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Author | Viscido, S.V.; Miller, M.; Wethey, D.S. | ||||
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 | 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 | ||||
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Language | English | Summary Language | Original Title | ||
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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 | Viscido, S.V.; Miller, M.; Wethey, D.S. | ||||
Title | The response of a selfish herd to an attack from outside the group perimeter | Type | Journal Article | ||
Year | 2001 | Publication | Journal of theoretical biology | Abbreviated Journal | J. Theor. Biol. |
Volume | 208 | Issue | 3 | Pages | 315-328 |
Keywords | Animals; *Behavior, Animal; *Computer Simulation; Models, Biological; *Movement; Predatory Behavior | ||||
Abstract | According to the selfish herd hypothesis, animals can decrease predation risk by moving toward one another if the predator can appear anywhere and will attack the nearest target. Previous studies have shown that aggregations can form using simple movement rules designed to decrease each animal's Domain of Danger. However, if the predator attacks from outside the group's perimeter, these simple movement rules might not lead to aggregation. To test whether simple selfish movement rules would decrease predation risk for those situations when the predator attacks from outside the flock perimeter, we constructed a computer model that allowed flocks of 75 simulated fiddler crabs to react to one another, and to a predator attacking from 7 m away. We attacked simulated crab flocks with predators of different sizes and attack speeds, and computed relative predation risk after 120 time steps. Final trajectories showed flight toward the center of the flock, but curving away from the predator. Path curvature depended on the predator's size and approach speed. The average crab experienced a greater decrease in predation risk when the predator was small or slow moving. Regardless of the predator's size and speed, however, predation risk always decreased as long as crabs took their flock-mates into account. We conclude that, even when flight away from an external predator occurs, the selfish avoidance of danger can lead to aggregation. | ||||
Address | Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, U.S.A. viscido@u.washington.edu | ||||
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Language | English | Summary Language | Original Title | ||
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ISSN | 0022-5193 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:11207093 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 555 | ||
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Author | Drent, P.J.; van Oers, K.; van Noordwijk, A.J. | ||||
Title | Realized heritability of personalities in the great tit (Parus major) | Type | Journal Article | ||
Year | 2003 | Publication | Proceedings. Biological sciences / The Royal Society | Abbreviated Journal | Proc Biol Sci |
Volume | 270 | Issue | 1510 | Pages | 45-51 |
Keywords | Aggression; Animals; Animals, Domestic; Animals, Wild; *Behavior, Animal; Breeding; Exploratory Behavior; Female; *Heredity; Male; Selection (Genetics); Songbirds/*genetics/*physiology; Variation (Genetics) | ||||
Abstract | Behaviour under conditions of mild stress shows consistent patterns in all vertebrates: exploratory behaviour, boldness, aggressiveness covary in the same way. The existence of highly consistent individual variation in these behavioural strategies, also referred to as personalities or coping styles, allows us to measure the behaviour under standardized conditions on birds bred in captivity, link the standardized measurements to the behaviour under natural conditions and measure natural selection in the field. We have bred the great tit (Parus major), a classical model species for the study of behaviour under natural conditions, in captivity. Here, we report a realized heritability of 54 +/- 5% for early exploratory behaviour, based on four generations of bi-directional artificial selection. In addition to this, we measured hand-reared juveniles and their wild-caught parents in the laboratory. The heritability found in the mid-offspring-mid-parent regression was significantly different from zero. We have thus established the presence of considerable amounts of genetic variation for personality types in a wild bird. | ||||
Address | Netherlands Institute of Ecology, PO Box 40, 6666 ZG Heteren, The Netherlands. drent@cto.nioo.knaw.nl | ||||
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Language | English | Summary Language | Original Title | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 0962-8452 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:12590770 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 591 | ||
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Author | Hare, B.; Brown, M.; Williamson, C.; Tomasello, M. | ||||
Title | The domestication of social cognition in dogs | Type | Journal Article | ||
Year | 2002 | Publication | Science (New York, N.Y.) | Abbreviated Journal | Science |
Volume | 298 | Issue | 5598 | Pages | 1634-1636 |
Keywords | Animals; *Animals, Domestic; *Behavior, Animal; *Cognition; *Cues; *Dogs; Food; Humans; Memory; Pan troglodytes; *Social Behavior; Species Specificity; Vision; Wolves | ||||
Abstract | Dogs are more skillful than great apes at a number of tasks in which they must read human communicative signals indicating the location of hidden food. In this study, we found that wolves who were raised by humans do not show these same skills, whereas domestic dog puppies only a few weeks old, even those that have had little human contact, do show these skills. These findings suggest that during the process of domestication, dogs have been selected for a set of social-cognitive abilities that enable them to communicate with humans in unique ways. | ||||
