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Author Hemelrijk, C. K.; Wantia, J,; Isler, K. doi  openurl
  Title Female Dominance over Males in Primates: Self-Organisation and Sexual Dimorphism Type Journal Article
  Year 2008 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 3 Issue 7 Pages e2678  
  Keywords  
  Abstract The processes that underlie the formation of the dominance hierarchy in a group are since long under debate. Models of self-organisation suggest that dominance hierarchies develop by the self-reinforcing effects of winning and losing fights (the so-called winner-loser effect), but according to ‘the prior attribute hypothesis’, dominance hierarchies develop from pre-existing individual differences, such as in body mass. In the present paper, we investigate the relevance of each of these two theories for the degree of female dominance over males. We investigate this in a correlative study in which we compare female dominance between groups of 22 species throughout the primate order. In our study female dominance may range from 0 (no female dominance) to 1 (complete female dominance). As regards ‘the prior attribute hypothesis’, we expected a negative correlation between female dominance over males and species-specific sexual dimorphism in body mass. However, to our surprise we found none (we use the method of independent contrasts). Instead, we confirm the self-organisation hypothesis: our model based on the winner-loser effect predicts that female dominance over males increases with the percentage of males in the group. We confirm this pattern at several levels in empirical data (among groups of a single species and between species of the same genus and of different ones). Since the winner-loser effect has been shown to work in many taxa including humans, these results may have broad implications.3  
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  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5115  
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Author Sueur, C.; Petit, O. url  doi
openurl 
  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 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.  
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  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5125  
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Author Sueur, C.; Petit, O. url  doi
openurl 
  Title Shared or unshared consensus decision in macaques? Type Journal Article
  Year 2008 Publication Behavioural Processes Abbreviated Journal 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.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5129  
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Author Stueckle, S.; Zinner, D. url  doi
openurl 
  Title To follow or not to follow: decision making and leadership during the morning departure in chacma baboons Type Journal Article
  Year 2008 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 75 Issue 6 Pages 1995-2004  
  Keywords chacma baboon; collective movement; consensus; decision making; leadership; Papio hamadryas ursinus  
  Abstract To benefit from group living, group members need to keep the group cohesive by coordinating time and direction of travelling. Self-organization and leadership are two means of coordination and two types of decision can be made on the group level: combined and consensus. We studied the initiation process of group movements during the morning departure of a group of chacma baboons, Papio hamadryas ursinus, from its sleeping site in De Hoop Nature Reserve, South Africa. Findings from other female-bonded primate groups led us to hypothesize that females should play a major role in the decision-making process. Approximately 75% of the adults made a start attempt, with 62 of 92 attempts being by males. There was no sex difference in the probability of being successful when initiating an attempt. Lactating females initiated fewer than pregnant or cycling females. Thus, at least for this group of chacma baboons, leadership appeared to be distributed and the decision about the timing of departure and travel direction seemed to be a partially shared consensus decision with adult males contributing more to the decision outcome, with a slightly more prominent role of the dominant male. Our results do not support the [`]leading females' hypothesis. No behavioural patterns that might serve as specialized signals leading to a more successful recruitment of other group members were observed. The departure process appeared to be coordinated merely through individuals setting an example by moving off.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-3472 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5130  
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Author Croft, D. P.; James, R..; Krause, J. (eds) url  isbn
openurl 
  Title Exploring Animal Social Networks Type Book Whole
  Year 2008 Publication Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Princton University Press Place of Publication Princton Editor Croft, D. P.; James, R..; Krause, J.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 9780691127521 Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5139  
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Author Lansade, L.; Bouissou, M.-F.; Erhard, H.W. url  doi
openurl 
  Title Fearfulness in horses: A temperament trait stable across time and situations Type Journal Article
  Year 2008 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 115 Issue 3-4 Pages 182-200  
  Keywords Horse; Temperament; Fearfulness; Novelty; Suddenness; Behavioural tests  
  Abstract The purpose of this study was to test the existence of a “fearfulness” trait in horses, by testing the stability across situations and over time of the responses to different fear-eliciting situations. It was also to identify which behavioural parameters are the best indicators of this trait. Sixty-six Welsh ponies and 44 Anglo-Arab horses were successively tested at 8 months and 1.5 years of age. Of these, 33 Welsh ponies and 21 Anglo-Arabs were also tested at 2.5 years of age. At each age, they were subjected to four test situations. The first test involved the introduction of a novel object in the test pen (novel object test). In the second test, a novel area was placed in the pen between the horse and a bucket of food, to determine the time the horse took to cross the area (novel area test). Finally, the third test consisted in suddenly opening an umbrella in front of the horse while it was eating (surprise test). During these tests, many behavioural parameters were recorded. A fourth test consisted of a surprise test during which the horse was held by a handler while its heart rate was measured. Spearman correlations were used to identify links between behavioural parameters measured during different tests and between different ages. Reactions to the first three tests showed consistency between them and over time. Among all the behavioural parameters measured during these tests, some presented high stability over time and were well correlated with behaviours expressed during other tests, indicating they are the best indicators of a fearfulness trait: the frequency of licking/nibbling the novel object, the time to put one foot on the novel area and to eat from a bucket placed just behind it, and the flight distance and the time to eat under the opened umbrella. The stability across responses expressed in various fear-eliciting events and over time from 8 months to 2.5 years of age suggests the existence of a [`]fearfulness' trait in horses. The different indexes of heart rate measured or calculated during the surprise effect present limited stability over time and almost no correlation with the behavioural parameters measured during the other three tests. We conclude that, in contrast to the previously mentioned behaviours, these are not reliable measures of a temperament trait. From a practical point of view, this study shows that it is possible to identify a horse's level of fearfulness as early as 8 months of age using the first three tests.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-1591 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5167  
