Post-conflict opponent affiliation reduces victim re-aggression in a family group of captive arctic wolves (<i>Canis lupus arctos</i>)

<div><p>Post-conflict affiliative interactions have been widely investigated in primates but not extensively in other species. Using the Post Conflict-Matched Control (PC-MC) comparison method, this study investigated the patterns of post-conflict opponent affiliation (POA) of a captive family group of 19 arctic wolves (<i>Canis lupus arctos</i>), investigating the correlation with various factors. We found that POAs occurred mainly in the non-feeding context and more often when the victim was dominant and the aggressor subordinate. Furthermore, POAs were more likely to have been initiated by the victim than the aggressor. Victims’ stress related behaviours occurred more in PC than MC periods, and more after high vs. low intensity aggressions but they were not more likely to occur after conflicts between wolves with a stronger social bond and POAs did not reduce their rate of occurrence. Our results showed that re-aggression was twice less frequent when a friendly interaction occurred between the aggressor and the victim, and consistent with this, victims engaged in POAs more often than the aggressor. Overall, our results support the hypothesis that POAs in wolves may have been selected for as a mechanism to avoid conflict escalation, which could lead to social disruption and hence jeopardize cooperative activities. The high relatedness among individuals in the pack and the greater dependence of all members on cooperation in breeding and hunting may reduce the importance of ‘relationship quality’ as a mediating factor of POAs, although dominance relationships, which are directly linked to the risks of further conflicts, do play an important role.</p></div

Dyadic affiliative score.

<p>Dyadic affiliative score.</p

Temporal distribution of first affiliative interactions in PC and MC periods.

<p>Temporal distribution of first affiliative interactions in PC and MC periods.</p

Effect of rank relationship between opponents on the occurrence of post-conflict affiliative interactions.

<p>Effect of rank relationship between opponents on the occurrence of post-conflict affiliative interactions.</p

Mean latency to the first affiliative interaction in PC and MC periods.

<p>Mean latency to the first affiliative interaction in PC and MC periods.</p

Corrected conciliatory tendencies (CCT), number of attracted, dispersed and neutral pairs for each victim.

<p>Subjects are listed following the rank order.</p

Correlation between the first factor PCA developed for females and: (a) rate of received mounts; (b) proportion of interrupted mounts.

<p>See text for additional explanations.</p

The relation between ‘female reproductive success' and the first factor of the PCA developed for females.

<p>Reproductive success has been assessed as number of puppies survived to maturity. High negative values on factor 1 indicate high-ranking and old females who often led the pack.</p

Results of the general linear models developed for males.

<p>(a) The relation between ‘male copulation tie rate’ and the first factor of the PCA. High negative values on factor 1 indicate high-ranking males who often led the pack, who were frequently approached within 1 metre by females and who displayed both a high rate of affiliative behaviour and a low rate of aggressive behaviour towards females; (b) The relation between “rate of refusals that males received by females” and the second factor of the PCA. High negative values on factor 2 indicate a high rate of aggressive behaviour displayed by males towards females.</p

Results of the principal components analysis (PCA) for females.

<p>The circle shows the correlation between the original variables and the two new components. a  =  female standardized dominance rank, b  =  female leadership score, c  =  female age. Pearson correlations between factor 1 of the PCA and the original variables were: −0.95 (a), −0.99 (b), −0.97 (c); Pearson correlations between factor 2 and the original variables were: −0.31 (a), 0.09 (b), 0.21 (c).</p