Doctoral Dissertation Improvement: Development of Efficient Foraging Behavior in Aye-Ayes

Duke University, Durham NC

Investigators

Abstract

This project will investigate the factors that limit the development of efficient tap-foraging skills in immature aye-ayes (Daubentonia madagascariensis) at the Duke University Primate Center (DUPC). Using experimental methods, this study will assess the age at which adult-level foraging proficiency is reached, and will determine whether lack of experience, small body size, and/or poor neuromuscular control prevent young aye-ayes from foraging efficiently. Results will test whether the time needed to learn complex foraging skills can explain the remarkably slow development of the aye-aye. Study of the ontogeny of lemur foraging efficiency has important implications for understanding the evolution of slow development, or slow life history, in other primates, including humans. Human life history features, including a long juvenile period and lifespan, may be explained by a dietary shift towards more specialized, hard-to-obtain foods (e.g. meat, larvae). Additionally, human behaviors, such as food sharing with offspring, can be associated with slow life history. Recently, anthropologists have begun to test this hypothesis with long-term data from hunter-gatherer groups, with specific attention to the relative importance of experience and size to foraging efficiency. Following in this vein, the proposed project will be among the first to experimentally test hypotheses for life history evolution. Because aye-ayes, like humans, are also characterized by a relatively slow life history and a specialized, nutrient-rich diet, this study is directly relevant to our understanding of derived human life history traits. More broadly, this research project will provide multiple opportunities for promoting education and participation in research. Preliminary data have been collected with the help of three student research assistants trained in behavioral observations and data collection techniques using hand-held computers. The proposed research will continue to provide opportunities for education and training of student research assistants. Additionally, the DUPC is an educational facility that provides information about lemurs and their ecosystems to thousands of visitors annually. Visitors to the center will have the opportunity to observe data collection sessions and to learn about this research project via educational materials. This research is also more broadly applicable to understanding human dietary development. Like non-human primates and other mammals, humans have been observed to learn about food socially. Eating patterns, including obesity and dieting, appear to develop gradually throughout childhood. Understanding the development of foraging behaviors in non-human primates can help us understand the underlying stages of human dietary development, and may provide insight into preventative treatment of food-related disorders. Finally, this research will provide helpful information for the reintroduction of aye-ayes and other mammals into the wild, and thus has important implications for conservation. While the release of animals within their current or former range is becoming increasingly important in conservation and wildlife management, primates in particular appear to rehabilitate less successfully than other mammals. Discerning how primates learn to forage will help us predict at what age young animals reach foraging proficiency adequate for independent survival, and whether reintroduced animals will be able to forage in a novel environment. This is particularly relevant for the aye-aye, which is highly threatened by habitat loss and hunting.