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Vanesse N, Opsomer E, Lumay G, Vandewalle N. Collective dynamics of dipolar self-propelled particles. Phys Rev E 2023; 108:024608. [PMID: 37723805 DOI: 10.1103/physreve.108.024608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/13/2023] [Indexed: 09/20/2023]
Abstract
We present a numerical study of the collective behavior of self-propelled particles for which dipolar interactions are considered. These are obtained by introducing pointlike magnetic dipoles in the particles. Various dynamical regimes are found depending on three major parameters: the density of particles, the ratio Γ defined as the competition between kinetic energy and potential magnetic energy, as well as the orientation of the magnetic dipoles inherent to the particles. Patterns such as chains, vortices, flocks, and strips have been obtained.
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Affiliation(s)
- N Vanesse
- GRASP, Institute of Physics B5a, University of Liège, 4000 Liège, Belgium
| | - E Opsomer
- GRASP, Institute of Physics B5a, University of Liège, 4000 Liège, Belgium
| | - G Lumay
- GRASP, Institute of Physics B5a, University of Liège, 4000 Liège, Belgium
| | - N Vandewalle
- GRASP, Institute of Physics B5a, University of Liège, 4000 Liège, Belgium
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2
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van Haeringen E, Hemelrijk C. Hierarchical development of dominance through the winner-loser effect and socio-spatial structure. PLoS One 2022; 17:e0243877. [PMID: 35108262 PMCID: PMC8809560 DOI: 10.1371/journal.pone.0243877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/04/2022] [Indexed: 11/25/2022] Open
Abstract
In many groups of animals the dominance hierarchy is linear. What mechanisms underlie this linearity of the dominance hierarchy is under debate. Linearity is often attributed to cognitively sophisticated processes, such as transitive inference and eavesdropping. An alternative explanation is that it develops via the winner-loser effect. This effect implies that after a fight has been decided the winner is more likely to win again, and the loser is more likely to lose again. Although it has been shown that dominance hierarchies may develop via the winner-loser effect, the degree of linearity of such hierarchies is unknown. The aim of the present study is to investigate whether a similar degree of linearity, like in real animals, may emerge as a consequence of the winner-loser effect and the socio-spatial structure of group members. For this purpose, we use the model DomWorld, in which agents group and compete and the outcome of conflicts is self-reinforcing. Here dominance hierarchies are shown to emerge. We analyse the dominance hierarchy, behavioural dynamics and network triad motifs in the model using analytical methods from a previous study on dominance in real hens. We show that when one parameter, representing the intensity of aggression, was set high in the model DomWorld, it reproduced many patterns of hierarchical development typical of groups of hens, such as its high linearity. When omitting from the model the winner-loser effect or spatial location of individuals, this resemblance decreased markedly. We conclude that the combination of the spatial structure and the winner-loser effect provide a plausible alternative for hierarchical linearity to processes that are cognitively more sophisticated. Further research should determine whether the winner-loser effect and spatial structure of group members also explains the characteristics of hierarchical development in other species with a different dominance style than hens.
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Affiliation(s)
- Erik van Haeringen
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- * E-mail:
| | - Charlotte Hemelrijk
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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3
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Planas-Sitjà I, Deneubourg JL, Cronin AL. Variation in personality can substitute for social feedback in coordinated animal movements. Commun Biol 2021; 4:469. [PMID: 33850250 PMCID: PMC8044162 DOI: 10.1038/s42003-021-01991-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 03/11/2021] [Indexed: 12/12/2022] Open
Abstract
Collective movements are essential for the effective function of animal societies, but are complicated by the need for consensus among group members. Consensus is typically assumed to arise via feedback mechanisms, but this ignores inter-individual variation in behavioural tendency ('personality'), which is known to underpin the successful function of many complex societies. In this study, we use a theoretical approach to examine the relative importance of personality and feedback in the emergence of collective movement decisions in animal groups. Our results show that variation in personality dramatically influences collective decisions and can partially or completely replace feedback depending on the directionality of relationships among individuals. The influence of personality increases with the exaggeration of differences among individuals. While it is likely that both feedback and personality interact in nature, our findings highlight the potential importance of personality in driving collective processes.
