The Energy Conservation Hypothesis has been proposed to account for a number of the unusual traits found in the Malagasy primates including: female dominance, male/female body size-monomorphism, and strict synchronized breeding. Energy conservation is thought to be an adaptive complex selected to help lemurs, particularly female lemurs, extract and conserve energy in their seasonally and stochastically resource-poor environments of Madagascar. This project tests the Energy Conservation Hypothesis using ecological, behavioral, nutritional, and endocrinological data collected on wild ring-tailed lemurs (Lemur catta) in the spiny forest habitat at Tsimanampetsotsa National Park (TNP), Madagascar. These data help understand the ways in which male and female ring-tailed lemurs may be constrained by seasonal fluctuations in resource abundance, differential abilities to secure and extract nutrients and calories, and variation in stress responses to seasonality. TNP is an ideal location for this research as it is a large undisturbed spiny forest, and is similar to habitat types to which ring-tailed lemurs are likely adapted. This is the first long-term project examining ring-tailed lemurs in this habitat, and as such, will provide the framework to better understand ring-tailed lemur ecology in all other habitat types. Additionally, this work is broadly applicable to studies of mammalian reproductive costs, niche partitioning within the sexes, and the effect of environment on the interspecific dynamics of resource allocation.
This long-term project seeks to understand how male and female lemurs conserve energy in relation to seasonal differences in food abundances and other factors that cause stress. The broader impacts of this research include promoting science education and broadening participation of underrepresented groups through targeting adolescent girls and Native Americans students, advancement of infrastructure and collaboration through setting up a new research camp at TNP and a biological science laboratory at the Université de Toliara, broad dissemination of knowledge through a digital herbarium of ring-tailed lemur plant foods, and larger benefits to society through promoting conservation of the charismatic flagship ring-tailed lemur and its habitat.
This research examined the ecology of ring-tailed lemurs (Lemur catta) at the Tsimanampetsotsa National Park in southwestern Madagascar. Lemurs have a number of traits which are unusual for primates, or even mammals, such as female dominance. The goal of this project was to examine ring-tailed lemur feeding ecology and test the hypothesis which predicts that female lemurs gain a nutritional advantage over males. We found that female ring-tailed lemurs had a diet that was significantly higher in quality and calories, when compared to that of males. Also, both males and females had insufficient diets during the dry season, when food resources are low. Female dominance may be particularly important during the dry times of year, because in addition to low overall food availability, female lemurs are pregnant and lactating, both of which are metabolically taxing. Interestingly, we also found that these lemurs were regularly awake and active during the night. Cathemerality, which includes both day and night activity periods, is found in some lemur species, but ring-tailed lemurs have been regarded as "strictly diurnal." These data are of interest to other lemur researchers, as they help explain female dominance, and suggest that cathemerality may be a more wide-spread trait than expected. The Co-PI is dedicated to integrating the aforementioned research and discoveries into teaching fostering involvement in students, particularly those from underrepresented groups. Research methods and findings were incorporated into curriculum taught to undergraduate and graduate students at a primate conservation field school in Costa Rica (December 2011- January 2012), which included students of underrepresented groups. The Co-PI also trained two American undergraduate students and one Malagasy graduate student in field methods. The American students both plan to start graduate school in the fall of 2012, and the Malagasy student was provided with necessary supplies and a stipend to pursue further research. Also, the Co-PI is a member of the Diversity Committee and was a reviewer and moderator for a special symposium for underrepresented undergraduate students, at the 2012 meetings of the American Association of Physical Anthropologists. This symposium aimed to foster research interest in a diverse group of students and was highly successful. The Co-PI has disseminated research findings to a larger audience, through presentations at the aforementioned 2012 meetings of the American Association of Physical Anthropologists, but also at the San Diego Zoo Conservation Institute, the San Diego Zoo, and through guest lectures at the University of Colorado Boulder. Furthermore, the Co-PI will hold a symposium at the upcoming 2012 meetings for the International Primatological Society, on methods and usage of camera traps within primatology. Research findings and digital herbaria and osteological collections from field research are available on the Co-PI's website and at the University of Colorado Boulder Natural History Museum. During this research the PI and Co-PI were able enhance infrastructure at the University of Toliara, Madagascar, which is the closest university to Tsimanampetsotsa and the second largest university in Madagascar. Basic features such as electricity and water were connected to the Biology building and laboratories. Also, several used laptop computers were transported from Colorado to Toliara and donated to the Biology department, and training was provided for students unfamiliar with computers. Physical samples of plants and animal bones collected in the field were donated to and are now housed at the University of Toliara, and are utilized by Malagasy and foreign researchers. This award allowed the Co-PI to carry out this exciting and successful research, which formed the basis of her doctoral dissertation. Results will be further disseminated to academic journals, and the Co-PI is well situated to propose and conduct research in the future. The Co-PI is from an underrepresented group herself, and plans to use these data and future research to aid in habitat and lemur conservation, but also to improve the livelihoods of poverty stricken people residing in Madagascar. These data and future research benefit society as a whole through education, conservation, knowledge, and improved welfare.
