|   | 
Details
   web
Records
Author Sueur, C.; Deneubourg, J.-L.; Petit, O.
Title From Social Network (Centralized vs. Decentralized) to Collective Decision-Making (Unshared vs. Shared Consensus) Type Journal Article
Year 2012 Publication PLoS ONE Abbreviated Journal (down) PLoS ONE
Volume 7 Issue 2 Pages e32566 EP -
Keywords
Abstract <p>Relationships we have with our friends, family, or colleagues influence our personal decisions, as well as decisions we make together with others. As in human beings, despotism and egalitarian societies seem to also exist in animals. While studies have shown that social networks constrain many phenomena from amoebae to primates, we still do not know how consensus emerges from the properties of social networks in many biological systems. We created artificial social networks that represent the continuum from centralized to decentralized organization and used an agent-based model to make predictions about the patterns of consensus and collective movements we observed according to the social network. These theoretical results showed that different social networks and especially contrasted ones – star network vs. equal network – led to totally different patterns. Our model showed that, by moving from a centralized network to a decentralized one, the central individual seemed to lose its leadership in the collective movement's decisions. We, therefore, showed a link between the type of social network and the resulting consensus. By comparing our theoretical data with data on five groups of primates, we confirmed that this relationship between social network and consensus also appears to exist in animal societies.</p>
Address
Corporate Author Thesis
Publisher Public Library of Science Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5712
Permanent link to this record
 

 
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 (down) PLoS ONE
Volume 10 Issue 5 Pages e0126344
Keywords
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>
Address
Corporate Author Thesis
Publisher Public Library of Science Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5992
Permanent link to this record
 

 
Author Sueur, C.; Petit, O.
Title Organization of Group Members at Departure Is Driven by Social Structure in Macaca Type Journal Article
Year 2008 Publication International Journal of Primatology Abbreviated Journal (down) Int. J. Primatol.
Volume 29 Issue 4 Pages 1085-1098
Keywords dominance – kinship – Macaca tonkeana – M. mulatta – network metrics – order – movement
Abstract Abstract  Researchers have often explained order of progression of group members during joint movement in terms of the influence of ecological pressures but rarely that of social constraints. We studied the order of joining by group members to a movement in semifree-ranging macaques with contrasting social systems: 1 group of Tonkean macaques (Macaca tonkeana) and 1 group of rhesus macaques (M. mulatta). We used network metrics to understand roles and associations among individuals. The way the macaques joined a movement reflected the social differences between the species in terms of dominance and kinship. Old and dominant male rhesus macaques were more often at the front of the movement, contrary to the Tonkean macaques, which exhibited no specific order. Moreover, rhesus macaques preferred to join high-ranking or related individuals, whereas Tonkean macaques based associations during joining mostly on sexual relationships with a subgroup of peripheral males.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5125
Permanent link to this record
 

 
Author Bourjade, M.; Thierry, B.; Maumy, M.; Petit, O.
Title Decision-making in Przewalski horses (Equus ferus przewalskii) is driven by the ecological contexts of collective movements Type Journal Article
Year 2009 Publication Ethology Abbreviated Journal (down) Ethology
Volume 115 Issue 4 Pages 321-330
Keywords
Abstract We addressed decision-making processes in the collective movements of

two groups of Przewalski horses (Equus ferus przewalskii) living in a semi

free-ranging population. We investigated whether different patterns of

group movement are related to certain ecological contexts (habitat use

and group activity) and analysed the possible decision-making processes

involved. We found two distinct patterns; ‘single-bout’ and ‘multiplebout’

movements occurred in both study groups. The movements were

defined by the occurrence of collective stops between bouts and differed

by their duration, distance covered and ecological context. For both

movements, we found that a preliminary period involving several horses

occurred before departure. In single-bout movements, all group members

rapidly joined the first moving horse, independently of the preliminary

period. In multiple-bout movements, however, the joining

process was longer; in particular when the number of decision-makers

and their pre-departure behaviour before departure increased. Multiplebout

movements were more often used by horses to switch habitats and

activities. This observation demonstrates that the horses need more time

to resolve motivational conflicts before these departures. We conclude

that decision-making in Przewalski horses is based on a shared consensus

process driven by ecological determinants.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4801
Permanent link to this record
 

 
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 (down) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor 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
Permanent link to this record
 

 
Author Meunier, H.; Leca, J.B.; Deneubourg, J.L.; Petit, O.
Title Group movement decisions in capuchin monkeys: the utility of an experimental study and a mathematical model to explore the relationship between individual and collective behaviours Type Journal Article
Year 2006 Publication Behaviour Abbreviated Journal (down) Behaviour
Volume 143 Issue Pages 1511-1527
Keywords animal society – collective decision-making – primates – group movement – mathematical modeling
Abstract In primate groups, collective movements are typically described as processes dependent on leadership mechanisms. However, in some species, decision-making includes negotiations and distributed leadership. These facts suggest that simple underlying processes may explain certain decision mechanisms during collective movements. To study such processes, we have designed experiments on white-faced capuchin monkeys (Cebus capucinus) during which we provoked collective movements involving a binary choice. These experiments enabled us to analyse the spatial decisions of individuals in the group. We found that the underlying process includes anonymous mimetism, which means that each individual may influence all members of the group. To support this result, we created a mathematical model issued from our experimental data. A totally anonymous model does not fit perfectly with our experimental distribution. A more individualised model, which takes into account the specific behaviour of social peripheral individuals, revealed the validity of the mimetism hypothesis. Even though white-faced capuchins have complex cognitive abilities, a coexistence of anonymous and social mechanisms appears to influence their choice of direction during collective movements. The present approach may offer vital insights into the relationships between individual behaviours and their emergent collective acts.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 2066
Permanent link to this record
 

