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Author Viscido, S.V.; Miller, M.; Wethey, D.S. openurl 
  Title The dilemma of the selfish herd: the search for a realistic movement rule Type Journal Article
  Year 2002 Publication Journal of theoretical biology Abbreviated Journal J. Theor. Biol.  
  Volume 217 Issue 2 Pages 183-194  
  Keywords (up) Animals; *Behavior, Animal; *Mass Behavior; Models, Biological; *Motor Activity; Predatory Behavior  
  Abstract The selfish herd hypothesis predicts that aggregations form because individuals move toward one another to minimize their own predation risk. The “dilemma of the selfish herd” is that movement rules that are easy for individuals to follow, fail to produce true aggregations, while rules that produce aggregations require individual behavior so complex that one may doubt most animals can follow them. If natural selection at the individual level is responsible for herding behavior, a solution to the dilemma must exist. Using computer simulations, we examined four different movement rules. Relative predation risk was different for all four movement rules (p<0.05). We defined three criteria for measuring the quality of a movement rule. A good movement rule should (a) be statistically likely to benefit an individual that follows it, (b) be something we can imagine most animals are capable of following, and (c) result in a centrally compact flock. The local crowded horizon rule, which allowed individuals to take the positions of many flock-mates into account, but decreased the influence of flock-mates with distance, best satisfied these criteria. The local crowded horizon rule was very sensitive to the animal's perceptive ability. Therefore, the animal's ability to detect its neighbors is an important factor in the dynamics of group formation.  
  Address Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA. viscido@u.washington.edu  
  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 0022-5193 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12202112 Approved no  
  Call Number refbase @ user @ Serial 554  
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Author Flack, J.C.; de Waal, F.B.M.; Krakauer, D.C. doi  openurl
  Title Social structure, robustness, and policing cost in a cognitively sophisticated species Type Journal Article
  Year 2005 Publication The American Naturalist Abbreviated Journal Am Nat  
  Volume 165 Issue 5 Pages E126-139  
  Keywords (up) Animals; *Behavior, Animal; Cognition; Conflict (Psychology); Female; Macaca nemestrina/*physiology; Male; Models, Biological; *Social Behavior  
  Abstract Conflict management is one of the primary requirements for social complexity. Of the many forms of conflict management, one of the rarest and most interesting is third-party policing, or intervening impartially to control conflict. Third-party policing should be hard to evolve because policers personally pay a cost for intervening, while the benefits are diffused over the whole group. In this study we investigate the incidence and costs of policing in a primate society. We report quantitative evidence of non-kin policing in the nonhuman primate, the pigtailed macaque. We find that policing is effective at reducing the intensity of or terminating conflict when performed by the most powerful individuals. We define a measure, social power consensus, that predicts effective low-cost interventions by powerful individuals and ineffective, relatively costly interventions by low-power individuals. Finally, we develop a simple probabilistic model to explore whether the degree to which policing can effectively reduce the societal cost of conflict is dependent on variance in the distribution of power. Our data and simple model suggest that third-party policing effectiveness and cost are dependent on power structure and might emerge only in societies with high variance in power.  
  Address Santa Fe Institute, Santa Fe, New Mexico 87501, USA. jflack@santafe.edu  
  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 1537-5323 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15795848 Approved no  
  Call Number refbase @ user @ Serial 168  
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Author Kaplan, A.I.; Borodovskii, M.I. openurl 
  Title [Alternative animal behavior: a model and its statistical characteristics] Type Journal Article
  Year 1989 Publication Nauchnye Doklady Vysshei Shkoly. Biologicheskie Nauki Abbreviated Journal Nauchnye Doki Vyss Shkoly Biol Nauki  
  Volume Issue 3 Pages 29-32  
  Keywords (up) Animals; *Behavior, Animal; Cognition; Male; Mathematics; *Models, Biological; *Models, Statistical; Rats; Reinforcement (Psychology)  
  Abstract The rats' alternative behaviour in T-maze at simultaneous two-sided food refreshment in 13 trials a day during 6 days has been studied. It has been found that in the first testing days the indexes of alternative behaviour of animals correspond to the characteristics of the random alternation. However, on the 5-6th day of testing in the overwhelming majority of rats the true deviation of alternation index above or below than the theoretical values has been revealed. A question on the existence of two strategies of cognitive behaviour alteration and perseveration in rat population is under discussion.  
  Address  
  Corporate Author Thesis  
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  Language Russian Summary Language Original Title Al'ternativnoe povedenie zhivotnykh: model' i statisticheskie kharakteristiki  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0470-4606 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:2742929 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2799  
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Author Scheffer, M.; van Nes, E.H. doi  openurl
  Title Self-organized similarity, the evolutionary emergence of groups of similar species Type Journal Article
  Year 2006 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 103 Issue 16 Pages 6230-6235  
  Keywords (up) Animals; *Competitive Behavior; *Ecosystem; *Evolution; *Models, Biological  
  Abstract Ecologists have long been puzzled by the fact that there are so many similar species in nature. Here we show that self-organized clusters of look-a-likes may emerge spontaneously from coevolution of competitors. The explanation is that there are two alternative ways to survive together: being sufficiently different or being sufficiently similar. Using a model based on classical competition theory, we demonstrate a tendency for evolutionary emergence of regularly spaced lumps of similar species along a niche axis. Indeed, such lumpy patterns are commonly observed in size distributions of organisms ranging from algae, zooplankton, and beetles to birds and mammals, and could not be well explained by earlier theory. Our results suggest that these patterns may represent self-constructed niches emerging from competitive interactions. A corollary of our findings is that, whereas in species-poor communities sympatric speciation and invasion of open niches is possible, species-saturated communities may be characterized by convergent evolution and invasion by look-a-likes.  
  Address Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 8080, 6700 DD, Wageningen, The Netherlands. marten.scheffer@wur.nl  
  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 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16585519 Approved no  
  Call Number refbase @ user @ Serial 510  
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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 (up) 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  
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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:12761547 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5138  
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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 (up) 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 Hamilton, W.D. doi  openurl
  Title Geometry for the selfish herd Type Journal Article
  Year 1971 Publication Journal of theoretical biology Abbreviated Journal J. Theor. Biol.  
  Volume 31 Issue 2 Pages 295-311  
  Keywords (up) Animals; Anura; *Behavior, Animal; Breeding; Communication; Evolution; Fear; Metallurgy; *Models, Biological; Probability; Snakes; *Spatial Behavior  
  Abstract This paper presents an antithesis to the view that gregarious behaviour is evolved through benefits to the population or species. Following Galton (1871) and Williams (1964) gregarious behaviour is considered as a form of cover-seeking in which each animal tries to reduce its chance of being caught by a predator.