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Author Lusseau, D.; Whitehead, H.; Gero, S. url  doi
openurl 
  Title Incorporating uncertainty into the study of animal social networks Type Journal Article
  Year 2008 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 75 Issue 5 Pages 1809-1815  
  Keywords bootstrap; social behaviour; social network; social structure  
  Abstract  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-3472 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5173  
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Author Hemelrijk, C.K.; Hildenbrandt, H. url  doi
openurl 
  Title Self-Organized Shape and Frontal Density of Fish Schools Type Journal Article
  Year 2008 Publication Ethology Abbreviated Journal Ethology  
  Volume 114 Issue 3 Pages 245-254  
  Keywords  
  Abstract Abstract Models of swarming (based on avoidance, alignment and attraction) produce patterns of behaviour also seen in schools of fish. However, the significance of such similarities has been questioned, because some model assumptions are unrealistic [e.g. speed in most models is constant with random error, the perception is global and the size of the schools that have been studied is small (up to 128 individuals)]. This criticism also applies to our former model, in which we demonstrated the emergence of two patterns of spatial organization, i.e. oblong school form and high frontal density, which are supposed to function as protection against predators. In our new model we respond to this criticism by making the following improvements: individuals have a preferred ‘cruise speed’ from which they can deviate in order to avoid others or to catch up with them. Their range of perception is inversely related to density, with which we take into account that high density limits the perception of others that are further away. Swarm sizes range from 10 to 2000 individuals. The model is three-dimensional. Further, we show that the two spatial patterns (oblong shape and high frontal density) emerge by self-organization as a side-effect of coordination at two speeds (of two or four body lengths per second) for schools of sizes above 20. Our analysis of the model leads to the development of a new set of hypotheses. If empirical data confirm these hypotheses, then in a school of real fish these patterns may arise as a side-effect of their coordination in the same way as in the model.  
  Address  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd 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 (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5202  
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Author Mirabet, V.; Fréon, P.; Lett, C. doi  openurl
  Title Factors affecting information transfer from knowledgeable to naive individuals in groups Type Journal Article
  Year 2008 Publication Behavioral Ecology and Sociobiology Abbreviated Journal Behav. Ecol. Sociobiol.  
  Volume 63 Issue 2 Pages 159-171-171  
  Keywords Biomedical and Life Sciences  
  Abstract There is evidence that individuals in animal groups benefit from the presence of knowledgeable group members in different ways. Experiments and computer simulations have shown that a few individuals within a group can lead others, for a precise task and at a specific moment. As a group travels, different individuals possessing a particular knowledge may act as temporary leaders, so that the group will, as a whole, follow their behaviour. In this paper, we use a model to study different factors influencing group response to temporary leadership. The model is based on four individual behaviours. Three of those, attraction, repulsion, and alignment, are shared by all individuals. The last one, attraction toward the source of a stimulus, concerns only a fraction of the group members. We explore the influence of group size, proportion of stimulated individuals, number of influential neighbours, and intensity of the attraction to the source of the stimulus, on the proportion of the group reaching this source. Special attention is given to the simulation of large group size, close to those observed in nature. Groups of 100, 400 and 900 individuals are currently simulated, and up to 8,000 in one experiment. We show that more stimulated individuals and a larger group size both induce the arrival of a larger fraction of the group. The number of influential neighbours and the intensity of the stimulus have a non-linear influence on the proportion of the group arrival, displaying first a positive relationship and then, above a given threshold, a negative one. We conclude that an intermediate level of group cohesion provides optimal transfer information from knowledgeable to naive individuals.  
  Address  
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  Publisher Springer Berlin / Heidelberg Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0340-5443 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5295  
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Author Schwab, C.; Bugnyar, T.; Schloegl, C.; Kotrschal, K. url  doi
openurl 
  Title Enhanced social learning between siblings in common ravens, Corvus corax Type Journal Article
  Year 2008 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 75 Issue 2 Pages 501-508  
  Keywords affiliation; cognition; common raven; Corvus corax; siblings; social learning; social relations  
  Abstract It has been suggested that social dynamics affect social learning but empirical support for this idea is scarce. Here we show that affiliate relationships among kin indeed enhance the performance of common ravens, Corvus corax, in a social learning task. Via daily behavioural protocols we first monitored social dynamics in our group of captive young ravens. Siblings spent significantly more time in close proximity to each other than did nonsiblings. We subsequently tested birds on a stimulus enhancement task in model-observer dyads composed of both siblings and nonsiblings. During demonstration the observer could watch the model manipulating one particular object (target object) in an adjacent room. After removing the model, the observer was confronted with five different objects including the former target object. Observers from sibling dyads handled the target object for significantly longer periods of time as compared with the other four available objects, whereas observers from nonsibling dyads did not show a preference for the target object. Also, siblings matched the model's decision to cache or not to cache objects significantly more often than did nonsiblings. Hence, siblings were likely to attend to both, the behaviour of the model (caching or noncaching) and object-specific details. Our results support the hypothesis that affiliate relations between individuals affect the transmission of information and may lead to directed social learning even when spatial proximity has been experimentally controlled for.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-3472 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5300  
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