Address | Department of Anthropology, Harvard University, Cambridge, MA 02138, USA. bhare@fas.harvard.edu | ||||
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Language | English | Summary Language | Original Title | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 1095-9203 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:12446914 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 595 | ||
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Author | Boyd, L. | ||||
Title | Behavior problems of equids in zoos | Type | Journal Article | ||
Year | 1986 | Publication | The Veterinary clinics of North America. Equine practice | Abbreviated Journal | Vet Clin North Am Equine Pract |
Volume | 2 | Issue | 3 | Pages | 653-664 |
Keywords | Aerophagy/veterinary; Aggression/psychology; Animals; *Animals, Zoo; *Behavior, Animal; Coprophagia/psychology; Female; *Horses; Impotence/veterinary; Male; Mastication; Motor Activity; *Perissodactyla; Pregnancy; Sexual Behavior, Animal; Social Environment | ||||
Abstract | Behavior problems in zoo equids commonly result from a failure to provide for needs basic to equine nature. Equids are gregarious, and failure to provide companions may result in pacing. Wild equids spend 60 to 70 per cent of their time grazing, and failure to provide ad libitum roughage contributes to the problems of pacing, cribbing, wood chewing, and coprophagia. Mimicking the normal processes of juvenile dispersal, bachelor-herd formation, and mate acquisition reduces the likelihood of agonistic and reproductive behavior problems. Infanticide can be avoided by introducing new stallions to herds containing only nonpregnant mares and older foals. | ||||
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Language | English | Summary Language | Original Title | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 0749-0739 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:3492252 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 660 | ||
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Author | Heyes, C.M. | ||||
Title | Social learning in animals: categories and mechanisms | Type | Journal Article | ||
Year | 1994 | Publication | Biological reviews of the Cambridge Philosophical Society | Abbreviated Journal | Biol. Rev. |
Volume | 69 | Issue | 2 | Pages | 207-231 |
Keywords | Animals; *Behavior, Animal; Conditioning (Psychology); *Learning; Reinforcement (Psychology); *Social Behavior | ||||
Abstract | There has been relatively little research on the psychological mechanisms of social learning. This may be due, in part, to the practice of distinguishing categories of social learning in relation to ill-defined mechanisms (Davis, 1973; Galef, 1988). This practice both makes it difficult to identify empirically examples of different types of social learning, and gives the false impression that the mechanisms responsible for social learning are clearly understood. It has been proposed that social learning phenomena be subsumed within the categorization scheme currently used by investigators of asocial learning. This scheme distinguishes categories of learning according to observable conditions, namely, the type of experience that gives rise to a change in an animal (single stimulus vs. stimulus-stimulus relationship vs. response-reinforcer relationship), and the type of behaviour in which this change is detected (response evocation vs. learnability) (Rescorla, 1988). Specifically, three alignments have been proposed: (i) stimulus enhancement with single stimulus learning, (ii) observational conditioning with stimulus-stimulus learning, or Pavlovian conditioning, and (iii) observational learning with response-reinforcer learning, or instrumental conditioning. If, as the proposed alignments suggest, the conditions of social and asocial learning are the same, there is some reason to believe that the mechanisms underlying the two sets of phenomena are also the same. This is so if one makes the relatively uncontroversial assumption that phenomena which occur under similar conditions tend to be controlled by similar mechanisms. However, the proposed alignments are intended to be a set of hypotheses, rather than conclusions, about the mechanisms of social learning; as a basis for further research in which animal learning theory is applied to social learning. A concerted attempt to apply animal learning theory to social learning, to find out whether the same mechanisms are responsible for social and asocial learning, could lead both to refinements of the general theory, and to a better understanding of the mechanisms of social learning. There are precedents for these positive developments in research applying animal learning theory to food aversion learning (e.g. Domjan, 1983; Rozin & Schull, 1988) and imprinting (e.g. Bolhuis, de Vox & Kruit, 1990; Hollis, ten Cate & Bateson, 1991). Like social learning, these phenomena almost certainly play distinctive roles in the antogeny of adaptive behaviour, and they are customarily regarded as 'special kinds' of learning (Shettleworth, 1993).(ABSTRACT TRUNCATED AT 400 WORDS) | ||||
Address | Department of Psychology, University College London | ||||
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Language | English | Summary Language | Original Title | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 1464-7931 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:8054445 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 708 | ||
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Author | Hamilton, W.D. | ||||
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 | 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 | ||
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ISSN | 0022-5193 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:5104951 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 771 | ||
