Social encounters produce different autonomic response between dominants and subordinates in crows

Abstract

Recent studies of behavioural physiology on animals have suggested the crucial role of peripherally physiological signals in eliciting arousal and emotion. Heart rate (HR) is one of the useful and critical signals to measure autonomic regulation as a physiological basis for arousal and emotion in response to biologically significant stimuli such as social encounter with conspecific individuals. However, our understanding of peripherally physiological response such as HRs and autonomic activities under social contexts of non-human animals is still limited, particularly in birds. Here, we examined the autonomic activity of behaving crows exposed to a dominant and a subordinate conspecific by using non-invasive electrocardiogram recording. We found different patterns of autonomic responses dependent on the relative dominance position: dominant crows encountering subordinates showed the elevation of sympathetic activity, whereas subordinates encountering dominants showed decreased HR with elevated parasympathetic activity. This is the first study in birds to report different autonomic responses dependent on relative dominance positions during dyadic social encounters. The present study advances our understanding of the role of the peripheral autonomic system, as an interactive system with the brain, in eliciting emotion/arousal associated with socially challenging environments from an evolutionary perspective.

Vasopressin 1a receptor antagonist disrupts male-male affiliative relationships formed by triadic cohabitation in large-billed crows

“…Seventeen birds were assigned to eight triads for the cohabitation experiment (Table 1). For the triad group assignment, the relative dominance between each of the two birds was determined through three trials of dyadic social encounters in an indoor aviary (W 2 m × D 2 m × H 2 m) using a procedure similar to that reported in previous studies [48, 52]. In each trial, two birds were given a 5-min opportunity to freely interact, and the winner and loser were determined according to the behavioural criteria used in previous studies [40, 48, 52].…”

“…For the triad group assignment, the relative dominance between each of the two birds was determined through three trials of dyadic social encounters in an indoor aviary (W 2 m × D 2 m × H 2 m) using a procedure similar to that reported in previous studies [48, 52]. In each trial, two birds were given a 5-min opportunity to freely interact, and the winner and loser were determined according to the behavioural criteria used in previous studies [40, 48, 52]. Specifically, the loser was identified as an individual exhibiting submissive behaviour (i.e., submissive begging vocalisation and/or avoidance) in response to aggressive behaviour (i.e., jab, peck, aggressive vocalisation, and approach).…”

“…The trial procedure was identical to that of Experiment 1, and the birds were allowed to interact freely for 30 min. Given the typical social behaviour in the dyad and interactions between dominant and subordinate large-billed crows [40, 48, 52], we coded allopreening; aggressive behaviour such as peck, jab, and kick; and submissive begging vocalisations from video-recorded data for offline analysis. The inter-trial interval was three and five days.…”

“…Before this experiment, dominance relationships of all dyads used in this study were assessed using a social dyadic encounter paradigm from previous studies (Nishizawa et al, 2011;Takeda et al, 2022). Briefly, two birds were introduced into an aviary to freely interact for 5 min in three trials within a 2-day inter-trial interval.…”

“…Additionally, individuals form multiple highly differentiated affiliative and agonistic relationships with others that comprise various qualities (Fraser & Bugnyar, 2010a). Males form and maintain stable dyadic dominance relationships and, in a group setting, a strict linear hierarchy, whereas those of females are less robust (Fraser & Bugnyar, 2010a;Izawa & Watanabe, 2008;Nishizawa et al, 2011;Ode et al, 2015;Takeda et al, 2022).…”