Doctoral Dissertation Research: Socioendocrinology of Male Reproductive Strategies in the Siamang (Symphalangus Syndactylus)

这项研究试图阐明影响雄性灵长类动物行为和荷尔蒙特征的进化力量。特别是，它将在一夫一妻制和一夫多妻制交配制度的背景下，探索男性内分泌学与男性-男性竞争、父母努力与女性生殖状态之间的相关性。数据将来自苏门答腊岛(印度尼西亚)的四个一夫一妻制和三个多配偶的暹罗(Hylobatidae：Symphalangus syndactylus)的行为观察和非侵入性激素采样。无生物危害的荷尔蒙提取物将被储存在野外并在美国进行分析。这些数据将揭示灵长类许多引人注目且鲜为人知的方面的共同进化，包括人类、社会和生殖生物学，如性内和性间攻击、配对结合和父亲照顾。这项工作的智力贡献主要分为四个方面：第一，这项研究将提供第一个关于野生一夫一妻制和一夫多妻(非人类)类人猿的荷尔蒙数据。这些交配系统在哺乳动物中非常罕见(约3%)，因此，这些数据对于改进目前的哺乳动物社会进化模型是必不可少的。第二，本研究评估了结对雄性对不同生殖挑战(社会群体内外的性竞争对手)的激素和行为反应。因此，这些数据将检验守护配偶在人类男性竞争中假设的重要作用，并将扩大迄今仅在人类身上测试的理论的广度，如“偷猎配偶”。第三，父亲的照顾是人类行为生物学的一个显著特征，但在灵长类动物中相当特殊。通过提供另一种双亲类人猿的数据，这项研究将使我们第一次能够评估这些人类模式的普遍性，并澄清与男性父母相关的条件和约束。最后，最近的实验数据表明，人类的男性行为受到女性生殖状态的影响(通过视觉或嗅觉线索)。对猿猴类似影响的评估将有助于理解人类和非人类灵长类动物排卵信号与隐藏排卵的起源和功能。这项研究的一个更广泛的影响是对保护工作的贡献：这项研究将增进对暹曼人口和种群动态的了解，并将准确评估栖息地退化和碎片化的影响。该项目将雇用和培训至少5名当地外勤助理。此外，还将支持和监督印度尼西亚大学两名硕士研究生的实地考察工作。当局现正讨论在Way Canguk设立灵长类野外学校的计划，以推动本地的教育/保育工作。结果将透过经同行评审的刊物和参加专业会议而公布。这将有助于指导未来对这群社会一夫一妻制类人猿的近机制(例如，关注其他激素)、心理相关性、分散模式和雌性生殖策略的研究。最后，该项目将为获奖者提供现场内分泌学和实验室程序的广泛实践，并将拓宽他可以教授的学科范围，以及他将为未来工作场所带来的专业知识。

This research seeks to clarify the evolutionary forces shaping the behavioral and hormonal profiles of male primates. In particular, it will explore the correlations between male endocrinology and male-male competition, parental effort and female reproductive state, in the context of monogamous and polyandrous mating systems. Data will come from behavioral observation and non-invasive hormonal sampling of four monogamous and three polyandrous groups of siamangs (Hylobatidae: Symphalangus syndactylus) in Sumatra (Indonesia). Non-biohazardous hormonal extracts will be stored in the field and analyzed in the U.S.These data will shed light on the co-evolution of many striking and poorly understood aspects of primate, including human, social and reproductive biology, such as intra- and intersexual aggression, pair bonding and paternal care. The intellectual contributions of this work fall into four broad areas:First, this study will provide the first hormonal data on a wild monogamous and polyandrous (nonhuman) hominoid. These mating systems are extremely rare among mammals (about 3%), thus, these data are essential for the improvement of current models of mammalian social evolution.Second, this investigation evaluates the hormonal and behavioral responses of pair-bonded males to different reproductive challenges (sexual competitors within or outside the social group). These data will therefore test the hypothetically important role of mate guarding in human male competition, and will expand the breadth of theories so far tested only in humans, such as "mate poaching".Third, paternal care is a conspicuous feature of human behavioral biology, but rather exceptional among primates. By providing data on an additional biparental ape, this study will allow us, for the first time, to assess the generality of these human patterns, and clarify the conditions and constraints associated with male parenting.Finally, recent experimental data shows that human male behavior is affected by female reproductive state (through visual or olfactory cues). An evaluation of similar effects on siamangs will contribute to the understanding of the origin and function of signaling versus concealment of ovulation in human and non-human primates. It will also help determining the social and ecological conditions under which female reproductive status affect male social and reproductive behavior.One broader impact of this research is its contribution to conservation efforts: the study will improve the understanding of siamang demography and population dynamics, and will provide an accurate assessment of the impact of habitat deterioration and fragmentation.The project will employ and train at least five local field assistants. In addition, the fieldwork of two Masters students at the University of Indonesia will be supported and supervised. Plans are being discussed to establish a primatology field school at Way Canguk, to further local education/conservation efforts.Results will be disseminated through peer-reviewed publications and participation in professional meetings. This will help to guide future studies of proximate mechanisms (e.g. focusing on other hormones), psychological correlates, dispersal patterns, and female reproductive strategies in this group of socially monogamous apes.Finally, this project will provide the awardee's with extensive practice with field endocrinology and laboratory procedures, and it will broaden the range of subjects he can offer to teach, as well as the expertise that he will bring to future working places.