Document Type


Date of Degree Completion

Spring 2023

Degree Name

Master of Science (MS)


Primate Behavior

Committee Chair

Kara Gabriel

Second Committee Member

April Binder

Third Committee Member

Lydia Hopper


Thermal imaging, as a tool in psychological research, has been used to distinguish mental states evoked by different environmental and social cues, with prior research across several species. Ambient temperature can affect the precision of the measures of body temperature, however, so we investigated a methodology for recording thermal imaging data in sanctuary-housed chimpanzees (Pan troglodytes) while they engaged in resting behavior across different ambient temperatures. Data were collected on 30 adult chimpanzees (16 females and 14 males) ranging in age from 21 to 53 years (Mage = 33.4 years, SD = 8.0). The chimpanzees lived in nine social groups at Chimp Haven, Louisiana, USA, with 5 to 20 individuals per group (Mgroup size = 12.4, SD = 5.3). The chimpanzees were categorized by age and sex to ensure that sex was balanced between chimpanzees of different ages. Thermal photos were captured after the chimpanzees had been at rest for two minutes. In total, we collected 545 thermal images (M = 18.2 photographs per chimpanzee, SD = 3.4). The mean nasal temperature was positively correlated with ambient temperature (ρ(543) = .52, p < .001), but was not affected by sex and minimally by age. This highlights the importance of measuring, and controlling for, ambient temperature when running studies using nasal temperature change as a tool for measuring mental states in chimpanzees in uncontrolled environments.

Available for download on Saturday, June 07, 2025