Doctoral Dissertation Improvement: An Experimental Analysis of Alarm Calling Behavior in Wild Tufted Capuchin Monkeys (Cebus apella)

在美国国家科学基金会的资助下，查尔斯·詹森博士将进行为期一年的实地考察，调查阿根廷东北部伊瓜苏国家公园簇绒卷尾猴警报呼叫行为的演变。警报呼叫，即被捕食物种在发现捕食者时发出的声音，在许多群居动物中发现。这些叫声一直是进化生物学家的兴趣所在，因为它们的存在似乎与进化理论相矛盾;一个在捕食者面前发出声音的个体比一个沉默的个体更容易被捕食者发现。几个假设，分为三个主要类别，已经提出来解释如何报警电话可以保持在人口。首先，警报可以直接使呼叫者受益（例如，如果警报阻止捕食者攻击呼叫者）。第二，警报可能会使呼叫者的亲属受益，提醒他们捕食者的存在。最后，个体可能能够在没有捕食者的情况下使用叫声来操纵其他群体成员的行为（例如，掠夺粮食资源）。虽然属于这些类别的假设已经在一些鸟类和哺乳动物身上得到了验证，但对灵长类动物警报叫声的研究却很少。这项研究的目的是第一次广泛地测试多种假设的野生灵长类动物之间的报警呼叫的进化，并检查报警呼叫是否被用来篡夺其他组成员的资源。为了检验报警呼叫行为的这些方面，将进行三种类型的实验。首先，将使用卷尾猴的捕食者模型（包括豹猫、鹰和蛇）来确定猴子在发现捕食者时的反应。第二，警报呼叫的录音将被回放给鸟类康复中心的活鹰，以确定警报呼叫的产生是否阻止捕食者攻击呼叫者。第三，将使用悬挂在树枝上并装满香蕉的平台来确定食物的数量和分布是否会影响卷尾猴在没有捕食者的情况下发出警报的倾向。这项研究的智力价值将是更好地理解灵长类动物中允许进化和维持警报呼叫的因素。由于进化生物学家对警报的广泛兴趣以及灵长类物种明显缺乏此类数据，因此该项目将产生的数据非常重要。这项研究的更广泛的影响是，它将增加人们对灵长类动物行为的一个广泛关注但研究不足的方面的了解。此外，该项目将有助于培训灵长类动物行为研究生（合作PI）以及培训东道国的本科生和研究生。阿根廷现场助理将有机会与研究动物一起进行研究，以完成他们的本科论文，共同主要研究者将有机会担任这些项目的论文顾问或共同顾问。最后，在鸟类康复中心进行的实验将为上巴拉那大西洋森林仅存的大型连续片段的保护工作提供急需的资金。

With funding from the National Science Foundation, Dr. Charles Janson will conduct one year of fieldwork to investigate the evolution of alarm calling behavior in tufted capuchin monkeys in Iguazu National Park in northeastern Argentina. Alarm calls, vocalizations given by prey species when a predator is detected, are found in many group-living animals. These calls have long been of interest to evolutionary biologists because their existence seems to contradict evolutionary theory; an individual who produces a vocalization while in the presence of a predator is more likely to be detected by the predator than is a silent individual. Several hypotheses, falling into three main categories, have been put forth to explain how alarm calls can be maintained in a population. First, an alarm may benefit the caller directly (e.g., if alarms deter the predator from attacking the caller). Second, an alarm may benefit relatives of the caller by alerting them to the presence of a predator. Finally, individuals may be able to use the calls in the absence of predators to manipulate the behavior of other group members (e.g., to usurp food resources). Although hypotheses falling into these categories have been tested in a number of birds and mammals, studies of alarm calls among primates are scant. The aim of this study is to be the first to extensively test multiple hypotheses for the evolution of alarm calling among wild primates and to examine whether or not alarm calls are used to usurp resources from other group members. In order to examine theses aspects of alarm calling behavior, three types of experiments will be conducted. First, models of predators of capuchin monkeys (including ocelots, hawk-eagles, and snakes) will be used to determine the reaction of the monkeys upon detecting predators. Second, recordings of alarm calls will be played back to live hawk-eagles in an avian rehabilitation center in order to determine if the production of alarm calls deters the predator from attacking a caller. Third, platforms suspended from tree branches and filled with bananas will be used to determine if the amount and distribution of food affects the propensity of capuchin monkeys to produce alarm calls in the absence of a predator. The intellectual merit of this study will be a better understanding of the factors that allowed for the evolution and maintenance of alarm calls among primates. The data which will result from this project are important because of both the widespread interest in alarm calling among evolutionary biologists and the notable absence of such data for primate species. The broader impacts of the study are that it will increase what is known about a widely noted but under-investigated aspect of primate behavior. In addition, this project will contribute to the training of a graduate student (the co-PI) in primate behavior as well as to the training of undergraduate and post-graduate students from the host country. Argentine field assistants will be given the opportunity to conduct research with the study animals for their undergraduate theses and the co-PI will have the opportunity to serve as the thesis advisor or co-advisor for these projects. Finally, the experiments conducted at the avian rehabilitation center will provide much needed funding for conservation efforts in what is the only remaining large continuous fragment of the Upper Parana Atlantic Forest.