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Author Seyfarth, R.M. url  doi
openurl 
  Title A model of social grooming among adult female monkeys Type Journal Article
  Year 1977 Publication Journal of Theoretical Biology Abbreviated Journal J. Theor. Biol.  
  Volume 65 Issue 4 Pages 671-698  
  Keywords Animals; Behavior, Animal; Female; *Grooming; Haplorhini/*physiology; *Models, Biological; Reproduction; Social Dominance; Time Factors  
  Abstract Grooming networks among adult female monkeys exhibit two similar features across a number of different species. High-ranking animals receive more grooming than others, and the majority of grooming occurs between females of adjacent rank. A theoretical model which duplicates these features is presented, and the properties of the model are used to explain the possible causation and function of female grooming behaviour. The model illustrates how relatively simple principles governing the behaviour of individuals may be used to explain more complex aspects of the social structure of non-human primate groups.  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-5193 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:406485 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5259  
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Author Harcourt, J.L.; Ang, T.Z.; Sweetman, G.; Johnstone, R.A.; Manica, A. url  doi
openurl 
  Title Social feedback and the emergence of leaders and followers Type Journal Article
  Year 2009 Publication Current Biology : CB Abbreviated Journal Curr Biol  
  Volume 19 Issue 3 Pages 248-252  
  Keywords Analysis of Variance; Animals; Appetitive Behavior/physiology; *Feedback; Great Britain; *Leadership; Markov Chains; Models, Biological; Monte Carlo Method; Smegmamorpha/*physiology; *Social Behavior; Video Recording  
  Abstract In many animal groups, certain individuals consistently appear at the forefront of coordinated movements [1-4]. How such leaders emerge is poorly understood [5, 6]. Here, we show that in pairs of sticklebacks, Gasterosteus aculeatus, leadership arises from individual differences in the way that fish respond to their partner's movements. Having first established that individuals differed in their propensity to leave cover in order to look for food, we randomly paired fish of varying boldness, and we used a Markov Chain model to infer the individual rules underlying their joint behavior. Both fish in a pair responded to each other's movements-each was more likely to leave cover if the other was already out and to return if the other had already returned. However, we found that bolder individuals displayed greater initiative and were less responsive to their partners, whereas shyer individuals displayed less initiative but followed their partners more faithfully; they also, as followers, elicited greater leadership tendencies in their bold partners. We conclude that leadership in this case is reinforced by positive social feedback.  
  Address Department of Zoology, University of Cambridge, Cambridge, UK  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0960-9822 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19185497 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5123  
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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. url  doi
openurl 
  Title The emergence of leaders and followers in foraging pairs when the qualities of individuals differ Type Journal Article
  Year 2008 Publication BMC Evolutionary Biology Abbreviated Journal BMC Evol Biol  
  Volume 8 Issue Pages 51  
  Keywords Animals; *Feeding Behavior; *Food Chain; *Models, Biological; *Social Dominance  
  Abstract BACKGROUND: Foraging in groups offers animals a number of advantages, such as increasing their likelihood of finding food or detecting and avoiding predators. In order for a group to remain together, there has to be some degree of coordination of behaviour and movement between its members (which may in some cases be initiated by a decision-making leader, and in other cases may emerge as an underlying property of the group). For example, behavioural synchronisation is a phenomenon where animals within a group initiate and then continue to conduct identical behaviours, and has been characterised for a wide range of species. We examine how a pair of animals should behave using a state-dependent approach, and ask what conditions are likely to lead to behavioural synchronisation occurring, and whether one of the individuals is more likely to act as a leader. RESULTS: The model we describe considers how the energetic gain, metabolic requirements and predation risks faced by the individuals affect measures of their energetic state and behaviour (such as the degree of behavioural synchronisation seen within the pair, and the value to an individual of knowing the energetic state of its colleague). We explore how predictable changes in these measures are in response to changes in physiological requirements and predation risk. We also consider how these measures should change when the members of the pair are not identical in their metabolic requirements or their susceptibility to predation. We find that many of the changes seen in these measures are complex, especially when asymmetries exist between the members of the pair. CONCLUSION: Analyses are presented that demonstrate that, although these general patterns are robust, care needs to be taken when considering the effects of individual differences, as the relationship between individual differences and the resulting qualitative changes in behaviour may be complex. We discuss how these results are related to experimental observations, and how the model and its predictions could be extended.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. sean.rands@bristol.ac.uk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1471-2148 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:18282297 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5126  
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Author Vallortigara, G.; Rogers, L.J. url  doi
openurl 
  Title Survival with an asymmetrical brain: advantages and disadvantages of cerebral lateralization Type Journal Article
  Year 2005 Publication The Behavioral and Brain Sciences Abbreviated Journal Behav Brain Sci  
  Volume 28 Issue 4 Pages 575-89; discussion 589-633  
  Keywords Animals; Attention/*physiology; Behavior/*physiology; Behavior, Animal/*physiology; Dominance, Cerebral/*physiology; *Evolution; Humans; Models, Biological; Visual Perception/physiology  
  Abstract Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal's left or right at random; there is no a priori association between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal's left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from population-level lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an “evolutionarily stable strategy” under “social” pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species.  
