An Analysis of the Correlation between Cortisol Levels and Anxious Behavior of Captive Aye-Ayes (Daubentonia madagscariensis) at the Duke Lemur Center

I sought to determine if there existed a correlation between anxious behavior and cortisol levels for captive Aye-Ayes. I measured stress-related behavior by using an ethnographic methodology and focused on five specific behavior patterns: pacing, self-grooming, vigilance, human interaction, and vocalizations. I conducted 10 hours of observations on eight Aye-Aye individuals for a total of 80 hours. These observations were split between direct observations in an Aye-Aye’s enclosure and indirect observations by videotaping. Saliva samples were collected from each individual using chewed-on swabs; swabs were centrifuged and frozen for later extraction of cortisol concentrations. There was a general increase in anxious behavior when the Aye-Ayes were being observed directly; pacing showed the greatest difference. There was also a slight increase in cortisol concentrations when comparing weeks with direct and indirect observations. This study demonstrated that there is a potential relationship between anxious behavior and cortisol levels in Aye-Ayes that could be better understood with more research. Future studies should conduct more observation hours that are equally split between male and female Aye-Ayes. In addition, saliva samples should be consistently collected immediately after each observation. Finally, cortisol levels from saliva samples should be bolstered with other collection methods, specifically serum and fecal.