Managing the socialization of an adult male gorilla (Gorilla gorilla gorilla) with a history of social deprivation

Abstract

Most non-human primates exhibit aggression during changes in social group composition. In zoological parks, group membership changes are necessary for optimal population management, but can elicit problematic aggression. Furthermore, some primates with a long history of social deprivation are hyperaggressive when introduced to conspecifics. In this study of one male gorilla with a 30-year history of social deprivation, we assessed the rate of aggression quantitatively during a four-step socialization procedure. We hypothesized that 1) the frequency of agonistic/display behaviors would increase markedly at the beginning of each phase of the socialization, then decline to baseline levels over time in each phase and 2) the frequency of affiliative behaviors would not vary systematically within or between phases of socialization. Our results largely supported these predictions, and we found the four-step socialization process effective in managing aggression in this case. In addition to documenting the successful socialization of a socially deprived adult male gorilla, we believe that the empirical process used in this case argues for scientific management of other introductions. Zoo

Comparison of two introduction methods for African elephants (Loxodonta africana)

“…Given the contribution of agonistic behavior categories (including active and passive aggression) to general behavior patterns, the results suggest that the sequential method of introduction did effectively manage aggression during these introductions. These findings closely match those described by Burks et al [2001], and suggest that the general patterns observed are likely to be found in other applications of the sequential introduction method.…”

“…Therefore, a modified version of the methodology described by Burks et al [2001] appeared appropriate for use in investigating two approaches to introductions in this species. One method involved decision-making based primarily on intuitive assessments by animal managers, while the other method rigorously and systematically followed the introduction steps as outlined in the protocol.…”

Behavioral effects of introducing pied tamarin (Saguinus bicolor) to black howler monkey (Alouatta caraya) and white‐faced saki (Pithecia pithecia) in a zoological park

“…Past observations of intra-specific introductions have shown that at each stage, aggression among individuals will generally increase at first but then return to a pre-introduction baseline [Burks et al, 1998[Burks et al, , 2001. Thus, we expected to observe this pattern of aggression here, although it had not been previously documented in an interspecific introduction.…”

Effects of an Increase in Group Size on the Social Behavior of a Group of Rough-Toothed Dolphins (Steno bredanensis)

“…Captive facilities sometimes find it necessary to add or remove an animal from the social group (Burks et al, 2001). These animal movements are similar to a fission-fusion society in the wild, albeit involuntary in captivity.…”

“…The death or removal of a close associate, change in the dominance hierarchy, or the introduction of a new individual are all likely to affect the social behavior of small groups more so than larger groups. Additionally, changes in social behavior may be more pronounced in captivity than in the wild (Burks et al, 2001). In a study of pigtail monkeys (Macaca nemestrina, Erwin & Erwin, 1976), an increase in group size resulted in an increased frequency of aggressive behaviors.…”