Suspensory Postures and Feeding in Varecia Lemurs

With help from the Dean’s Summer Research Fellowship, I was able to spend the summer working at the Duke Lemur Center (DLC) studying ruffed lemurs (Varecia spp.). I have worked at the DLC as a technician assistant and docent since 2018, but my academic interests in animal behavior and ecology motivated me to pursue research at this facility. My project focused on lemur behavior-- specifically, how we can use environmental enrichment to encourage the lemurs to use the natural behaviors they would use in the wild, while still in captivity. We constructed a lattice to hang from the ceiling of their enclosures, where buckets containing high quality food items would subsequently hang from the lattice. In order to get their food, the lemurs would have to use suspensory postures (hanging by some combination of their hands and feet), or they could choose to eat the less preferable, lower quality food that was easily accessible nearby. Varecia readily utilize these suspensory postures in the wild, as their rainforest habitat requires suspension in order to reach the high-quality fruits scattered throughout the trees, yet have far fewer opportunities to do so in their enclosures at the DLC. Thus, this test uses conservation-centered enrichment to encourage natural postures, while generally examining whether Varecia will work for their food. This latter aspect has been a recent topic of interest in the field of animal behavior, with many researchers noticing that animals have a preference to work for their food rather than eating the food that is easily attainable. Indeed, we saw that the lemurs had a preference to work for their food, even when we controlled for dietary quality of the food on the lattice. Not only did they prefer to work for their food, but they readily utilized suspensory postures to do so. These results suggest that our lattice device was effective at encouraging natural postures and demonstrating this “work for food” hypothesis in Varecia spp. From this project, I have been inspired to conduct further research projects with lemurs and will hopefully be doing a follow-up study to this initial project in the spring semester. I hope to work with non-human primates again in the future, and, in general, feel that this experience was crucial in encouraging my passion for research and building my interest in pursuing research as a career. I feel far more confident in my ability to design and implement an original research project, thanks to the support I received from my DLC mentors and the URS office. Please see the pictures below to get a sense of my project’s design and enjoy some lemur content.