Social Dominance in a Gregarious Bird is Related to Body Size But not to Standard Personality Assays

Abstract

The recent growth of research on animal personality could provide new insights into our understanding of sociality and the structure of animal groups. Although simple assays of the type commonly used to study animal personality have been shown to correlate with social aggressiveness in some bird species, conflicting empirical results do not yet make it clear when such assays, typically using isolated individuals, predict behaviour within social groups. We measured aggressiveness in groups of a very gregarious species, the common waxbill (Estrilda astrild), and performed five commonly used behavioural assays on the same individuals: tonic immobility, mirror test, novel object test, open-field test and a variant of the latter in an enriched environment. We found that larger individuals were more dominant and that differences in aggressiveness were repeatable. None of the traditional behavioural assays were related to aggressiveness or dominance. Standard personality assays may fail to capture individual differences relevant to predict social behaviour, and we discuss biological and methodological explanations for these results, such as social behaviour being in part an emergent property of groups rather than an intrinsic property of individuals, or gregarious species being particularly sensitive to the conditions of standard personality assays that test individuals alone.Ethology 121 (2015) 84-93

Morphological Correlates of Personality in Female Asian Particolored Bats (Vespertilio sinensis)

“…Normally, larger individuals in most species have a stronger competitive ability, so it is common for larger individuals to attack smaller ones [103][104][105]. In this study, we found that aggression was significantly and positively associated with BM in Asian particolored bats.…”

Laterality enhances numerical skills in the guppy, Poecilia reticulata

“…It is worth noting that all of these studies refer to aggressive interactions between individuals whereas in the present study we employed the mirror test in a social context. P. reticulata is a strongly schooling species and the mirror test has been widely used in fish to measure social cooperation (De Santi et al, 2001 ; Dadda et al, 2007 ; Karenina et al, 2013 ; Regolin et al, 2013 ; Funghi et al, 2015 ).…”

Boldness traits, not dominance, predict exploratory flight range and homing behaviour in homing pigeons

“…By reducing the time and energy devoted to agonistic encounters, individually beneficial behaviours such as maintenance, vigilance, and foraging can be invested in more heavily [11]. The exact drivers that determine positioning within a dominance hierarchy have been traditionally assumed to include body mass and structural size (reviewed in [14]), but more recently, individual personality traits of group members have been demonstrated to affect dominance [15]. Accordingly, different personality traits may confer different benefits and costs, depending on how they interact with position within a dominance hierarchy.…”