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Affiliation(s)
| | - Jean-Louis Deneubourg
- Center of Nonlinear Phenomena and Complex Systems (CENOLI) - CP 231, Université libre de Bruxelles, Bruxelles, Belgium
| | - Adam L Cronin
- Department of Biology, Tokyo Metropolitan University, Tokyo, Japan
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4
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Loftus JC, Perez AA, Sih A. Task syndromes: linking personality and task allocation in social animal groups. Behav Ecol 2021; 32:1-17. [PMID: 33708004 PMCID: PMC7937036 DOI: 10.1093/beheco/araa083] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 08/04/2020] [Accepted: 08/07/2020] [Indexed: 11/12/2022] Open
Abstract
Studies of eusocial insects have extensively investigated two components of task allocation: how individuals distribute themselves among different tasks in a colony and how the distribution of labor changes to meet fluctuating task demand. While discrete age- and morphologically-based task allocation systems explain much of the social order in these colonies, the basis for task allocation in non-eusocial organisms and within eusocial castes remains unknown. Building from recent advances in the study of among-individual variation in behavior (i.e., animal personalities), we explore a potential mechanism by which individuality in behaviors unrelated to tasks can guide the developmental trajectories that lead to task specialization. We refer to the task-based behavioral syndrome that results from the correlation between the antecedent behavioral tendencies and task participation as a task syndrome. In this review, we present a framework that integrates concepts from a long history of task allocation research in eusocial organisms with recent findings from animal personality research to elucidate how task syndromes and resulting task allocation might manifest in animal groups. By drawing upon an extensive and diverse literature to evaluate the hypothesized framework, this review identifies future areas for study at the intersection of social behavior and animal personality.
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Affiliation(s)
- J C Loftus
- Department of Anthropology, University of California at Davis, Davis, CA, USA.,Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Radolfzell, Germany.,Department of Biology, University of Konstanz, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - A A Perez
- Department of Entomology, University of California at Davis, Davis, CA, USA
| | - A Sih
- Department of Environmental Science and Policy, University of California at Davis, Davis, CA, USA
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Planas-Sitjà I. Personality variation improves collective decision-making in cockroaches. Behav Processes 2020; 177:104147. [PMID: 32454182 DOI: 10.1016/j.beproc.2020.104147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 11/16/2022]
Abstract
Many animals live in groups and engage in collective actions which can enhance their fitness. One common example is collective decision-making, which mainly arises from social interactions that modify the individual behaviour. Despite the widespread interest in animal personalities on the one hand and in social effects (such as social organisation, social learning or anti-predator behaviour) on the other, the question of how the amount of among-individual differences, coupled with social interactions, influence group cohesion has rarely been addressed. For this purpose, I used a modelling approach based on aggregation behaviour of cockroaches to explore the mechanisms underlying such context-dependent behaviour. The results of simulations considering different degrees (none, medium, high) of personality variation in a non-social and social context were compared to experimental patterns of aggregation dynamics in cockroaches. The comparison between the simulated and experimental data show that only a model that considers differences in individuals was able to reproduce the experimental patterns of individuals and groups. In addition, the comparison between models suggest that some individuals may play a keystone role during aggregation dynamics, influencing the behaviour of others and facilitating the collective decision. Finally, I show that personality variation amplifies the effects of social inter-attractions, thus increasing the speed of aggregation, shedding light on the mechanisms underpinning social modification of individual behaviour.