 
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 (down) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5289
Permanent link to this record
 

 
Author Briard, L.; Deneubourg, J.-L.; Petit, O.
Title How stallions influence the dynamic of collective movements in two groups of domestic horses, from departure to arrival Type Journal Article
Year 2017 Publication Behavioural Processes Abbreviated Journal (down) Behav. Process.
Volume 142 Issue Pages 56-63
Keywords consensus; herding; polygyny; personal leadership; shared decision
Abstract Abstract The role of leader in polygynous species has been solely attributed to the male for some time, but recent studies shown decision making to be distributed within the group. However, the specific reproductive strategy and behavioural repertoire of males in polygynous species such as horses may mean that these individuals still have the potential to play a specific role during decision-making. To investigate this subject, we thoroughly studied the behaviour of two domestic stallions during collective movements of their group. We found that they initiated rarely and sometimes failed to recruit the entire group. When departing as followers, they did not accelerate the joining process. Both stallions preferentially occupied the rear position and exhibited numerous monitoring behaviours. Herding behaviours were performed by only one stallion and mostly occurred outside movement context. Finally, we removed this herding stallion from its group to evaluate how the group dynamic changed. As a result, half of the collective movements were five times slower and mares were more dispersed in comparison when the stallion was in the group. Overall, our results suggest that, the two stallions maintained their role of group monitors from departure to arrival. Their influence on the movement dynamic was indirect and did not play a specific role in the process of decision making.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-6357 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6151
Permanent link to this record
 

 
Author Jacobs, A.; Maumy, M.; Petit, O.
Title The influence of social organisation on leadership in brown lemurs (Eulemur fulvus fulvus) in a controlled environment Type Journal Article
Year 2008 Publication Behavioural Processes Abbreviated Journal (down) Behav. Process.
Volume 79 Issue 2 Pages 111-113
Keywords Animals; *Decision Making; Dominance-Subordination; *Exploratory Behavior; Female; Group Structure; *Leadership; Lemur/*psychology; Male; Sex Factors; *Social Environment
Abstract Studies on leadership during group movements in several lemur species showed that females were responsible for the travelling choices concerning time and direction. Interestingly, in these species females are dominant over males. We investigated the influence of social organisation upon leadership processes by studying a lemur species in which social organisation is characterized by the absence of female dominance: the brown lemur (Eulemur fulvus fulvus). The study was conducted on a semi-free ranging group of 11 individuals and the analysis performed on 69 group movements showed that all the individuals could initiate a group movement. In 34 cases, the whole group moved. There was no significant difference in the number of start attempts or in the number of group members involved from one initiator to another. Moreover, there was no effect of sex or age of the initiator on the number of individuals following it or on the speed of the joining process. Therefore, the leadership observed is widely distributed to all group members. These results support the hypothesis of an influence of social organisation upon the decision-making processes but still remain to be studied in a more relevant ecological context.
Address IPHC-DEPE, Equipe d'ethologie des primates, UMR 7178, Centre National de la Recherche Scientifique-Universite Louis Pasteur and Centre de Primatologie, Strasbourg, France
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-6357 ISBN Medium
Area Expedition Conference
Notes PMID:18586413 Approved no
Call Number Equine Behaviour @ team @ Serial 5127
Permanent link to this record
 

 
Author Sueur, C.; Petit, O.
Title Shared or unshared consensus decision in macaques? Type Journal Article
Year 2008 Publication Behavioural Processes Abbreviated Journal (down) Behav. Process.
Volume 78 Issue 1 Pages 84-92
Keywords Collective movement; Decision-making; Leadership; Social style
Abstract Members of a social group have to make collective decisions in order to synchronise their activities. In a shared consensus decision, all group members can take part in the decision whereas in an unshared consensus decision, one individual, usually a dominant member of the group, takes the decision for the rest of the group. It has been suggested that the type of decision-making of a species could be influenced by its social style. To investigate this further, we studied collective movements in two species with opposed social systems, the Tonkean macaque (Macaca tonkeana) and the rhesus macaque (Macaca mulatta). From our results, it appears that the decision to move is the result of the choices and actions of several individuals in both groups. However, this consensus decision involved nearly all group members in Tonkean macaques whereas dominant and old individuals took a prominent role in rhesus macaques. Thus, we suggest that Tonkean macaques display equally shared consensus decisions to move, whereas in the same context rhesus macaque exhibit partially shared consensus decisions. Such a difference in making a collective decision might be linked to the different social systems of the two studied species.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-6357 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5129
Permanent link to this record