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Author Conradt, L.; Roper, T.J.
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
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:12520299 Approved no
Call Number Equine Behaviour @ team @ Serial 5136
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Author Seyfarth, R.M.
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 (up) 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.
Address
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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 Gonzalez-Fernandez, J.M.; Atta, S.E.
Title Facilitated transport of oxygen in the presence of membranes in the diffusion path Type Journal Article
Year 1982 Publication Biophysical Journal Abbreviated Journal Biophys J
Volume 38 Issue 2 Pages 133-141
Keywords (up) Animals; Biological Transport, Active; Cell Membrane/*metabolism; Diffusion; Dogs; Horses; Humans; Kinetics; Mathematics; *Models, Biological; Muscles/*metabolism; Oxygen/*metabolism
Abstract Most of the experimental observations on facilitated transport have been done with millipore filters, and all the theoretical studies have assumed homogeneous spatial properties. In striated muscle there exist membranes that may impede the diffusion of the carrier myoglobin. In this paper a theoretical study is undertaken to analyze the transport in the presence of membranes in the diffusion path. For the numerical computations physiologically relevant values of the parameters were chosen. The numerical results indicate that the presence of membranes tends to decrease the facilitation. For the nonlinear chemical kinetics of the reaction of oxygen with the carrier, this decrement also depends on the location of the membranes. At the higher oxygen concentration side of each membrane the flow of combined oxygen is transferred to the flow of dissolved oxygen. The reverse process occurs at the lower concentration side. Jump discontinuities of the concentration of the oxygen-carrier compound at each membrane are associated with these transfers. The decrement of facilitation is due to the cumulative effect of these jump discontinuities.
Address
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 0006-3495 ISBN Medium
Area Expedition Conference
Notes PMID:7093418 Approved no
Call Number Equine Behaviour @ team @ Serial 3806
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Author Izar, P.; Ferreira, R.G.; Sato, T.
Title Describing the organization of dominance relationships by dominance-directed tree method Type Journal Article
Year 2006 Publication American journal of primatology Abbreviated Journal Am. J. Primatol.
Volume 68 Issue 2 Pages 189-207
Keywords (up) Animals; Cebus/physiology; *Models, Biological; *Social Dominance
Abstract Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed “dominance-directed tree.” This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella.
Address Department of Experimental Psychology, University of Sao Paulo, Brazil. patrizar@usp.br
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 0275-2565 ISBN Medium
Area Expedition Conference
Notes PMID:16429416 Approved no
Call Number refbase @ user @ Serial 723
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Author Dubois, F.; Giraldeau, L.-A.
Title The forager's dilemma: food sharing and food defense as risk-sensitive foraging options Type Journal Article
Year 2003 Publication The American Naturalist Abbreviated Journal Am Nat
Volume 162 Issue 6 Pages 768-779
Keywords (up) Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics
Abstract Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-0147 ISBN Medium
Area Expedition Conference
Notes PMID:14737714 Approved no
Call Number Serial 2132
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Author Zhou, W.-X.; Sornette, D.; Hill, R.A.; Dunbar, R.I.M.
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 (up) 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
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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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