Abstract: The relationship between social behaviour and skin injuries (caused by horns) of loose housed horned cows was investigated on 35 dairy farms. While the frequencies of two agonistic behaviour elements (push and chase away) were positively correlated with the occurrence of skin injuries, the frequencies of butting and homing were not. Butting appears to have an ambivalent motivation, in that its occurrence is correlated positively both with agonistic behaviour and with social licking. Horning showed a positive correlation with social licking only. Four groups of husbandry conditions that may be associated with the occurrence of social behaviour and of injuries were distinguished: i) herd management, with variables including problem solving management by the farmer, integration of new cows, and dealing with periparturient and oestrus cows; ii) human-animal relationship, with variables including ability to identify individual cows, frequency of brushing the cows, number of milkers, and frequency of personnel changes; iii) animal characteristics, with the variable of herd size; and iv) stable characteristics, with the variable of space per cow (m2). The relevance of the husbandry variables investigated here had been confirmed in a previous stepwise regression analysis (Menke 1996). The variables for herd management and human-animal relationship conditions correlated in a consistent way with the occurrence of agonistic behaviour and/or of injuries, while most of them also correlated in the opposite direction with the occurrence of social licking. Herd size correlated positively with agonistic behaviour, but negatively with social licking. Space per cow correlated negatively with agonistic behaviour and injuries. In more than 70 per cent of the herds investigated, the levels of agonistic behaviour and of skin injuries were low, implying that horned dairy cows can be kept with less risk than is often assumed. We argue that such risks strongly depend on management factors that can be improved.

Abstract: Social dynamics and maintenance of social cohesion were studied by analysing social interventions in two groups of horses consisting of adult mares, their offspring, adult geldings and sub-adults. The animals were observed for a total of 1316 h. All relevant dyadic and triadic social interactions, including initial behaviour, possible intervention and outcome, were recorded. The main question was: do horses use interventions in affiliative interactions to safeguard their social network? Horses were significantly more likely to intervene in allogrooming or play interactions that involved a preferred partner. The stronger the preferred association in allogrooming, the higher the likelihood the intervener took over allogrooming with an initial dyad member. Interveners originating from two newly introduced groups (n = 3 and 5), intervened significantly more often when a member of their own group allogroomed with an unfamiliar horse. In play, no correlation with unfamiliarity was found. Overall, the intervening horses stopped more than half of the initial allogrooming interactions, and a third of all interactions. Therefore, social facilitation cannot sufficiently explain interference behaviour. This study shows that maintaining relationships with preferred partners is important to horses and has implications for equine husbandry and management.

Abstract: Interventions occur when animals interfere in competitive interactions between two or more individuals. Interveners can alter the nature of the ongoing interaction by targeting one party (attacking, biting) and supporting the other. Three theories have been proposed to account for intervention behaviour: kin selection, reciprocity and direct benefits. The kin selection hypothesis predicts that interveners will selectively support relatives over nonrelatives; the reciprocity hypothesis predicts that when intervener [`]A' supports individual [`]B', later [`]B' will intervene and support [`]A'; and the direct benefits hypothesis predicts that target/support patterns should serve the immediate interests of the intervener. We tested the reciprocity and direct benefits hypotheses by exploring third-party interventions in play fighting among littermates of domestic dogs. Interveners in dyadic play did not preferentially target or support preferred playmates of the intervener. Interveners targeted the dog in the losing role at the time of the intervention, and they did not show reciprocity in support. Taken together, these last two findings suggest that littermates benefit directly and use interventions opportunistically to practise offence behaviours directed at littermates already behaving subordinately. Opportunities to practise targeting in a playful setting may help structure dominance relationships among littermates. Additionally, the tendency for puppies to do what the other is doing (target the dog in the losing role) may pave the way for synchronizing cooperative behaviours during group hunting and territorial defence. The types of behaviours used to intervene changed over development, but the outcome following an intervention remained stable.

Abstract: Self‐organizing‐system approaches have shed significant light on the mechanisms underlying synchronized movements by large groups of animals, such as shoals of fish, flocks of birds, or herds of ungulates. However, these approaches rarely consider conflicts of interest between group members, although there is reason to suppose that such conflicts are commonplace. Here, we demonstrate that, where conflicts exist, individual members of self‐organizing groups can, in principle, increase their influence on group movement destination by strategically changing simple behavioral parameters (namely, movement speed, assertiveness, and social attraction range). However, they do so at the expense of an increased risk of group fragmentation and a decrease in movement efficiency. We argue that the resulting trade‐offs faced by each group member render it likely that group movements are led by those members for which reaching a particular destination is most crucial or group cohesion is least important. We term this phenomenon leading according to “need” or “social indifference,” respectively. Both kinds of leading can occur in the absence of knowledge of or communication about the needs of other group members and without the assumption of altruistic cooperation. We discuss our findings in the light of observations on fish and other vertebrates.

Abstract: A group of animals can only move cohesively, if group members “somehow” reach a consensus about the timing (e.g., start) and the spatial direction/destination of the collective movement. Timing and spatial decisions usually differ with respect to the continuity of their cost/benefit distribution in such a way that, in principle, compromises are much more feasible in timing decision (e.g. median preferred time) than they are in spatial decisions. The consequence is that consensus costs connected to collective timing decisions are usually less skewed amongst group members than are consensus costs connected to spatial decisions. This, in turn, influences the evolution of decision sharing: sharing in timing decisions is most likely to evolve when conflicts are high relative to group cohesion benefits, while sharing in spatial decisions is most likely to evolve in the opposite situation. We discuss the implications of these differences for the study of collective movement decisions.