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Affiliation(s)
- Isaac Planas-Sitjà
- Systematic Zoology Laboratory, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
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6
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Härkönen L, Alioravainen N, Vainikka A, Hyvärinen P. Night reveals individuality in a shoaling fish. Behav Ecol 2019. [DOI: 10.1093/beheco/arz015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Laura Härkönen
- Department of Ecology and Genetics, University of Oulu, Pentti Kaiteran katu, Oulu, Finland
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
- Aquatic population dynamics, Natural Resources Institute Finland (Luke), Paavo Havaksen tie, Oulu, Finland
| | - Nico Alioravainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Anssi Vainikka
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Pekka Hyvärinen
- Aquatic population dynamics, Kainuu Fisheries Research Station, Natural Resources Institute Finland (Luke), Manamansalontie,Paltamo, Finland
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Canario L, Lundeheim N, Bijma P. The early-life environment of a pig shapes the phenotypes of its social partners in adulthood. Heredity (Edinb) 2017; 118:534-541. [PMID: 28327581 PMCID: PMC5436026 DOI: 10.1038/hdy.2017.3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/16/2016] [Accepted: 12/22/2016] [Indexed: 11/08/2022] Open
Abstract
Social interactions among individuals are abundant, both in natural and domestic populations, and may affect phenotypes of individuals. Recent research has demonstrated that the social effect of an individual on the phenotype of its social partners may have a genetic component, known as an indirect genetic effect (IGE). Little is known, however, of nongenetic factors underlying such social effects. Early-life environments often have large effects on phenotypes of the individuals themselves later in life. Offspring development in many mammalian species, for example, depends on interactions with the mother and siblings. In domestic pigs, individuals sharing the same juvenile environment develop similar body weight later in life. We, therefore, hypothesized that offspring originating from the same early-life environment also develop common social skills that generate early-life social effects (ELSEs) that affect the phenotypes of their social partners later in life. We, therefore, quantified IGEs and ELSEs on growth in domestic pigs. Results show that individuals from the same early-life environment express similar social effects on the growth of their social partners, and that such ELSEs shape the growth rate of social partners more than IGEs. Thus, the social skills that individuals develop in early life have a long-lasting impact on the phenotypes of social partners. Early-life and genetic social effects were independent of the corresponding direct effects of offspring on their own growth, indicating that individuals may enhance the growth of their social partners without a personal cost. Our findings also illustrate how research devoted to quantifying IGEs may miss nongenetic and potentially confounded social mechanisms which may bias the estimates of IGEs.
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Affiliation(s)
- L Canario
- Department of Animal Genetics, INRA French National Institute for Agricultural Research, Castanet-Tolosan, France
| | - N Lundeheim
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - P Bijma
- Animal Breeding and Genomics Centre, Wageningen University and Research, Wageningen, The Netherlands
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8
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Belgrad BA, Griffen BD. Habitat quality mediates personality through differences in social context. Oecologia 2017; 184:431-440. [PMID: 28528392 DOI: 10.1007/s00442-017-3886-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 05/15/2017] [Indexed: 10/19/2022]
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9
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The Self-organization of Social Complexity in Group-Living Animals. ADVANCES IN THE STUDY OF BEHAVIOR 2017. [DOI: 10.1016/bs.asb.2017.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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10
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Snijders L, Naguib M. Communication in Animal Social Networks. ADVANCES IN THE STUDY OF BEHAVIOR 2017. [DOI: 10.1016/bs.asb.2017.02.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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11
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12
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King AJ, Williams LJ, Mettke-Hofmann C. The effects of social conformity on Gouldian finch personality. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.10.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Kekäläinen J, Podgorniak T, Puolakka T, Hyvärinen P, Vainikka A. Individually assessed boldness predicts Perca fluviatilis behaviour in shoals, but is not associated with the capture order or angling method. JOURNAL OF FISH BIOLOGY 2014; 85:1603-1616. [PMID: 25270290 DOI: 10.1111/jfb.12516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/26/2014] [Indexed: 06/03/2023]
Abstract
Selectivity of recreational angling on fish behaviour was studied by examining whether capture order or lure type (natural v. artificial bait) in ice-fishing could explain behavioural variation among perch Perca fluviatilis individuals. It was also tested if individually assessed personality predicts fish behaviour in groups, in the presence of natural predators. Perca fluviatilis showed individually repeatable behaviour both in individual and in group tests. Capture order, capture method, condition factor or past growth rate did not explain variation in individual behaviour. Individually determined boldness as well as fish size, however, were positively associated with first entrance to the predator zone (i.e. initial risk taking) in group behaviour tests. Individually determined boldness also explained long-term activity and total time spent in the vicinity of predators in the group. These findings suggest that individual and laboratory-based boldness tests predict boldness of P. fluviatilis in also ecologically relevant conditions, i.e. in shoals and in the presence of natural predators. The present results, however, also indicate that the above-mentioned two angling methods may not be selective for certain behavioural types in comparison to each other.
