Document Type
Thesis
Date of Degree Completion
Spring 2026
Degree Name
Master of Science (MS)
Department
Primate Behavior
Committee Chair
Kara I. Gabriel
Second Committee Member
Jessica Mayhew
Third Committee Member
April Binder
Abstract
In zoos, gorillas are typically housed in family or all-male groups. Continued investigation of factors that mitigate or predict aggression is critical for improving management practices. Captive western lowland gorillas exhibit inconspicuous or subtle social behaviors; therefore, proximity is commonly used as a metric of affiliation between individuals. Following conflict, western lowland gorillas display two forms of post-conflict behaviors (PCBs), reconciliation and consolation. In the current study, it was predicted that mother-offspring dyads would exhibit the strongest proximity relationships, followed by silverback-immature dyads, non-mother female-immature dyads, and female–female dyads. Additionally, dyads with higher proximity were expected to exhibit higher levels of PCBs. Proximity among group members was measured in two western lowland gorilla (Gorilla gorilla gorilla) groups at the Woodland Park Zoo in Seattle, WA, using 10 min instantaneous scans. When conflicts occurred, 30 min focal observations of the victim were conducted to record PCBs. Collected data included a total of 872 (424 and 448 in each group, respectively) proximity scans and behavior during 20 conflicts (14 and 6 in each group, respectively), along with associated PCB observation periods. Females in both groups showed relatively high frequencies of no proximity. Juveniles exhibited high frequencies of close contact proximity with one another and with the resident silverback. In both groups, the dominant female initiated most conflicts. When present, juveniles accounted for the most consolation behaviors following conflict; in their absence, consolation occurred equally in adults, regardless of sex. Reconciliation was observed in both groups, including among females, and did not appear to vary systematically by sex or age class but rather by individual social relationships.
Recommended Citation
Scott, Robyn R., "Proximity Relationships and Post-Conflict Behaviors in Captive Western Lowland Gorillas (Gorilla gorilla gorilla)" (2026). All Master's Theses. 2310.
https://digitalcommons.cwu.edu/etd/2310