Food Mechanics, Foraging Behavior, and The Evolution of 'Robust' (Cebus apella) and 'Gracile' (Cebus olivaceus) Capuchin Monkeys in Guyana

该项目的目的是比较圭亚那Iwokrama雨林保护区的簇尾卷尾猴（Cebus apella）和羽尾卷尾猴（Cebus olivaceus）的食物力学和食物加工行为。卷尾猴是一种新世界的猴子，分布在南美洲中部到南部。羊头草属具有两种不同的形态类型；丛状或“健壮”型由一种和三种非丛状或“纤细”型组成，包括本研究感兴趣的物种C. olivaceus。绒毛型以其更“健壮”和强大的咀嚼系统而闻名。然而，人们对每个物种所吃食物的机械特性差异以及这些差异与卷尾猴解剖结构的关系知之甚少。本研究的主要目的是收集物种在食物制备和加工模式（手工和口服）方面的行为差异数据，以及它们摄入的食物物理特性的详细季节性数据。对现存卷尾猴“健壮”和“纤细”物种之间生态形态学差异的研究提供了一个独特的机会，可以测试其他“健壮”和“纤细”灵长类动物（如人类祖先中已灭绝的灵长类动物）的喂养生态学变异性问题。这不仅是因为它们与早期类人祖先在咀嚼方面有相似之处，还因为它们与类人猿和现代人有着广泛的共同特征，比如婴儿期发育缓慢，在各种情况下使用工具，以及除了人类之外灵长类动物中相对最大的大脑大小。此外，近十年来，灵长类动物咀嚼系统与食物力学特性之间的关系也引起了越来越多的关注。关于咀嚼形态的差异以及果实和种子的机械特性的数据，为了解物种在解剖学和摄食生态学上的差异提供了关键的见解。该项目将通过识别更多的食品机械分类，并将这些分类与同类灵长类物种之间更微妙的形态差异联系起来，从而增加这方面的知识。

The goal of this project is to compare the food mechanics, and food processing behavior of tufted capuchins (Cebus apella) and weeper capuchins (Cebus olivaceus) at the Iwokrama Rainforest Reserve, Guyana. Capuchins are New World monkeys ranging from Central to southern South America. The genus Cebus exhibits two distinct morphological types; the tufted or "robust" type consisting of a single species and three species of untufted or "gracile" types, including C. olivaceus, the species of interest to this study. The tufted type is noted for its more "robust" and powerful masticatory system. However, little is known regarding differences in the mechanical properties of foods eaten by each species and how such differences relate to capuchin anatomy. The main objectives of this study are to collect behavioral data on species differences in patterns of food preparation and processing (manual and oral), and detailed seasonal data on the physical properties of the foods they ingest. The study of ecomorphological distinctions between "robust" and "gracile" species of extant capuchin offers a unique opportunity to test questions concerning variability in the feeding ecology of other "robust" and "gracile" primates such as extinct primates in human ancestry. This is due not only to the masticatory similarities they share with early human-like ancestors, but also to the broad set of features they share with great apes and modern humans, such as slow infant development, tool-use in various contexts, and the largest relative brain size of any primate except humans. In addition, research concerning the relationship between the mechanical properties of foods and the masticatory systems of primates has seen growing interest over the last decade. Data on differences in masticatory morphology and on the mechanical properties of available fruits and seeds have provided critical insight into species-specific differences in anatomy and feeding ecology. This project will add to this knowledge by identifying more discrete mechanical categories for foods, and by relating these categories to more subtle morphological differences between congeneric primate species.