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Affiliation(s)
- J Kekäläinen
- Department of Biology, University of Eastern Finland, P. O. Box 111, FI 80101 Joensuu, Finland; School of Animal Biology, Centre for Evolutionary Biology, University of Western Australia, Crawley, WA 6009, Australia
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14
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Thierry B. Identifying constraints in the evolution of primate societies. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120342. [PMID: 23569290 PMCID: PMC3638445 DOI: 10.1098/rstb.2012.0342] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The evolutionary study of social systems in non-human primates has long been focused on ecological determinants. The predictive value of socio-ecological models remains quite low, however, in particular because such equilibrium models cannot integrate the course of history. The use of phylogenetic methods indicates that many patterns of primate societies have been conserved throughout evolutionary history. For example, the study of social relations in macaques revealed that their social systems are made of sets of correlated behavioural traits. Some macaque species are portrayed by marked social intolerance, a steep dominance gradient and strong nepotism, whereas others display a higher level of social tolerance, relaxed dominance and a weaker influence of kinship. Linkages between behavioural traits occur at different levels of organization, and act as constraints that limit evolutionary responses to external pressures. Whereas these constraints can exert strong stabilizing selection that opposes the potential changes required by the ecological environment, selective mechanisms may have the potential to switch the whole social system from one state to another by acting primarily on some key behavioural traits that could work as pacemakers.
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Affiliation(s)
- Bernard Thierry
- Centre National de la Recherche Scientifique, Département Ecologie, Physiologie et Ethologie, Strasbourg 67000, France.
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15
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Hemelrijk CK, Hildenbrandt H. Schools of fish and flocks of birds: their shape and internal structure by self-organization. Interface Focus 2012; 2:726-37. [PMID: 24312726 PMCID: PMC3499122 DOI: 10.1098/rsfs.2012.0025] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/31/2012] [Indexed: 11/12/2022] Open
Abstract
Models of self-organization have proved useful in revealing what processes may underlie characteristics of swarms. In this study, we review model-based explanations for aspects of the shape and internal structure of groups of fish and of birds travelling undisturbed (without predator threat). Our models attribute specific collective traits to locomotory properties. Fish slow down to avoid collisions and swim at a constant depth, whereas birds fly at low variability of speed and lose altitude during turning. In both the models of fish and birds, the 'bearing angle' to the nearest neighbour emerges as a side-effect of the 'blind angle' behind individuals and when group size becomes larger, temporary subgroups may increase the complexity of group shape and internal structure. We discuss evidence for model-based predictions and provide a list of new predictions to be tested empirically.
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Affiliation(s)
- Charlotte K. Hemelrijk
- Behavioural Ecology and Self-Organisation, Centre for Ecological and Evolutionary Studies, University of Groningen, Centre for Life Sciences, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Hemelrijk CK, Hildenbrandt H. Some causes of the variable shape of flocks of birds. PLoS One 2011; 6:e22479. [PMID: 21829627 PMCID: PMC3150374 DOI: 10.1371/journal.pone.0022479] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/22/2011] [Indexed: 11/18/2022] Open
Abstract
Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost). Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris) above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the help of a model of the self-organisation of travelling groups, called StarDisplay, since such a model has also increased our understanding of what causes the oblong shape of schools of fish. The flocking patterns in the model prove to resemble those of real birds, in particular of starlings and rock doves. As to shape, we measure the relative proportions of the flock in several ways, which either depend on the direction of movement or do not. We confirm that flock shape is usually more variable when local differences in movement in the flock are larger. This happens when a) flock size is larger, b) interacting partners are fewer, c) the flock turnings are stronger, and d) individuals roll into the turn. In contrast to our expectations, when variability of speed in the flock is higher, flock shape and the positions of members in the flock are more static. We explain this and indicate the adaptive value of low variability of speed and spatial restriction of interaction and develop testable hypotheses.
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Affiliation(s)
- Charlotte K Hemelrijk
- Behavioural Ecology and Self-Organisation, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands.
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18
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Kurvers RHJM, Adamczyk VMAP, van Wieren SE, Prins HHT. The effect of boldness on decision-making in barnacle geese is group-size-dependent. Proc Biol Sci 2010; 278:2018-24. [PMID: 21123271 PMCID: PMC3107651 DOI: 10.1098/rspb.2010.2266] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups.
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Affiliation(s)
- Ralf H J M Kurvers
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 Wageningen, The Netherlands.
