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Author Petit, O.; Bon, R.
Title Decision-making processes: The case of collective movements Type Journal Article
Year 2010 Publication Behavioural Processes Abbreviated Journal Behav. Process.
Volume 84 Issue 3 Pages 635-647
Keywords Consensus; Inter-individual relationships; Leadership; Self-organization; Social status
Abstract Besides focusing on the adaptive significance of collective movements, it is crucial to study the mechanisms and dynamics of decision-making processes at the individual level underlying the higher-scale collective movements. It is now commonly admitted that collective decisions emerge from interactions between individuals, but how individual decisions are taken, i.e. how far they are modulated by the behaviour of other group members, is an under-investigated question. Classically, collective movements are viewed as the outcome of one individual's initiation (the leader) for departure, by which all or some of the other group members abide. Individuals assuming leadership have often been considered to hold a specific social status. This hierarchical or centralized control model has been challenged by recent theoretical and experimental findings, suggesting that leadership can be more distributed. Moreover, self-organized processes can account for collective movements in many different species, even in those that are characterized by high cognitive complexity. In this review, we point out that decision-making for moving collectively can be reached by a combination of different rules, i.e. individualized (based on inter-individual differences in physiology, energetic state, social status, etc.) and self-organized (based on simple response) ones for any species, context and group size.
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ISSN 0376-6357 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5217
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Author Petit, O.; Thierry, B.
Title Aggressive and peaceful interventions in conflicts in Tonkean macaques Type Journal Article
Year 1994 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.
Volume 48 Issue 6 Pages 1427-1436
Keywords
Abstract Abstract. Peaceful interventions in conflicts are an extremely rare phenomenon in most primate species. In contrast to aggressive interventions, they cannot lead to gains in terms of competition. To clarify the function and origin of this behaviour, the patterning and consequences of peaceful and aggressive interventions were studied in a semi-free ranging group of tonkean macaques, Macaca tonkeana. Intense conflicts frequently elicited both types of intervention. Interveners preferentially targeted the initiator of the conflict, who was generally the dominant of the two opponents. Males tended to intervene more than females, especially using peaceful interventions. Interventions were frequently performed on behalf of the most closely kin-related opponent; this was true particularly for aggressive interventions. In peaceful interventions, the intervener was usually dominant over both parties. Lipsmacking, clasping, mounting and social play were mainly used, and were successful in halting aggression. Peaceful interventions were frequently followed by an affinitive interaction, such as grooming, between intervener and target. Peaceful interventions thus appear to protect the beneficiary while preserving the social relationship between intervener and target. The origin of the behaviour can be traced to the epigenetic constraints arising from the species-specific social organization.
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ISSN 0003-3472 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5244
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Author Ramseyer, A.; Petit, O.; Thierry, B.
Title Decision-making in group departures of female domestic geese Type Journal Article
Year 2009 Publication Behaviour Abbreviated Journal Behaviour
Volume 146 Issue Pages 351-371
Keywords MOVEMENT; COLLECTIVE; PRE-DEPARTURE; RECRUITMENT; ANSER DOMESTICUS
Abstract Group-living animals have to make trade-offs to reach consensus and travel together. We investigated the recruitment processes underpinning decision-making at departure in a group of 20 female domestic geese (Anser domesticus) kept in semi-free-range conditions. Two observers continuously videotaped the behaviours of the birds. Data were analyzed using multiple regression analyses. We found that decision-making was a continuous and distributed process. Departure was preceded by an increase in the arousal state of group members and their initial orientation influenced recruitment. Patterns of group movement could be predicted from the behaviours of individuals before departure. Individuals' locations, moves and signals could act as passive or communicative cues. A higher number of vocalisations and arousal behaviours led to a larger number of individuals recruited. Some individuals were more efficient than others in recruiting followers but any geese could initiate a movement. First movers recruited a higher number of mates when they had a greater number of neighbours. Not only the first mover but also the behaviours of the second and third movers prompted further individuals to follow. There was no evidence that geese were able to intentionally recruit others, rather they synchronized and adjusted each other's motives until reaching a consensus.
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5289
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Author Bourjade, M.; Thierry, B.; Hausberger, M.; Petit, O.
Title Is <italic>Leadership</italic> a Reliable Concept in Animals? An Empirical Study in the Horse Type Journal Article
Year 2015 Publication PLoS ONE Abbreviated Journal PLoS ONE
Volume 10 Issue 5 Pages e0126344
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Abstract <p>Leadership is commonly invoked when accounting for the coordination of group movements in animals, yet it remains loosely defined. In parallel, there is increased evidence of the sharing of group decisions by animals on the move. How leadership integrates within this recent framework on collective decision-making is unclear. Here, we question the occurrence of leadership in horses, a species in which this concept is of prevalent use. The relevance of the three main definitions of leadership – departing first, walking in front travel position, and eliciting the joining of mates – was tested on the collective movements of two semi-free ranging groups of Przewalski horses (<italic>Equus ferus przewalskii</italic>). We did not find any leader capable of driving most group movements or recruiting mates more quickly than others. Several group members often displayed pre-departure behaviours at the same time, and the simultaneous departure of several individuals was common. We conclude that the decision-making process was shared by several group members a group movement (i.e., partially shared consensus) and that the leadership concept did not help to depict individual departure and leading behaviour across movements in both study groups. Rather, the different proxies of leadership produced conflicting information about individual contributions to group coordination. This study discusses the implications of these findings for the field of coordination and decision-making research.</p>
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Publisher Public Library of Science Place of Publication Editor
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5992
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Author Briard, L.; Dorn, C.; Petit, O.
Title Personality and Affinities Play a Key Role in the Organisation of Collective Movements in a Group of Domestic Horses Type Journal Article
Year 2015 Publication Ethology Abbreviated Journal Ethology
Volume 121 Issue 9 Pages 888-902
Keywords decision-making; equids; hierarchy; leadership; social network
Abstract Understanding how groups of individuals with different motives come to daily decisions about the exploitation of their environment is a key question in animal behaviour. While interindividual differences are often seen only as a threat to group cohesion, growing evidence shows that they may to some extent facilitate effective collective action. Recent studies suggest that personality differences influence how individuals are attracted to conspecifics and affect their behaviour as an initiator or a follower. However, most of the existing studies are limited to a few taxa, mainly social fish and arthropods. Horses are social herbivores that live in long-lasting groups and show identifiable personality differences between individuals. We studied a group of 38 individuals living in a 30-ha hilly pasture. Over 200 h, we sought to identify how far individual differences such as personality and affinity distribution affect the dynamic of their collective movements. First, we report that individuals distribute their relationships according to similar personality and hierarchical rank. This is the first study that demonstrates a positive assortment between unrelated individuals according to personality in a mammal species. Second, we measured individual propensity to initiate and found that bold individuals initiated more often than shy individuals. However, their success in terms of number of followers and joining duration did not depend on their individual characteristics. Moreover, joining process is influenced by social network, with preferred partners following each other and bolder individuals being located more often at the front of the movement. Our results illustrate the importance of taking into account interindividual behavioural differences in studies of social behaviours.
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Series Editor (up) Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-0310 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6153
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