aethiops）和patas猴（Erythrocebus patas）之间的差异，在组内的女性竞争关系。 尽管同域性和亲缘关系密切，长尾小尾蛾和绿胸小尾蛾在表达雌性竞争关系方面有所不同：雌性长尾小尾蛾具有稳定的线性优势等级，而雌性绿胸小尾蛾具有不太稳定的非线性优势等级。 尽管理论和经验证据表明，这些行为差异最终可以用食物资源的某些质量差异来解释，但我们仍然无法找到导致灵长类动物雌性竞争行为变化的食物的关键特征。 食物的空间分布一直是最重要的特征。 然而，最近对这一群体的研究表明，关键的特征实际上是觅食地点的耗尽时间，这是由食物的大小和处理时间决定的。 虽然海芋的食物比黑尾鼠的食物间隔更宽，但它们的消耗时间也更短。 更有启发性的是，当黑尾长尾雉饲料在两个相邻的栖息地，他们吃的食物，没有不同的空间分布，但不同的耗尽时间，和竞争的相互作用更频繁地发生在栖息地的食物具有较长的耗尽时间。 消耗缓慢的食物可能比消耗迅速的食物更容易被篡夺。 本计画将探讨觅食地点消耗时间与食物间距离在决定黑尾羚与绿胸羚雌性竞争关系差异上的角色。 通过一系列田间试验，系统地控制摄食位点耗竭时间和食物间距离，以确定长尾小蠹和斑胸蛙篡夺的时空阈值水平。 然后将实验中获得的可篡夺性阈值与野生食物的食物间距离和耗尽时间进行比较，以评估阈值是否可以预测自然条件下食物的竞争行为。

This research project will elucidate the ecological mechanisms that are ultimately responsible for differences between vervet monkeys (Cercopithecus aethiops) and patas monkeys (Erythrocebus patas) in female agonistic relationships within groups. Despite their sympatry and phylogenetically close relationship, vervets and patas differ in their expression of female competitive relationships: female vervets have stable, linear dominance hierarchies whereas female patas have less stable, non-linear dominance hierarchies. Although theoretical and empirical evidence suggests that these behavioral differences can be explained ultimately by differences in some quality of food resources, the critical characteristic of food that is responsible for variation in female competitive behavior in primates still eludes us. Spatial distribution of foods has long been the leading contender as the critical characteristic. Recent research on this population of vervets and patas suggests, however, that the critical characteristic is actually feeding site depletion time, which is determined by food size and handling time. Although the foods of patas are more widely spaced than the foods of vervets, they also have shorter depletion times. More revealing is that when vervets forage in two adjacent habitats, they eat foods that do not differ in their spatial distribution but that do differ in their depletion times, and agonistic interactions occur more frequently in the habitat with foods having the longer depletion times. Foods that are depleted slowly may be easier to usurp than foods that are depleted quickly. This project will clarify the roles of feeding site depletion time and interfood distance in determining the differences between vervets and patas in female agonistic relationships. Feeding site depletion time and interfood distance will be systematically manipulated in a series of field experiments to determine the temporal and spatial threshold levels of usurpability for vervets and patas. The thresholds of usurpability obtained in the experiments will then be compared to interfood distances and depletion times of wild foods to assess whether the thresholds can predict agonistic behavior over foods under natural conditions.