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Hildenbrandt H, Carere C, Hemelrijk C. Self-organized aerial displays of thousands of starlings: a model. Behav Ecol 2010. [DOI: 10.1093/beheco/arq149] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Dijkstra PD, Lindström J, Metcalfe NB, Hemelrijk CK, Brendel M, Seehausen O, Groothuis TGG. FREQUENCY-DEPENDENT SOCIAL DOMINANCE IN A COLOR POLYMORPHIC CICHLID FISH. Evolution 2010; 64:2797-807. [DOI: 10.1111/j.1558-5646.2010.01046.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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21
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Oosten JE, Magnhagen C, Hemelrijk CK. Boldness by habituation and social interactions: a model. Behav Ecol Sociobiol 2010; 64:793-802. [PMID: 20351762 PMCID: PMC2839493 DOI: 10.1007/s00265-009-0896-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 12/03/2009] [Accepted: 12/05/2009] [Indexed: 11/25/2022]
Abstract
Most studies of animal personality attribute personality to genetic traits. But a recent study by Magnhagen and Staffan (Behav Ecol Sociobiol 57:295–303, 2005) on young perch in small groups showed that boldness, a central personality trait, is also shaped by social interactions and by previous experience. The authors measured boldness by recording the duration that an individual spent near a predator and the speed with which it fed there. They found that duration near the predator increased over time and was higher the higher the average boldness of other group members. In addition, the feeding rate of shy individuals was reduced if other members of the same group were bold. The authors supposed that these behavioral dynamics were caused by genetic differences, social interactions, and habituation to the predator. However, they did not quantify exactly how this could happen. In the present study, we therefore use an agent-based model to investigate whether these three factors may explain the empirical findings. We choose an agent-based model because this type of model is especially suited to study the relation between behavior at an individual level and behavioral dynamics at a group level. In our model, individuals were either hiding in vegetation or feeding near a predator, whereby their behavior was affected by habituation and by two social mechanisms: social facilitation to approach the predator and competition over food. We show that even if we start the model with identical individuals, these three mechanisms were sufficient to reproduce the behavioral dynamics of the empirical study, including the consistent differences among individuals. Moreover, if we start the model with individuals that already differ in boldness, the behavioral dynamics produced remained the same. Our results indicate the importance of previous experience and social interactions when studying animal personality empirically.
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Affiliation(s)
- Johanneke E. Oosten
- Theoretical Biology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands
| | - Carin Magnhagen
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
| | - Charlotte K. Hemelrijk
- Theoretical Biology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands
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22
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Puga-Gonzalez I, Hildenbrandt H, Hemelrijk CK. Emergent patterns of social affiliation in primates, a model. PLoS Comput Biol 2009; 5:e1000630. [PMID: 20041175 PMCID: PMC2792710 DOI: 10.1371/journal.pcbi.1000630] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Accepted: 11/30/2009] [Indexed: 12/01/2022] Open
Abstract
Many patterns of affiliative behaviour have been described for primates, for instance: reciprocation and exchange of grooming, grooming others of similar rank, reconciliation of fights, and preferential reconciliation with more valuable partners. For these patterns several functions and underlying cognitive processes have been suggested. It is, however, difficult to imagine how animals may combine these diverse considerations in their mind. Although the co-variation hypothesis, by limiting the social possibilities an individual has, constrains the number of cognitive considerations an individual has to take, it does not present an integrated theory of affiliative patterns either. In the present paper, after surveying patterns of affiliation in egalitarian and despotic macaques, we use an individual-based model with a high potential for self-organisation as a starting point for such an integrative approach. In our model, called GrooFiWorld, individuals group and, upon meeting each other, may perform a dominance interaction of which the outcomes of winning and losing are self-reinforcing. Besides, if individuals think they will be defeated, they consider grooming others. Here, the greater their anxiety is, the greater their "motivation" to groom others. Our model generates patterns similar to many affiliative patterns of empirical data. By merely increasing the intensity of aggression, affiliative patterns in the model change from those resembling egalitarian macaques to those resembling despotic ones. Our model produces such patterns without assuming in the mind of the individual the specific cognitive processes that are usually thought to underlie these patterns (such as recordkeeping of the acts given and received, a tendency to exchange, memory of the former fight, selective attraction to the former opponent, and estimation of the value of a relationship). Our model can be used as a null model to increase our understanding of affiliative behaviour among primates, in particular macaques.
