ABS 2022
Does the Absence of a Silverback Increase Aggression Frequency Amongst Female Gorillas?
Joseph Scinta, Katie Broikos, Jacob Botticelli, Susan Margulis. Canisius College, Buffalo, New York, United States

The silverback, being the primary source of intervention for both internal and external threats to the health and cohesion of the troop, is predicted to have a significant effect on the social behaviors of the other members by his mere presence. We have conducted observational research on the gorillas at the Buffalo Zoo. During a period of time when the silverback was separated from the troop, we examined the frequency of aggressive behavior amongst the adult females in the group. We predict that the frequency of aggressive behavior will increase as a result of the silverback’s absence. We compared behavior during periods ranging from 3 weeks to 3 months when the silverback was absent to comparable periods when he was present. We found that female-female aggression was higher when the silverback was absent (X2=5.33, df=1, P< 0.05). The frequency of aggression declined over time while the silverback was absent, with aggression returning to baseline levels within a month. Our observations suggest that, although the male intervened in aggressive episodes rarely, his presence in the group was a stabilizing factor. The absence of this stabilization led to higher levels of aggression.