Doctoral Dissertation Research: The energetic costs of motherhood in primates

哺乳动物的母亲已经进化到在保持身体健康的同时为婴儿产奶，但野生灵长类动物的母亲如何改变饮食和行为以确保婴儿和母亲的生存，我们知之甚少。这个论文项目研究野生猩猩母亲如何满足他们的能量需求，而在长时间的低水果和整体热量供应喂养婴儿。这项研究将为人类祖先提供一个比较模型，这些祖先也可能在资源不确定的时期幸存下来并繁衍后代。此外，婆罗洲猩猩是极度濒危物种，该项目的研究结果将支持灵长类动物保护工作。该项目还将为STEM领域中代表性不足群体的学生提供数据管理、行为数据收集和基于实验室的行为内分泌学方面的培训。对灵长类动物生殖和生活史的研究表明，灵长类动物的妊娠期和哺乳期较长，相对于其他类似大小的哺乳动物，其幼年依赖性也较长。因此，灵长类动物的母亲，特别是那些在不可预测和食物供应不足的时期进行多年哺乳的母亲，可能已经进化出一套行为和生理适应，以应对母亲长期的能量需求，同时最大限度地减少对发育中的婴儿的风险。本项目研究了野生婆罗洲母猩猩（Pongo pygmaeus wurmbii）在婴儿发育期间维持体内平衡的行为和生理策略。该项目采用了几种非侵入性的方法：猩猩的行为观察、食物的宏量营养素分析和生理尿液分析。这将是首次对野生灵长类物种进行研究，以测试母亲是否会在哺乳和婴儿发育期间调节其营养摄入和随后的能量状态，以及它们是否/如何在这一能量消耗旺盛的时期保持体内平衡。

Mammalian mothers have evolved to produce milk for their infants while maintaining a healthy body condition, but little is known about how wild primate mothers modify their diet and behavior to ensure both infant and mother survival. This dissertation project examines how wild orangutan mothers meet their energetic needs while nursing an infant during extended periods of low fruit and overall caloric availability. The research will provide a comparative model for human ancestors that may also have survived and reproduced through periods of resource uncertainty. In addition, Bornean orangutans are critically endangered, and research findings from this project will support primate conservation efforts. This project will also provide training in data management, behavioral data collection, and lab-based behavioral endocrinology for students from underrepresented groups in the STEM fields.Research focusing on primate reproduction and life-history has revealed that primates have longer gestation and lactation periods, and extended periods of juvenile dependency relative to other mammalian species of similar size. Thus, it is likely that primate mothers, particularly those who nurse for multiple years spanning periods of unpredictable and low food availability, will have evolved a suite of behavioral and physiological adaptions to cope with the long-term energetic demands of motherhood while minimizing risk to her developing infant. This project examines the behavioral and physiological strategies that wild Bornean mother orangutans (Pongo pygmaeus wurmbii) use to maintain homeostasis across periods of infant development. The project utilizes several non-invasive methodologies: behavioral observations of orangutans, macronutrient analysis of food items, and physiological urinary analyses. This will be one of the first studies of a wild primate species to test if mothers modulate their nutritional intake and subsequent energetic status throughout lactation and infant development, and if/how they maintain homeostasis during this energetically costly period.