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Affiliation(s)
- Ivan Puga-Gonzalez
- Theoretical Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Hanno Hildenbrandt
- Theoretical Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Charlotte K. Hemelrijk
- Theoretical Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
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Magnhagen C, Bunnefeld N. Express your personality or go along with the group: what determines the behaviour of shoaling perch? Proc Biol Sci 2009; 276:3369-75. [PMID: 19586948 DOI: 10.1098/rspb.2009.0851] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Behavioural syndromes, defined as correlated behaviours in different contexts, have been studied across species and taxa including humans as part of a personality concept. While most studies have focused on solitary individuals, less is known on how shoaling fish compromise between own personality and group behaviour. Risk-taking behaviour in 1-year-old perch (Perca fluviatilis) was observed to compare individual behaviour when in a group and when alone. An experimental design gave the fish the choice between foraging in an open area in the presence of a piscivore and hiding in the vegetation. We quantified the variation accountable by the effect of individuals being in a group, individuals alone and repeated measurements, using hierarchical mixed effects models. Within-group variances were low, but when individuals were later tested alone, individual differences explained most of the variation. Still, the individual best linear unbiased predictors (BLUPs) of time spent in the open area, extracted from the random effects of the mixed effects model, were positively correlated with the corresponding BLUPs when alone. The results indicate that individual behavioural traits are to some degree expressed also within groups. Most fish showed a shyer behaviour when alone, but bolder individuals changed less between treatments than did shyer ones, suggesting a more influential role of bold fish in the group.
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Affiliation(s)
- Carin Magnhagen
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden.
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Dingemanse NJ, Van der Plas F, Wright J, Réale D, Schrama M, Roff DA, Van der Zee E, Barber I. Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology. Proc Biol Sci 2009; 276:1285-93. [PMID: 19129142 PMCID: PMC2660958 DOI: 10.1098/rspb.2008.1555] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Predation plays a central role in evolutionary processes, but little is known about how predators affect the expression of heritable variation, restricting our ability to predict evolutionary effects of predation. We reared families of three-spined stickleback Gasterosteus aculeatus from two populations-one with a history of fish predation (predator sympatric) and one without (predator naive)-and experimentally manipulated experience of predators during ontogeny. For a suite of ecologically relevant behavioural ('personality') and morphological traits, we then estimated two key variance components, additive genetic variance (VA) and residual variance (VR), that jointly shape narrow-sense heritability (h2=VA/(VA+VR)). Both population and treatment differentially affected VA versus VR, hence h2, but only for certain traits. The predator-naive population generally had lower VA and h2 values than the predator-sympatric population for personality behaviours, but not morphological traits. Values of VR and h2 were increased for some, but decreased for other personality traits in the predator-exposed treatment. For some personality traits, VA and h2 values were affected by treatment in the predator-naive population, but not in the predator-sympatric population, implying that the latter harboured less genetic variation for behavioural plasticity. Replication and experimental manipulation of predation regime are now needed to confirm that these population differences were related to variation in predator-induced selection. Cross-environment genetic correlations (rA) were tight for most traits, suggesting that predator-induced selection can affect the evolution of the same trait expressed in the absence of predators. The treatment effects on variance components imply that predators can affect evolution, not only by acting directly as selective agents, but also by influencing the expression of heritable variation.
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Affiliation(s)
- Niels J Dingemanse
- Animal Ecology Group, Department of Behavioural Biology, Centre for Ecological and Evolutionary Studies, Centre for Behaviour and Neurosciences, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands.
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Dijkstra PD, Hemelrijk C, Seehausen O, Groothuis TG. Color polymorphism and intrasexual competition in assemblages of cichlid fish. Behav Ecol 2008. [DOI: 10.1093/beheco/arn125] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Pike TW, Samanta M, Lindström J, Royle NJ. Behavioural phenotype affects social interactions in an animal network. Proc Biol Sci 2008; 275:2515-20. [PMID: 18647713 PMCID: PMC2603202 DOI: 10.1098/rspb.2008.0744] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Animal social networks can be extremely complex and are characterized by highly non-random interactions between group members. However, very little is known about the underlying factors affecting interaction preferences, and hence network structure. One possibility is that behavioural differences between individuals, such as how bold or shy they are, can affect the frequency and distribution of their interactions within a network. We tested this using individually marked three-spined sticklebacks (Gasterosteus aculeatus), and found that bold individuals had fewer overall interactions than shy fish, but tended to distribute their interactions more evenly across all group members. Shy fish, on the other hand, tended to associate preferentially with a small number of other group members, leading to a highly skewed distribution of interactions. This was mediated by the reduced tendency of shy fish to move to a new location within the tank when they were interacting with another individual; bold fish showed no such tendency and were equally likely to move irrespective of whether they were interacting or not. The results show that animal social network structure can be affected by the behavioural composition of group members and have important implications for understanding the spread of information and disease in social groups.