It is easy to see how pruning of marginal individuals can maintain centripetal instincts in already gregarious species; some evidence that marginal pruning actually occurs is summarized. Besides this, simply defined models are used to show that even in non-gregarious species selection is likely to favour individuals who stay close to others.

Although not universal or unipotent, cover-seeking is a widespread and important element in animal aggregation, as the literature shows. Neglect of the idea has probably followed from a general disbelief that evolution can be dysgenic for a species. Nevertheless, selection theory provides no support for such disbelief in the case of species with outbreeding or unsubdivided populations.

The model for two dimensions involves a complex problem in geometrical probability which has relevance also in metallurgy and communication science. Some empirical data on this, gathered from random number plots, is presented as of possible heuristic value.
 
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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:5104951 Approved no  
  Call Number refbase @ user @ Serial 771  
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Author Munoz-Sanz, A. openurl 
  Title [Christopher Columbus flu. A hypothesis for an ecological catastrophe] Type Journal Article
  Year 2006 Publication Enfermedades Infecciosas y Microbiologia Clinica Abbreviated Journal Enferm Infecc Microbiol Clin  
  Volume 24 Issue 5 Pages 326-334  
  Keywords (up) Animals; Atlantic Islands; Birds; Chickens; Disease Outbreaks/*history; Disease Reservoirs; Disease Susceptibility; Ecology; Europe/ethnology; History, 15th Century; Horses; Humans; Indians, South American; Influenza A virus/classification/genetics/pathogenicity; Influenza in Birds/epidemiology/history/transmission/virology; Influenza, Human/epidemiology/*history/mortality/transmission; Models, Biological; Orthomyxoviridae Infections/epidemiology/history/veterinary/virology; Poultry Diseases/epidemiology/history/transmission/virology; Reassortant Viruses/genetics/pathogenicity; Species Specificity; Sus scrofa; Swine Diseases/history/transmission/virology; Terminology; West Indies/epidemiology  
  Abstract When Christopher Columbus and his men embarked on the second Colombian expedition to the New World (1493), the crew suffered from fever, respiratory symptoms and malaise. It is generally accepted that the disease was influenza. Pigs, horses and hens acquired in Gomera (Canary Islands) traveled in the same ship. The pigs may well have been the origin of the flu and the intermediary hosts for genetic recombination of other viral subtypes. The Caribbean archipelago had a large population of birds, the natural reservoir of the avian influenza virus. In this ecological scenario there was a concurrence of several biological elements that had never before coexisted in the New World: pigs, horses, the influenza virus and humans. We propose that birds are likely to have played an important role in the epidemiology of the flu occurring on the second Colombian trip, which caused a fatal demographic catastrophe, with an estimated mortality of 90% among the natives.  
  Address Unidad de Patologia Infecciosa, Hospital Universitario Infanta Cristina, Servicio Extremeno de Salud, Universidad de Extremadura, Badajoz, Espana. infectio@unex.es  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Spanish Summary Language Original Title La gripe de Cristobal Colon. Hipotesis sobre una catastrofe ecologica  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0213-005X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16762260 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2624  
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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 (up) 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  
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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 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 (up) 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  
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  Language English Summary Language Original Title  
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  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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