Doctoral Dissertation Research: The energetic costs of motherhood in primates

哺乳动物的母亲已经进化到为她们的婴儿生产牛奶，同时保持健康的身体状况，但人们对野生灵长类母亲如何改变饮食和行为以确保婴儿和母亲的生存知之甚少。这篇论文研究了野生猩猩母亲在长期低水果和总热量供应的情况下，如何在哺育婴儿的同时满足她们的能量需求。这项研究将为人类祖先提供一个比较模型，这些祖先可能也在资源不确定时期幸存下来并繁衍了后代。此外，婆罗洲猩猩是极度濒危的物种，该项目的研究结果将支持灵长类动物的保护努力。该项目还将为STEM领域中代表性不足的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。专注于灵长类繁殖和生活史的研究表明，与其他体型相似的哺乳动物物种相比，灵长类有更长的妊娠期和哺乳期，以及更长的幼年依赖期。因此，灵长类母亲，特别是那些在不可预测和低食物供应时期哺乳多年的灵长类母亲，很可能已经进化出一套行为和生理适应，以应对作为母亲的长期精力需求，同时将对其发育中的婴儿的风险降至最低。这个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所使用的行为和生理策略。该项目使用了几种非侵入性的方法：对猩猩的行为观察，对食物的大量营养素分析，以及生理尿液分析。这将是第一次对野生灵长类物种进行研究，以测试母亲是否在整个哺乳期和婴儿发育期间调节她们的营养摄入量和随后的能量状态，以及她们是否/如何在这段耗费能量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.