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Affiliation(s)
- Thomas W Pike
- Division of Environmental and Evolutionary Biology, University of Glasgow, Glasgow G12 8QQ, UK.
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Hemelrijk CK, Wantia J, Isler K. Female dominance over males in primates: self-organisation and sexual dimorphism. PLoS One 2008; 3:e2678. [PMID: 18628830 PMCID: PMC2441829 DOI: 10.1371/journal.pone.0002678] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 06/06/2008] [Indexed: 11/19/2022] Open
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.
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Affiliation(s)
- Charlotte K Hemelrijk
- Theoretical Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, Haren, The Netherlands.
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Sellers W, Hill R, Logan B. An agent-based model of group decision making in baboons. Philos Trans R Soc Lond B Biol Sci 2007; 362:1699-710. [PMID: 17428770 PMCID: PMC2440783 DOI: 10.1098/rstb.2007.2064] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We present an agent-based model of the key activities of a troop of chacma baboons (Papio hamadryas ursinus) based on the data collected at De Hoop Nature Reserve in South Africa. We analyse the predictions of the model in terms of how well it is able to duplicate the observed activity patterns of the animals and the relationship between the parameters that control the agent's decision procedure and the model's predictions. At the current stage of model development, we are able to show that across a wide range of decision parameter values, the baboons are able to achieve their energetic and social time requirements. The simulation results also show that decisions concerning movement (group action selection) have the greatest influence on the outcomes. Those cases where the model's predictions fail to agree with the observed activity patterns have highlighted key elements that were missing from the field data, and that would need to be collected in subsequent fieldwork. Based on our experience, we believe group decision making is a fertile field for future research, and agent-based modelling offers considerable scope for understanding group action selection.
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Affiliation(s)
- W.I Sellers
- Faculty of Life Science, University of ManchesterManchester M13 9PL, UK
| | - R.A Hill
- Department of Anthropology, Durham UniversityDurham DH1 3HN, UK
| | - B.S Logan
- School of Computer Science and IT, University of NottinghamNottingham NG8 1BB, UK
- Author for correspondence ()
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Bartolomucci A. Social stress, immune functions and disease in rodents. Front Neuroendocrinol 2007; 28:28-49. [PMID: 17379284 DOI: 10.1016/j.yfrne.2007.02.001] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/22/2006] [Accepted: 02/09/2007] [Indexed: 10/23/2022]
Abstract
The link between social factors, stress and health has been the focus of many interdisciplinary studies mostly because: (i) animals, including humans, often live in societies; (ii) positive and negative social relationships affect disease and well being; (iii) physiological alterations, which parallel social interactions also modulate immune and neuroendocrine functions. This review will focus on studies conducted on laboratory and wild rodents where social factors such as dyadic interactions, individual housing and differential group housing were investigated. The results obtained allow one to conclude that social factors in rodents are causally linked with immune disorders/disease susceptibility. In particular, lower lymphocyte proliferation and antigen-specific-IgG, granulocytosis and lymphopenia, as well as higher tumor induction and progression, are reliably associated with negative social events. Finally, due to the increasing utilization of social stress-based animal models the reliability of the concept of "social stress" and its evolutionary context are re-evaluated.
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Affiliation(s)
- Alessandro Bartolomucci
- Department of Evolutionary and Functional Biology, University of Parma, V.le G.P. Usberti 11A, 43100 Parma, Italy.
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Öst M, Jaatinen K, Steele B. Aggressive females seize central positions and show increased vigilance in brood-rearing coalitions of eiders. Anim Behav 2007. [DOI: 10.1016/j.anbehav.2006.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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