Patterns of wounding in hamadryas baboons (Papio hamadryas) in North American zoos

Abstract

In North American zoos, hamadryas baboons (Papio hamadryas) have traditionally been housed as single one-male units (single male groups). In recent years, efforts have been made to house hamadryas in groups composed of multiple one-male units (multi-male groups) to more closely mirror their natural social structure, in addition to all-male or bachelor groups to manage surplus males. Given that the majority of social conflict in hamadryas occurs between males during the acquisition and defense of females, it was thought that managing hamadryas in these multi-male groups would result in increased rates of wounding. To assess this, incidences of wounding were recorded over one year across seven zoos (10 social groups, 59 individuals). Overall, we found no difference in wounding rates between group types, or by sex, and group type. These data provide evidence that managing hamadryas in multi-male and bachelor groups is an effective husbandry practice that does not negatively impact the welfare of the individuals, in addition to providing a more species-appropriate social setting for hamadryas in zoos. As the management of hamadryas in multi-male and bachelor groups continues and expands, additional research will be needed to understand what factors contribute to optimal cohesion, and welfare of groups and if wounding rates change as group size continues to increase.

Sex and season predict wounds in zoo‐housed Japanese macaques (Macaca fuscata): A multi‐institutional study

“…Despite the agonistic tendencies reported for Japanese macaques, the wounding rate reported here (4.6 wounds annually per individual, on average) is similar to the rate reported recently in a multi‐zoo study of gorilla wounding (4.8 wounds per year; Leeds et al, 2015), and less than half the rate reported in an earlier study of chimpanzee wounding (9.48 wounds per year; Ross et al, 2009). Japanese macaques did receive more wounds than hamadryas baboons; however (3.36 wounds per year; Wiley et al, 2018). Japanese macaques are typically characterized as very low tolerance with high rates of aggressive interactions, unlike gorillas and chimpanzees; therefore, these comparative patterns highlight the potential for a dissociation between aggressive behavior and wounding.…”

“…The methods of this study were modeled after previous studies investigating the factors associated with wounding in zoo‐housed primates (Leeds et al, 2015; Ross et al, 2009; Wiley et al, 2018). Each participating institution received a detailed set of instructions in June 2016 and care staff at the institution were advised to record all incidences of wounding observed ad libitum beginning as soon as their institutional practices allowed.…”

“…These authors found that the presence of young silverback male gorillas was positively correlated with wounding rates while, contrary to common thought, there was no difference between mixed‐sex and bachelor groups. In a third study, Wiley and colleagues (Wiley, Leeds, Carpenter, & Kendall, 2018) applied a similar methodology to study wounding in hamadryas baboons ( Papio hamadryas ) across seven zoos and found that hamadryas baboons living in multi‐male, multi‐female groups and multi‐male bachelor groups were not experiencing higher wounding rates than single‐male groups. In all three studies, the process of evaluating patterns of wounding provided insight that helped guide decisions on how to manage these species in zoos.…”

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

“…However, captive protocols require zoo staff to step in if aggression becomes so extreme in frequency or severity that it affects the welfare of the animals (AZA, 2020, p. 13; Minier, personal communication, 2/20/2020). In addition, wounding rates in hamadryas baboons are low in captivity (Wiley et al, 2017). Our results show that aggression between the two subadult males and the alpha male did occur over the 6 months, but did not increase during the project timeline, even after Kusa formed his OMU with Kodee.…”

“…In addition, while there is no competition between neighboring bands in captivity, there is still the potential for competition between sexually maturing males within one clan if multiple OMUs are housed together in an exhibit. Despite the potential for increased aggression, in recent years, the hamadryas Species Survival Plan (SSP®) has encouraged the formation of several OMUs in one larger social group in captivity, as this will more closely resemble the wild social environment (Wiley et al, 2017). Therefore, finding appropriate ways to manage and understand key life‐history moments and species‐specific behaviors of these monkeys is a necessity for captive populations.…”