Wild jackdaws respond to their partner's distress, but not with consolation

Abstract

Individuals are expected to manage their social relationships to maximize fitness returns. For example, reports of some mammals and birds offering unsolicited affiliation to distressed social partners (commonly termed 'consolation') are argued to illustrate convergent evolution of prosocial traits across divergent taxa. However, most studies cannot discriminate between consolation and alternative explanations such as self-soothing. Crucially, no study that controls for key confounds has examined consolation in the wild, where individuals face more complex and dangerous environments than in captivity. Controlling for common confounds, we find that male jackdaws (Corvus monedula) respond to their mate's stress-states, but not with consolation. Instead, they tended to decrease affiliation and partner visit rate in both experimental and natural contexts. This is striking because jackdaws have long-term monogamous relationships with highly interdependent fitness outcomes, which is precisely where theory predicts consolation should occur. Our findings challenge common conceptions about where consolation should evolve, and chime with concerns that current theory may be influenced by anthropomorphic expectations of how social relationships should be managed. To further our understanding of the evolution of such traits, we highlight the need for our current predictive frameworks to incorporate the behavioural trade-offs inherent to life in the wild.

Keywords: animal cognition; behavioural ecology; consolation; corvids; prosociality; social cognition.

Figure 1.

Behaviour changes across the pre- and post-stressor period, at the scale of the whole video. Panel (a) shows the percentage of female time in the nest-box spent in male-initiated direct affiliation; (b) shows the percentage of female time in the nest-box that the male spent with the female; (c) shows the number of food-sharing visits made by the male, controlled for female time in the box; (d) shows the male's visit number, controlled for video length. Grey ties connect the same individuals.