Document Type


Date of Degree Completion

Spring 2022

Degree Name

Master of Science (MS)


Primate Behavior

Committee Chair

Kara I. Gabriel

Second Committee Member

J. B. Mulcahy

Third Committee Member

Bonnie King Hendrickson

Fourth Committee Member

Susan D. Lonborg


Environmental enrichment is important for animal welfare because it can promote psychological wellbeing and enable animals to express their natural behaviors in captive settings. Chimpanzees (Pan troglodytes) have unique cognitive abilities and are prone to engaging in abnormal behaviors in unstimulating conditions. Environmental enrichment can meet their need for mental stimulation and prevent the expression of abnormal behaviors in captivity. However, chimpanzees may show individual variability in the way in which they benefit from enrichment and use enrichment devices, so investigating nuances in enrichment use as well as understanding individual differences in enrichment use are important to be better able to meet the enrichment needs of captive chimpanzees. In the current study, a sample from 2,054 videos of captive chimpanzees (P. troglodytes) housed at Chimpanzee Sanctuary Northwest in Cle Elum, WA, using enrichment items was coded using a detailed ethogram to determine if the ethograms were effective in capturing the use of different types of enrichment objects, engagement in manipulation behaviors, and the social contexts surrounding enrichment use. The majority of enrichment object use and manipulation behaviors were accounted for by the ethograms, with “other” designations being rarely used in coding. As predicted, specific enrichment objects correlated with different manipulation behaviors and social contexts, suggesting that enrichment objects can fulfill different behavioral and social needs. Additionally, individual chimpanzees showed unique preferences for enrichment objects, indicating that caregivers of captive chimpanzees should consider individual needs of enrichment rather than using a “one size fits all” approach to enrichment provisions.

Available for download on Sunday, April 25, 2027