Doctoral Dissertation Improvement: The Impact of Seasonal Variation in Food Resources and Ranging Patterns on the Reproductive Physiology and Behavior of Female Spider Monkeys

在人类和类人猿身上，已经证明雌性的生殖周期会随着能量平衡的变化而变化。特别是，研究表明，当饮食质量不佳或对持续的体力消耗做出反应时，卵巢类固醇水平(如雌激素和孕激素)会下降，这可能会导致不孕不育。但是，虽然这种模式已经在人类及其近亲身上得到了证明，但所谓的生态能量学假说(Eeh)还没有在任何其他非人类灵长类动物中得到测试。蜘蛛猴提供了一个很好的模型来检验这一假说，因为与许多新大陆猴子相比，它们与类人猿有许多相关的特征，包括非季节性繁殖、延长的繁殖参数和高度的食物专业化。之前对蜘蛛猴的研究表明，雌性蜘蛛猴在成熟果实丰度较低的时候无法怀孕，这是一个一致的模式。然而，到目前为止，还没有研究充分地证明饮食、活动水平和生殖条件之间存在明确的联系。这项研究在巴拿马巴罗科罗拉多岛上自由放养的黑手蜘蛛猴身上测试了这种蜘蛛猴。通过结合雌性蜘蛛猴的觅食行为数据和关于当地水果丰度和营养含量的现有信息来评估饮食质量。然后将这些值与已知雌性的生殖周期的月度变化进行比较。这项研究的结果有助于更好地理解蜘蛛猴的生殖生物学和行为，并提高我们对资源季节性变化如何影响灵长类进化的理解。此外，通过专注于对蜘蛛猴重要的特定果树物种，这项研究有可能为未来的保护管理决策提供信息。最后，这项博士论文研究项目还有助于一名拉美裔女性研究生的专业发展，并将涉及与拉丁美洲研究人员的合作。

In both humans and great apes it has been demonstrated that a female's reproductive cycle varies in response to energy balance. In particular, research has shown that levels of ovarian steroids, such as estrogen and progesterone, fall when diet quality is poor or in response to sustained physical exertion, potentially resulting in infertility. But while this pattern has been documented in humans and their closest relatives, the so-called ecological energetics hypothesis (EEH) has not been tested in any other non-human primate. Spider monkeys provide an excellent model to test this hypothesis because in contrast to many New World monkeys, they share a number of relevant traits with the great apes including non-seasonal breeding, extended reproductive parameters, and a high degree of food specialization. Previous research on spider monkeys has demonstrated a consistent pattern whereby females fail to conceive during times when ripe fruit abundance is low. To date, however, no study has adequately demonstrated a clear link between diet, activity levels, and reproductive condition. This research tests the EEH in free ranging black-handed spider monkeys on Barro Colorado Island, Panama. Diet quality is assessed by combining female spider monkey foraging behavior data with available information on local fruit abundance and nutritional content. These values are then compared to monthly changes in the reproductive cycles of known females. Results from this study contribute to a better understanding of spider monkey reproductive biology and behavior and improve our understanding of how seasonal changes in resources impact primate evolution. Furthermore, by focusing on specific fruiting species important to spider monkeys the research has the potential to inform future conservation management decisions. Finally, this doctoral dissertation research project also contributes to the professional development of a female, Hispanic graduate student and will involve collaboration with Latin American researchers.