Doctoral Dissertation Research: How primates assess risk while moving in the trees

大多数灵长类动物在树上生活和移动，关于灵长类动物骨骼的形状和它们移动的方式如何使灵长类动物能够在陡峭、薄、分散和弯曲的树枝上行走，有大量的研究。本博士论文研究项目评估了灵长类动物的认知能力如何使这些动物在环境中导航潜在风险时保持安全。这项研究的第一部分分析了灵长类动物在其野生栖息地中移动的视频片段，以评估它们在穿越间隙或在不同高度的树上移动时是否会改变移动方式。这项研究的第二部分研究了白天生活和夜间生活的灵长类动物如何在不同数量的光线可用时收集有关潜在运动支持安全的信息。这项研究的结果帮助我们更好地理解解剖学和决策是如何帮助我们的近亲驾驭环境的。该项目通过为高中生提供短期课程和实习，支持K-12 STEM教育和公共宣传。树木的运动尤其困难，因为支撑是不连续的，大小、方向和顺应性各不相同。之前大多数关于灵长类动物运动适应的研究都采用了一个框架，直接将颅后形态学的变化与运动表现联系起来，以评估灵长类动物是否独特地适合这种具有挑战性的环境。然而，之前的研究在很大程度上绕过了可能影响行为的感觉和认知过程。本项目使用灵长类动物运动生物力学领域的新分析工具来研究灵长类动物如何在树栖环境中评估风险，重点关注三个综合项目来分析灵长类动物在其环境中运动的记录，旨在1)评估灵长类动物在模拟树栖环境中的基线表现，不同光照条件下的表现，以及这些变量如何影响路径选择；2)量化几种不同的非人灵长类动物在决定如何在野外栖息地的不同支撑物上移动时的行为特征。这项研究的结果有助于更好地理解灵长类动物的适应和进化，特别是为在树上移动时保持安全的感觉和认知过程提供了信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Most primate species live and move in trees, and there is a wealth of research on how the shape of primate skeletons and the way they move allows primates to navigate branches that can be steep, thin, spread out, and bend underneath their weight. This doctoral dissertation research project assesses how primate cognition may allow these animals to stay safe while navigating potential risks in their environment. The first part of this research analyzes video footage of primates moving in their wild habitats to assess whether they change way they move when crossing gaps or when moving at different heights in trees. The second part of this research studies how day-living and night-living primates collect information about the safety of potential supports for movement when different amounts of light are available. The results of this research help us better understand how anatomy and decision making help our close relatives navigate their environments. This project supports K-12 STEM education and public outreach through short courses and internships for high school students. Arboreal locomotion is particularly difficult, given that supports are discontinuous and vary in size, orientation, and compliance. Most previous studies on primate locomotor adaptation have adopted a framework that directly connects variation in postcranial morphology with locomotor performance to assess whether primates are uniquely suited to this challenging environment. However, previous work has largely bypassed the sensory and cognitive processes that may also influence behavior. This project uses analytical tools novel to the field of primate locomotor biomechanics to investigate how primates assess risk in arboreal environments, focusing on three integrated projects to analyze recordings of primates moving in their environments, designed to 1) assess baseline performance of primates in simulated arboreal environments, performance under varying light conditions, and how these variables influence path choice, and 2) quantifying behavioral profiles of several different nonhuman primate species as they make decisions on how to move on varied supports in their wild habitats. The results of this research contribute to a better understanding of primate adaptation and evolution, and specifically inform ideas regarding the sensory and cognitive processes that go into maintaining safety while moving in the trees.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.