  Address Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, 34123 Trieste, Italy. vallorti@univ.trieste.it  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0140-525X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16209828 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4622  
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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. url  doi
openurl 
  Title Spontaneous emergence of leaders and followers in foraging pairs Type Journal Article
  Year 2003 Publication Nature Abbreviated Journal Nature  
  Volume 423 Issue 6938 Pages 432-434  
  Keywords Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors  
  Abstract Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk  
  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 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12761547 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5138  
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Author Conradt, L.; Roper, T.J. url  doi
openurl 
  Title Group decision-making in animals Type Journal Article
  Year 2003 Publication Nature Abbreviated Journal Nature  
  Volume 421 Issue 6919 Pages 155-158  
  Keywords Animals; Behavior, Animal/*physiology; *Decision Making; Democracy; Group Processes; *Models, Biological; Population Density; Social Behavior  
  Abstract Groups of animals often need to make communal decisions, for example about which activities to perform, when to perform them and which direction to travel in; however, little is known about how they do so. Here, we model the fitness consequences of two possible decision-making mechanisms: 'despotism' and 'democracy'. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans.  
  Address School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK. l.conradt@sussex.ac.uk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12520299 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5136  
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Author Biro, D.; Sumpter, D.J.T.; Meade, J.; Guilford, T. url  doi
openurl 
  Title From Compromise to Leadership in Pigeon Homing Type Journal Article
  Year 2006 Publication Current Biology Abbreviated Journal Curr Biol  
  Volume 16 Issue 21 Pages 2123-2128  
  Keywords Animal Migration; Animals; Columbidae/*physiology; Decision Making; *Flight, Animal; *Homing Behavior; Models, Biological; Orientation; *Social Behavior; *Social Dominance  
  Abstract Summary A central problem faced by animals traveling in groups is how navigational decisions by group members are integrated, especially when members cannot assess which individuals are best informed or have conflicting information or interests , , , and . Pigeons are now known to recapitulate faithfully their individually distinct habitual routes home , and , and this provides a novel paradigm for investigating collective decisions during flight under varying levels of interindividual conflict. Using high-precision GPS tracking of pairs of pigeons, we found that if conflict between two birds' directional preferences was small, individuals averaged their routes, whereas if conflict rose over a critical threshold, either the pair split or one of the birds became the leader. Modeling such paired decision-making showed that both outcomes--compromise and leadership--could emerge from the same set of simple behavioral rules. Pairs also navigated more efficiently than did the individuals of which they were composed, even though leadership was not necessarily assumed by the more efficient bird. In the context of mass migration of birds and other animals, our results imply that simple self-organizing rules can produce behaviors that improve accuracy in decision-making and thus benefit individuals traveling in groups , and .  
  Address Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom. daro.biro@zoo.ox.ac.uk  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Englisch Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0960-9822 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17084696 Approved no  
  Call Number Serial 2026  
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Author Zhou, W.-X.; Sornette, D.; Hill, R.A.; Dunbar, R.I.M. doi  openurl
  Title Discrete hierarchical organization of social group sizes Type Journal Article
  Year 2005 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 272 Issue 1561 Pages 439-444  
  Keywords Anthropology, Cultural; *Group Structure; Humans; *Models, Biological; *Social Behavior; *Social Environment  
  Abstract The 'social brain hypothesis' for the evolution of large brains in primates has led to evidence for the coevolution of neocortical size and social group sizes, suggesting that there is a cognitive constraint on group size that depends, in some way, on the volume of neural material available for processing and synthesizing information on social relationships. More recently, work on both human and non-human primates has suggested that social groups are often hierarchically structured. We combine data on human grouping patterns in a comprehensive and systematic study. Using fractal analysis, we identify, with high statistical confidence, a discrete hierarchy of group sizes with a preferred scaling ratio close to three: rather than a single or a continuous spectrum of group sizes, humans spontaneously form groups of preferred sizes organized in a geometrical series approximating 3-5, 9-15, 30-45, etc. Such discrete scale invariance could be related to that identified in signatures of herding behaviour in financial markets and might reflect a hierarchical processing of social nearness by human brains.  
  Address State Key Laboratory of Chemical Reaction Engineering, East China University of Science and Technology, Shanghai 200237, China  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15734699 Approved no  
  Call Number refbase @ user @ Serial 549  
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Author Cameron, E.Z. doi  openurl
  Title Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism Type Journal Article
  Year 2004 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 271 Issue 1549 Pages 1723-1728  
  Keywords Age Factors; Animals; Body Constitution; *Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/*physiology; *Models, Biological; Reproduction/physiology; Seasons; Sex Factors; *Sex Ratio; Time Factors  
  Abstract Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.  
  Address Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15306293 Approved no  
  Call Number refbase @ user @ Serial 413  
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Author Brilot, B.O.; Johnstone, R.A. doi  openurl
  Title The limits to cost-free signalling of need between relatives Type Journal Article
  Year 2003 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 270 Issue 1519 Pages 1055-1060  
  Keywords *Animal Communication; Animals; Birds/physiology; Models, Biological; *Social Behavior  
  Abstract Theoretical models have demonstrated the possibility of stable cost-free signalling of need between relatives. The stability of these cost-free equilibria depends on the indirect fitness cost of cheating and deceiving a donor into giving away resources. We show that this stability is highly sensitive to the distribution of need among signallers and receivers. In particular, cost-free signalling is likely to prove stable only if there is very large variation in need (such that the least-needy individuals stand to gain much less than the most-needy individuals from additional resources). We discuss whether these conditions are likely to be found in altricial avian breeding systems--the most intensively studied instance of signalling of need between relatives. We suggest that cost-free signalling is more likely to prove stable and will provide parents with more information during the earlier phases of chick growth, when parents can more easily meet the demands of a brood (and chicks are more likely to reach satiation). Later, informative yet cost-free signalling is unlikely to persist.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. bob21@cam.ac.uk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12803895 Approved no  
  Call Number refbase @ user @ Serial 558  
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