Factors influencing the formation and maintenance of all‐male gorilla groups in captivity

Abstract

The social housing of males is of particular importance for captive managers of polygynous species. In this work, we highlight nine areas we believe are important to the successful formation and maintenance of all‐male gorilla groups. Although more data are still needed to complete our understanding of these groups, the general picture that emerges is that all‐male groups can be a functional social unit for male gorillas, the longevity of which might be improved by careful planning. It appears that the best time to form all‐male groups is when the animals are still immature, as males in this age class have been observed to form some of the most stable groups. Efforts should be made to diversify the groups in terms of rearing history, particularly with respect to hand‐reared males, and to limit the amount of hand rearing experienced by males. Groups probably should contain no more than three or four adult males. Exhibits should be designed to provide visual barriers, refuges for subordinate animals, the means to separate individuals, and possibly the means to isolate all‐male groups from mixed‐sex groups. Additionally, because it is likely that some males will have to be removed from all‐male groups, zoos need to design facilities that provide state‐of‐the‐art housing for solitary individuals. It is hoped that by identifying bachelor males early in life and establishing cooperative management plans across institutions, zoos will be able to provide beneficial, long‐term social situations for all male gorillas in captivity. Zoo Biol 23:189–203, 2004. © 2004 Wiley‐Liss, Inc.

Facility design for Bachelor Gorilla groups

“…In zoos, males are successfully maintained in bachelor groups particularly when introduced at a young age in similar age cohorts and when groups are limited in size to three individuals, on average [Stoinski et al, 2004b]. Groups may experience higher rates of success when composed of mother-reared individuals [Stoinski et al, 2004b] who have tolerant personality profiles, illustrated by high rates of affiliative behavior and low rates of agonistic behavior .…”

“…Successful propagation of Western lowland gorillas in North American zoos has led to a growing need for bachelor gorilla groups [Stoinski et al, 2004b]. The most recent Population Analysis and Breeding Plan for the Western Lowland Gorilla SSP [Lukas et al, 2007] reports that of 173 male gorillas in the population, 58 are housed in 20 bachelor groups at 16 zoos.…”

“…Additional exhibit design information is available in the design section of the Gorilla Species Survival Plan s (SSP) Husbandry Manual [Lash et al, 1997] and elsewhere [Association of Zoos and Aquariums, 2008;Stoinski et al, 2004b].…”

Studying primate personality in zoos: implications for the management, welfare and conservation of great apes

“…In Europe, the United States and Japan there have been a large number of studies on primate cognition (Hopper, 2017). However, very little research is carried out on personality, and even less on the link between personality and behaviour (Stoinski et al, 2004). Moreover, methodological studies, such as validating personality-trait ratings with behavioural observations, are often the focus of this work.…”

“…This could lead to a reduction of aggressive encounters, because gorillas rated lower for Understanding were also more likely to engage in noncontact aggression (Kuhar et al, 2006). It has been suggested that gorilla groups should be formed when the apes are young for the best outcomes (Stoinski et al, 2004), so it is vital to understand any agerelated differences in personality, but this is not always possible in zoos (see Huskisson & Chism, 2018 (King, J. E., et al, 2008). In orangutans, Agreeableness declines with age, and while Extraversion also decreases as orangutans age, it does so differently from Chimpanzees (Weiss & King, 2015).…”