DISSERTATION RESEARCH: Enforcement of cooperation in vampire bats

社会合作可能会被免费利用和侵蚀，这种情况发生在一些人从他人那里获得帮助，而自己不承担任何费用。自然选择预计将有利于以防止这种掠夺的方式进行合作的社会有机体。最常见的是，利他主义的特征不会被白吃和自我延续，因为它们有助于亲属，而亲属也继承和传承同样的利他主义特征。对于非亲属之间的合作，生物可能会通过增加对产生回报的伙伴关系的投资，而减少对效益较低的伙伴关系的投资，来防止搭便车。这个项目使用普通吸血蝙蝠之间的食物共享作为合作系统的模型，来测试是否以及如何防止吃白食。雌性吸血蝙蝠会自愿地反胃自己的部分食物，以喂养饥饿的室友。这种看似利他主义的行为发生在相关和不相关的个人之间，是可以诱导的，并且可以在受控环境下进行测量，而不需要培训。蝙蝠会接受和拒绝一个群体内分享食物的伙伴，这提供了一种测试遗传相似性、熟悉度和互惠性对合作决定的影响的方法。通过对圈养动物的一系列实验，这个项目将解决关于吸血蝙蝠如何加强社会合作的三个问题。首先，吸血蝙蝠可以通过发声区分亲缘关系和非亲缘关系吗？其次，吸血蝙蝠会通过优先帮助回报更多的伴侣来施加社会伴侣选择吗？第三，在没有伴侣选择的情况下，吸血蝙蝠是否会通过减少对随着时间推移回报较少的伴侣的投资来施加社会伴侣控制？该项目将培训本科生和研究生，并支持几项外联活动，包括在学术和公共论坛上发表演讲。研究非人类动物中潜在的合作机制，有可能为人类社会行为的起源提供新的见解。

Social cooperation can be exploited and eroded by freeloading, which occurs when some individuals receive help from others at no expense to themselves. Natural selection is expected to favor social organisms that cooperate in ways that prevent such freeloading. Most commonly, altruistic traits become protected from freeloading and self-perpetuating because they help relatives, who also inherit and pass along those same altruistic traits. For cooperation between non-relatives, organisms can potentially prevent freeloading by increasing investment in partnerships that yield returns while decreasing investment in partnerships that are less beneficial. This project uses food sharing in common vampire bats as a model cooperation system to test if and how freeloading is prevented. Female vampire bats will voluntarily regurgitate portions of their own meals to feed hungry roost-mates. This seemingly altruistic behavior occurs among related and nonrelated individuals, is inducible, and is measurable under controlled settings without training. Bats will accept and reject food-sharing partners within a group, which provides a way to test the effects of genetic similarity, familiarity, and reciprocity on cooperative decisions. Through a series of experiments on captive animals this project will address three questions about how vampire bats enforce social cooperation. First, can vampire bats discriminate kin from non-kin using vocalizations? Second, will vampire bats exert social partner choice by preferentially helping partners that reciprocated more than others? Third, in the absence of partner choice, will vampire bats exert social partner control by reducing investments in partners that reciprocate less over time? The project will train undergraduate and graduate students and support several outreach activities, including presentations at academic and public forums. Studying the mechanisms underlying cooperation in nonhuman animals has potential to provide new insight into the origins of human social behavior.