Group compositional changes impact the social and feeding behaviors of captive hamadryas baboons (Papio hamadryas hamadryas)

Abstract

The formation and modification of social groups in captivity are delicate management tasks. The ability for personnel to anticipate changes in group dynamics following compositional changes can increase the likelihood of successful management with minimized injury or social instability. Hamadryas baboons (Papio hamadryas hamadryas) have a distinctive multi-level social system comprising of one-male units (OMUs) that can make it difficult to apply knowledge from other primates' multi-female/multi-male social structure to changes imposed onto captive hamadryas baboon groups. We conducted an observational study of the behavioral impacts following the introduction of two females into the group of hamadryas baboons at the Wildlife Conservation Society's Prospect Park Zoo in NY to test hypotheses about the relationships between changes in group composition and social and feeding behavior. Generalized linear mixed models demonstrated that social interactions significantly increased following the compositional changes, even in groups that only experienced member removals. The increase in affiliative social behavior observed suggests that during times of social stress or uncertainty, hamadryas baboons may employ social behavior as a tension-reducing mechanism to negotiate relationships as opposed to using aggression to engage in competitions for ranks and resources. The observed response to compositional changes implies that hamadryas baboons may respond with less aggression than do other Old World monkey species and that levels of affiliative behavior may be a more accurate metric for evaluating introduction success in hamadryas baboons.

The utility of social network analysis for informing zoo management: Changing network dynamics of a group of captive hamadryas baboons (Papio hamadryas) following an introduction of two young males

“…Much of the SNA research involving captive animals has been conducted concerning the effect of environmental changes and the removal of individuals on the social behaviors of primates; however, little research has examined the impacts of the addition of individuals to an established group (Beisner et al, 2011; Beisner et al, 2015; Brent et al, 2011; Flack et al, 2005; Hansen et al, 2009; Less et al, 2010). Ryan and Hauber (2016) examined the compositional changes of a group of captive hamadryas baboons following an introduction of two females. Researchers found that social interactions increased and that behavior was primarily affiliative rather than agonistic.…”

Using social network analysis to inform on the process of one‐male‐unit formation of hamadryas baboons (Papio hamadryas) in captivity

“…Different feeding situations in captivity can affect behavior and social groups in captive baboons. Particularly, aggression between hamadryas baboons is reduced when food is dispersed, rather than clumped (Gil‐Burmann et al, 1998; Ryan & Hauber, 2016). The captive feeding situation can also affect cohesiveness, with OMUs being less cohesive when food is dispersed (Gil‐Burmann et al, 1998).…”

“…Since feeding, space limitations, and relatability are largely different in the wild than in captivity for hamadryas baboons, these studies lead us to believe captivity itself could affect any of the OMU formation pathways. In addition, Ryan and Hauber (2016) did observe social behavior after an introduction of two females to a captive hamadryas baboon group. However, the creation of OMUs after the initial introduction was not organic, as zoo staff removed females from one group to create an entirely separate OMU with the new females and another male.…”

Lengthy leader male tenure delays male offspring dispersal in a primate multilevel society

“…For instance, in a multilevel society of hamadryas baboons (Papio hamadryas), juvenile males leave their natal OMU at around two years of age. These males remain on the periphery of their natal breeding clan, which is composed of several patrilineally related OMUs (Sigg et al, 1982;Bergman et al, 2008;Ryan & Hauber, 2016). Young males that have left their natal OMU employ a "follow-and-wait-strategy" (Mori et al, 2007), occasionally approaching infant and juvenile females to become familiar with these potential future sexual partners (Chalmers, 1986; see also for olive baboons: Danish & Palombit, 2014).…”