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Author | Cooper, J.J. | ||||
Title | Comparative learning theory and its application in the training of horses | Type | Journal Article | ||
Year | 1998 | Publication | Equine veterinary journal. Supplement | Abbreviated Journal | Equine Vet J Suppl |
Volume | Issue | 27 | Pages | 39-43 | |
Keywords | Animals; *Behavior, Animal; Conditioning (Psychology); Horses/*psychology; *Learning; Reinforcement (Psychology) | ||||
Abstract | Training can best be explained as a process that occurs through stimulus-response-reinforcement chains, whereby animals are conditioned to associate cues in their environment, with specific behavioural responses and their rewarding consequences. Research into learning in horses has concentrated on their powers of discrimination and on primary positive reinforcement schedules, where the correct response is paired with a desirable consequence such as food. In contrast, a number of other learning processes that are used in training have been widely studied in other species, but have received little scientific investigation in the horse. These include: negative reinforcement, where performance of the correct response is followed by removal of, or decrease in, intensity of a unpleasant stimulus; punishment, where an incorrect response is paired with an undesirable consequence, but without consistent prior warning; secondary conditioning, where a natural primary reinforcer such as food is closely associated with an arbitrary secondary reinforcer such as vocal praise; and variable or partial conditioning, where once the correct response has been learnt, reinforcement is presented according to an intermittent schedule to increase resistance to extinction outside of training. | ||||
Address | Department of Zoology, University of Oxford, UK | ||||
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Language | English | Summary Language | Original Title | ||
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Notes | PMID:10485003 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 846 | ||
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Author | Burden, F.; Trawford, A. | ||||
Title | Equine interspecies aggression Comment on | Type | |||
Year | 2006 | Publication | The Veterinary record | Abbreviated Journal | Vet. Rec. |
Volume | 159 | Issue | 25 | Pages | 859-860 |
Keywords | *Aggression; Animals; *Behavior, Animal; Cats; Dogs; Equidae | ||||
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Language | English | Summary Language | Original Title | ||
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ISSN | 0042-4900 | ISBN | Medium | ||
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Notes | PMID:17172484 | Approved | no | ||
Call Number | Serial | 1777 | |||
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Author | Bachmann, I.; Audige, L.; Stauffacher, M. | ||||
Title | Risk factors associated with behavioural disorders of crib-biting, weaving and box-walking in Swiss horses | Type | Journal Article | ||
Year | 2003 | Publication | Equine Veterinary Journal | Abbreviated Journal | Equine Vet J |
Volume | 35 | Issue | 2 | Pages | 158-163 |
Keywords | Animal Husbandry/*methods; Animals; *Behavior, Animal; Confounding Factors (Epidemiology); Data Collection; Female; Horse Diseases/epidemiology/*etiology/prevention & control; Horses; *Housing, Animal; Male; Mental Disorders/epidemiology/etiology/prevention & control/*veterinary; Prevalence; Regression Analysis; Risk Factors; *Stereotyped Behavior; Switzerland/epidemiology | ||||
Abstract | REASONS FOR PERFORMING STUDY: Studies on the prevalence of behavioural disorders in horses and on associated risk factors have revealed inconsistent results. There are many studies on the neuropharmacological, surgical or mechanical therapy of stereotypies, but little is known about their causation. OBJECTIVES: To explore risk factors associated with the occurrence of behavioural disorders in horses. METHODS: A sample of horse owners, selected randomly and representative for Switzerland, was contacted in a postal survey. Answers were provided for 622 stables (response rate 35.2%). Individual data of 2,341 horses were examined with path analysis (multivariable linear and logistic regression), and adjustment made for possible confounding effects due to age and breed. RESULTS: Out of 60 possible risk factors, 11 were associated with the outcome at the univariable level (null-hypothesis path model) and 3 factors remained after the backward logistic regression procedure. Mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive, fed 4 times a day and without daily pasture, had increased odds of displaying crib-biting, weaving and box-walking. Furthermore, indirect associations of 5 factors with the outcome were identified. CONCLUSIONS: The final logistic regression model of risk factors leads to the hypotheses that causal prevention of stereotypic behaviours should be based upon housing and management conditions which allow tactile contact with other horses (e.g. mutual grooming), daily free movement (paddock or pasture), as well as the provision of high amounts of roughage but of little or no concentrates. POTENTIAL CLINICAL RELEVANCE: It is one of the aims of population medicine to prevent the development of behavioural disorders. Further research is needed to test the concluding hypotheses in experimental studies or to verify them in the context of similar observational studies. | ||||
Address | Institute of Animal Sciences, Swiss Federal Institute of Technology (ETH), LFW B55. 1, CH-8092 Zurich, Switzerland | ||||
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ISSN | 0425-1644 | ISBN | Medium | ||
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Notes | PMID:12638792 | Approved | no | ||
Call Number | Serial | 1907 | |||
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