Evaluation of social compatibility in an all-male group of chimpanzees (Pan troglodytes) by means of social network analysis

The study here presented provides preliminary data regarding social compatibility of an all-male group of five chimpanzees (Pan troglodytes), assessed by means of a social network analysis (SNA). The study was conducted at the Fundacio Mona (Girona, Spain), where data on social behavior were collected in two consecutive 2-week periods using continuous focal animal sampling for a total of 72 h of observation. Our results show the study group is socially compatible: males showed high levels of affiliative behaviors (grooming) and low levels of aggressive behaviors (displacement, display, physical aggression, supplantation). In addition, these results remained stable during the two study periods. Likewise, the most central individuals in the affiliative and aggressive networks were identified, showing slight variations depending on the period of the study. Therefore, the information obtained suggests that placing male chimpanzees in all-male groups could be a potential option for the management of surplus males. The results also provide support regarding the positive contribution of social assessment to the management of captive primate groups. In this regard, SNA seems to be a useful tool to evaluate the groups' social behavior and to identify its key individuals. In addition, these results allow us to draw up a set of recommendations before the formation of an all-male group, but also to assess their compatibility once groups have been formed. As a whole, the results of this study could improve the management of endangered species like chimpanzees.