Abstract: There are numerous reports of novel learned behaviour patterns in animal populations, yet the factors influencing the invention and spread of these innovations remain poorly understood. Here we investigated to what extent the pattern of spread of innovations in captive groups of starlings, Sturnus vulgaris, could be predicted by knowledge of individual and social group variables, including association patterns, social rank orders, measures of neophobia and asocial learning performance. We presented small groups of starlings with a series of novel extractive foraging tasks and recorded the latency for each bird to contact and solve each task, as well as the orders of contacting and solving. We then explored which variables best predicted the observed diffusion patterns. Object neophobia and social rank measures characterized who was the first of the group to contact the novel foraging tasks, and the subsequent spread of contacting tasks was associated with latency to feed in a novel environment. Asocial learning performance, measured in isolation, predicted who was the first solver of the novel foraging tasks in each group. Association patterns did not predict the spread of solving. Contact latency and solving duration were negatively correlated, consistent with social learning underlying the spread of solving. Our findings indicate that we can improve our understanding of the diffusion dynamics of innovations in animal groups by investigating group-dependent and individual variables in combination. We introduce novel methods for exploring predictors of the origin and spread of behavioural innovations that could be widely applied.

Abstract: Male ungulates engage in intense competition for access to females during the breeding season. Although fights are generally dyadic level encounters, they are on occasion disrupted by the intervention of third-party males. We investigated these third-party interventions using predictions derived from Dugatkin's model (Dugatkin 1998, Proceedings of the Royal Society of London, Series B, 265, 433-437) of intervention behaviour. The model argues that when an individual successfully defeats an opponent there is an increase in the probability of winning a subsequent contest: a winner effect. Third-party intervention behaviour is predicted to occur as it serves to prevent either member of a competing dyad from successfully defeating his opponent, achieving a winner effect and subsequently becoming a threat to the intervener. Consistent with model predictions, our results show that intervening males held significantly higher rank than males that did not intervene and were also more likely to be dominant to both of the competing males. Intervening males did not selectively target competitors based on rank, nor did they target males based on overall dyadic rates of aggression between the intervener and competing males. Furthermore, interveners were more likely to have won their interaction immediately prior to intervention and were also likely to win their interaction subsequent to intervention when compared with contest success of the two competing males. Our results are consistent with predictions that support a winner effect for intervention behaviour in fallow deer fights.

Abstract: Abstract  Affiliative relationships among mares were examined in a managed group of Sorraia horses, Equus caballus, over a 3-year period. We assessed the influence of age, dominance, kinship and reproductive state on the strength of affiliative relationships and diversity of partners. The herd comprised 9–11 mares that had known each other since birth, their foals and a stallion that remained in the group exclusively during the breeding season. In contrast to a previous study, kinship did not significantly affect bonds. Mares tended to spend more time in proximity to those in the same reproductive state. Affiliative relationships among mares were relatively stable but their strength decreased after foaling, possibly as a function of foal protection and bonding between dam and foal. There was no consistent evidence that mares disengaged from affiliative relationships with increasing age. As expected, dominant mares and barren mares contributed the most to affiliative relationships. Dominance rank increased with age, but dominance relationships were stable and did not change after foaling. Overall, reproductive state was the factor that had the most consistent influence on affiliative relationships among Sorraia mares.

Abstract: The role of dominant individuals in leading groups of animals is not yet well understood. We investigated whether dominant beef cows, Bos taurus, have more influence on herd movement on pasture than more subordinate cows. A herd of 15 Gasconne cows was observed for a 3-week period between dawn and dusk. The positions of all adult cows were recorded with GPS collars at 1 min intervals and the behaviour of each cow was recorded in 5 min scans. The dominance hierarchy was recorded by ad libitum sampling. Through cluster analysis of the recorded data, we distinguished three herd behaviour patterns: resting, foraging and travelling. Dominant cows were closer to the front of the herd during both travelling and foraging. During travelling, more dominant cows also had more direct trajectories and were more aligned both with their nearest neighbours and with the whole herd. During foraging, the trajectories of dominant cows were shorter than those of subordinate cows. The results indicate that foraging and short-distance travelling movements by female beef cattle are not led by any particular individual but rather are influenced by a graded type of leadership; that is, the more dominant a cow is, the stronger the influence it may have on the movements of the herd.

Abstract: A previously described (Windschnurer et al., 2009) avoidance distance test was used to assess animals’ fear of humans in order to quantify the human–animal relationship (HAR). This study investigated the influence of the dominant and flightiest animals within a group on the responsiveness of animals during the avoidance distance test. Eighty-eight pregnant heifers comprised of four different genotypes were used (22 animals per genotype): Limousin × Holstein-Friesian, Limousin × Simmental, Charolais × Limousin, and Charolais × Simmental. Sixty of the 88 heifers were group housed (n = 5) into 12 pens with 3 pens per breed, while 28 heifers were singly housed (seven heifers per breed). A reactivity test was performed on days 10, 18, 25 and 30 post-housing on the singly housed heifers, and then on the group housed heifers, on the same days, to calculate a reactivity score. On days 33 and 37 flight and dominance tests, respectively, were performed to identify the flightiest and the dominant animal within each group. On day 41, an avoidance test, measuring both the avoidance distance towards a familiar and an unfamiliar human, was performed on all heifers. No difference (P > 0.05) in reactivity scores was found between the genotypes, between pens for the group housed heifers or between singly housed and group housed heifers (P = 0.28). The avoidance distance (AD) of singly (S) housed heifers towards a familiar (F) (ADSF) human was shorter (P < 0.001) than the avoidance distance of group (G) housed heifers towards an unfamiliar human (ADSU). The ADSF and ADGF were correlated with the ADSU and ADGU (R = 0.87 for singly housed heifers; R = 0.61 for group housed heifers, P < 0.001). For the singly housed heifers, no correlation was observed between reactivity score and ADSF (R = 0.36, P = 0.18), whereas the reactivity score and ADSU were correlated (R = 0.68, P = 0.004). For the group housed heifers no significant correlation was detected between the reactivity score and ADGF (R = 0.18, P = 0.22) or ADGU (R = &#8722;0.11, P = 0.39). No influence of the most dominant animal and the flightiest animals was found on the behaviour of the group in term of avoidance distance and reactivity (P > 0.05). It is concluded that the assessment of the fear of the animals towards humans using the avoidance test at the feed bunk may be useful for singly and group housed heifers and that the leaders of a group such as the flightiest animal or the dominant animal did not influence the avoidance distance test.