Doctoral Dissertation Improvement: Functions and Consequences of Intergroup Aggression in Tufted Capuchin Monkeys

目前灵长类动物行为进化的模型表明，群体间竞争的强度强烈影响灵长类动物社会性的基本方面，包括女性与女性和男性与女性的社会关系。虽然在许多物种中发现了群体之间的相遇，并且通常被描述为具有侵略性，但这些相互作用的功能和后果仍然知之甚少。在群体之间的遭遇战中，攻击性行为被认为有助于捍卫有限的资源或交配机会。本研究将系统地探讨这些可能的功能群体间的侵略在簇绒卷尾猴（Cebus apella）在伊瓜苏国家公园，阿根廷。研究人员将同时跟踪多个社会群体，并记录个体参与群体间接触的模式，群体间攻击的整体强度，以及可能影响这些相互作用的几个因素，包括发情期女性和脆弱婴儿的存在或接近稳定的食物资源。此外，研究人员还将结合生态和行为数据，测试更具侵略性的成功群体是否能够获得或保留重叠地区更优质的领土和资源。群体之间的遭遇战和优势地位所造成的食物损失或获得，将与群体内成员之间的攻击所造成的类似后果进行比较。 为了对特定的假设进行控制测试，研究人员将通过声音播放实验来模拟另一个社会群体的存在。 这些实验将在人工控制的资源附近进行，以独立地操纵明显遭遇的社会和生态背景。以前对非人类灵长类动物群间攻击的研究一直无法收集详细的行为和生态数据，这些数据是区分群间攻击的各种假设功能所必需的。 这个研究项目将通过系统地研究竞争配偶和关键食物资源的重要性来解决这些差距。这项研究还将被用来与以前研究的秘鲁人口，表现出减少群体间的侵略，从而允许直接检查的影响，人口差异的资源分配和可用性对群体间的竞争。 该项目将为阿根廷学生、瓜拉尼社区成员以及可能的美国大学生志愿者提供就业和培训。

Current models of the evolution of primate behavior suggest that the strength of between-group competition strongly affects fundamental aspects of primate sociality, including female-female and male-female social relationships. Although encounters between groups are found in many species and are often described as aggressive, the functions and consequences of these interactions remain poorly understood. Aggressive behavior during encounters between groups is thought to help defend access to limiting resources or mating opportunities. This study will systematically examine these possible functions of between-group aggression in tufted capuchin monkeys (Cebus apella) at Iguazu National Park, Argentina. The researchers will follow multiple social groups simultaneously and record patterns of individual participation in intergroup encounters, the overall intensity of intergroup aggression, and several factors that may affect these interactions, including the presence of estrous females and vulnerable infants or the proximity to contestable food resources. In addition, the researchers will test if more aggressively successful groups gain or retain access to better quality territories and resources in areas of overlap, using a combination of ecological and behavioral data. The loss or gain of food from encounters and dominance between groups will be compared to similar consequences of aggression among members within a group. To make controlled tests of particular hypotheses, the researchers will simulate the presence of another social group with vocal playback experiments. These experiments will occur near artificially-controlled resources to independently manipulate the social and ecological context of apparent encounters.Previous studies of intergroup aggression in non-human primates have been unable to collect the detailed behavioral and ecological data necessary to distinguish among all the various hypothesized functions of between-group aggression. This research project will address these gaps by systematically examining the importance of competition for mates and critical food resources. The study will also be used to compare with previously studied Peruvian populations that exhibit reduced intergroup aggression, thereby allowing direct examination of the influence of population differences in resource distribution and availability on between-group competition. The project will provide employment and training for Argentine students, members of the Guarani community, and possibly U.S. undergraduate volunteers.