Behavioral Thermoregulation in Lemurs: The Role of 3D Use of the Forest (2012)

Undergraduate: Jozeph Pendleton

Faculty Advisor: Leslie Digby and Rachel Noble
Department: Environmental Science

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The thermoregulatory sunning behaviors of ringtailed lemurs (Lemur catta) are well known, but habitat use is also a significant means of maintaining body temperature and conserving energy. In this project, a 3D data collection system was created to document spatial thermoregulation in ringtailed lemurs. A group of six adults and three infants was tracked in one of the Duke Lemur Center’s natural habitat enclosures during the summer and fall to create habitat-scale images of the lemurs’ movement. Randomly chosen focal animals were followed for 30-minute periods in the 1.42 hectare enclosure of southeastern semi-deciduous forest and underbrush. GPS readings, observed height, and ambient (from a weather meter) and point temperature measurements (from an infrared thermometer) were taken at 5-minute intervals and combined in 3D scatter plots produced in MATLAB. Concentrations of data points correlated with temperature variation in the habitat, providing evidence of the lemurs’ responses to large-scale temperature differences. When ambient temperatures were below their optimal range, the lemurs tended to move over more territory and spend more time in trees; when temperatures were above optimal, they moved less and spent more time on the ground. Lemurs also chose areas that contrasted with ambient temperature—sitting, for example, in warm areas when it was cold. These findings suggest that ringtailed lemurs adjust their spatial use of the forest as a means of thermoregulation.