Notes from North Carolina

I recently spent a month in North Carolina – my first visit to the South – where I have been conducting an experimental feeding study on ruffed lemurs (Varecia spp.) at the Duke Lemur Center. The purpose of this study is to validate urinary C-peptide (UCP) as biomarker for insulin and, by extension, a measure of energy balance in lemurs. UCP has been validated in the other major primate clades, but not yet PMEL’s beloved lemurs. So, I spent four weeks collecting daily urine samples from three black-and-white and two red ruffed lemurs.

During the first week my subjects were fed their normal diets, during the second and third weeks they were fed a 30% calorie-restricted diet, then in the fourth week they were returned to their normal diet. The purpose of this dietary restriction was to temporarily reduce their energy balance—the balance between energy intake and energy expenditure—in response to reduced calorie intake. This will allow me to validate that the UCP measures are biologically meaningful, and are true reflections of energy in lemurs.

Over the next couple of months, I will be working in Dr. James Higham’s Primate Hormones and Behavior Lab at NYU to analyze these samples. I will be using enzyme-linked immunosorbent assays (ELISAs) to measure C-peptide levels in the urine and determine whether these levels vary as biologically expected (higher during normal diet weeks and lower during restricted diet weeks). If this validation is successful, we should then be able to measure UCP in wild lemurs and determine the ecological drivers of variation in energetic condition, as well as look at the relationships between energy balance and other behavioral and/or physiological variables as part of our ongoing research pro

Stay tuned for updates!