Peace-Making in Marsupials: The First Study in the Red-Necked Wallaby (Macropus rufogriseus)

Abstract

The issue of reconciliation has been widely investigated in many eutherian mammal species. Nevertheless, no data are available for marsupial mammals. Indeed, the majority of reports focus on group dynamics from an ecological and reproductive perspective, but no study has investigated them from a social point of view. We observed the red-necked wallaby colony (Macropus rufogriseus) hosted at the Tierparc Zoo Berlin (Germany) and collected data on aggressive and post-conflict interactions between group members. We found that the phenomenon of reconciliation is present in the study species (mean group CCT 27.40% ±8.89% SE). Therefore, we demonstrated, for the first time, the occurrence of reconciliation in a gregarious marsupial mammal. Post-conflict reunion was not affected by the relationship quality between individuals (friendship or kinship) but it was fine-tuned according to the aggression intensity. For example, low intensity conflicts were reconciled whereas high intensity ones were not. Reconciliation reduced anxiety-related scratching in both of the former opponents and limited further attacks towards the victim during the post-conflict period. These findings suggest that the red-necked wallaby, like many eutherian species, can evaluate the costs of reconciliation and engage in peace-making behavior in the right contexts, in order to maximize its pay-offs.

Social interaction analysis in captive orcas (Orcinus orca)

“…First‐affiliative behaviors occurred earlier after aggressions (on average within the first 3 min) than in control periods. Similarly, conciliations reported in ravens ( Corvus corax ), red‐necked wallabies ( Macropus rufogriseus ), and spotted hyenas ( Crocuta crocuta ) occurred within the first 2–5 min after a conflict (Cordoni & Norscia, ; Fraser & Bugnyar, ; Wahaj et al, ). In a group of captive bottlenose dolphins, the affiliation between former opponents occurred mostly within 1 min after aggression (Yamamoto et al, ).…”

“…However, it is important to note that the value of the CCT found in the present study must be considered with caution due to the small number of PC-MC observations compared to other studies, which used more than 100 pairs of PC-MC observations for the analysis of reconciliation tendencies (e.g., Cordoni & Norscia, 2014;Cozzi et al, 2010;Palagi, Paoli, & Tarli, 2004).…”

“…For non‐human primates, the reported ranges for the CCT are between 7% and 54% (Aureli & de Waal, ). In a captive wallaby colony, the only marsupial mammal reported showing reconciliation, the CCT was 27.4% (Cordoni & Norscia, ), and in a permanent group of horses 26.5% (Cozzi et al, ). Similar to the CCT found in these two last studies, our current finding can be placed in between the minimum of 3.1% found in Japanese macaques (Chaffin, Friedlen, & de Waal, ) and the maximum of 51.4% in crested macaques (Petit, Abegg, & Thierry, ).…”

“…First-affiliative behaviors occurred earlier after aggressions (on average within the first 3 min) than in control periods. Similarly, conciliations reported in ravens (Corvus corax), red-necked wallabies (Macropus rufogriseus), and spotted T A B L E 4 Adjusted residuals for the interactions within each behavioral category and each pair of individuals (emitter in the first column and receiver in the second column) that were performed more (positive sign) or less (negative sign) frequently than expected by chance hyenas (Crocuta crocuta) occurred within the first 2-5 min after a conflict (Cordoni & Norscia, 2014;Fraser & Bugnyar, 2011;Wahaj et al, 2001). In a group of captive bottlenose dolphins, the affiliation between former opponents occurred mostly within 1 min after aggression (Yamamoto et al, 2015).…”

Friend or foe: reconciliation between males and females in wild chacma baboons

“…As this brief overview illustrates, the vast majority of reconciliation research has focused on primates (see Romero & Aureli, 2007, Table 1). Though limited by comparison, systematic studies of reconciliation in non-primate animal societies, including canids (Cools, Van Hout, & Nelissen, 2008;Cordoni & Palagi, 2008), cetaceans (Weaver, 2003), marsupials (Cordoni & Norscia, 2014), hyenas (Wahaj, Guse, & Holekamp, 2001), domestic horses (Cozzi, Sighieri, Gazzano, Nicol, & Baragli, 2010) and goats (Schino, 1998), corvids (Fraser & Bugnyar, 2011), and fish (Bshary & Würth, 2001) have revealed that post-conflict affiliative behaviours are by no means limited to primate or even mammalian taxa, and have provided new insights to the VHR. For example, reconciliation is thought to be largely absent in cooperative breeders because valuable partners (i.e., the breeding pair) rarely engage in aggression (Logan, Emery, & Clayton, 2012;Seed, Clayton, & Emery, 2007).…”