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	Author	Santamaria, S.; Bobbert, M.F.; Back, W.; Barneveld, A.; van Weeren, P.R.
	Title	Effect of early training on the jumping technique of horses			Type	Journal Article
	Year	2005	Publication	American Journal of Veterinary Research	Abbreviated Journal	Am J Vet Res
	Volume	66	Issue	3	Pages	418-424
	Keywords	Age Factors; Analysis of Variance; Animals; Biomechanics; Forelimb/physiology; Gait/physiology; Hindlimb/physiology; Horses/growth & development/physiology; Locomotion/physiology; Models, Biological; Physical Conditioning, Animal/methods
	Abstract	OBJECTIVE: To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally. ANIMALS: 40 Dutch Warmblood horses. PROCEDURE: The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance. RESULTS: Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition. CONCLUSIONS AND CLINICAL RELEVANCE: Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent.
	Address	Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, NL-3584 CM Utrecht, The Netherlands
	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	0002-9645	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15822585			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4037
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	Author	Uehara, T.; Yokomizo, H.; Iwasa, Y.
	Title	Mate-choice copying as Bayesian decision making			Type	Journal Article
	Year	2005	Publication	The American naturalist	Abbreviated Journal	Am Nat
	Volume	165	Issue	3	Pages	403-410
	Keywords	Animals; Bayes Theorem; Choice Behavior; Female; Male; Models, Biological; Sexual Behavior, Animal
	Abstract	Mate-choice copying by females has been reported in fishes (e.g., guppies) and lekking birds. Presumably, females assess males' quality using both information from direct observation of males and information acquired by observing other females' choices. Here, we study mathematically the conditions under which mate-choice copying is advantageous on the basis of Bayesian decision theory. A female may observe the mate choice of another female, called the model female, who has performed an optimal choice based on her own judgment. The conditions required for the focal female to choose the same mate as that chosen by the model female should depend on the male's appearance to her, the reliability of her own judgment of male quality, and the reliability of the model females. When three or more females are involved, the optimal mate choice critically depends on whether multiple model females make decisions independently or they themselves copy the choices of others. If two equally reliable females choose different males, the choice of the second female, made knowing the choice of the first, should have a stronger effect on the choice of the third (focal) female. This “last-choice precedence” should be tested experimentally.
	Address	Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. uehara@bio-math.biology.kyushu-u.ac.jp
	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	1537-5323	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15729669			Approved	no
	Call Number				Serial	1821
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	Author	Munoz-Sanz, A.
	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	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	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
	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	0022-5193	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:11207093			Approved	no
	Call Number	refbase @ user @			Serial	555
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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.
	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	0022-5193	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:5104951			Approved	no
	Call Number	refbase @ user @			Serial	771
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	Author	Harcourt, J.L.; Ang, T.Z.; Sweetman, G.; Johnstone, R.A.; Manica, A.
	Title	Social feedback and the emergence of leaders and followers			Type	Journal Article
	Year	2009	Publication	Current Biology : CB	Abbreviated Journal	Curr Biol
	Volume	19	Issue	3	Pages	248-252
	Keywords	Analysis of Variance; Animals; Appetitive Behavior/physiology; Feedback; Great Britain; Leadership; Markov Chains; Models, Biological; Monte Carlo Method; Smegmamorpha/physiology; Social Behavior; Video Recording
	Abstract	In many animal groups, certain individuals consistently appear at the forefront of coordinated movements [1-4]. How such leaders emerge is poorly understood [5, 6]. Here, we show that in pairs of sticklebacks, Gasterosteus aculeatus, leadership arises from individual differences in the way that fish respond to their partner's movements. Having first established that individuals differed in their propensity to leave cover in order to look for food, we randomly paired fish of varying boldness, and we used a Markov Chain model to infer the individual rules underlying their joint behavior. Both fish in a pair responded to each other's movements-each was more likely to leave cover if the other was already out and to return if the other had already returned. However, we found that bolder individuals displayed greater initiative and were less responsive to their partners, whereas shyer individuals displayed less initiative but followed their partners more faithfully; they also, as followers, elicited greater leadership tendencies in their bold partners. We conclude that leadership in this case is reinforced by positive social feedback.
	Address	Department of Zoology, University of Cambridge, Cambridge, UK
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0960-9822	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:19185497			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5123
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	Author	Waite, T.A.
	Title	Interruptions improve choice performance in gray jays: prolonged information processing versus minimization of costly errors			Type	Journal Article
	Year	2002	Publication	Animal Cognition	Abbreviated Journal	Anim. Cogn.
	Volume	5	Issue	4	Pages	209-214
	Keywords	Animals; Behavior, Animal; Choice Behavior; Female; Learning; Male; Models, Biological; Motivation; Reinforcement Schedule; Songbirds/*physiology; Time Factors
	Abstract	Under the assumption that selection favors minimization of costly errors, erroneous choice may be common when its fitness cost is low. According to an adaptive-choice model, this cost depends on the rate at which an animal encounters the choice: the higher this rate, the smaller the cost of choosing a less valuable option. Errors should thus be more common when interruptions to foraging are shorter. A previous experiment supported this prediction: gray jays, Perisoreus canadensis, were more error prone when subjected to shorter delays to access to food rewards. This pattern, though, is also predicted by an attentional-constraints model. Because the subjects were able to inspect the rewards during delays, their improved performance when subjected to longer delays could have been a byproduct of the experimentally prolonged opportunity for information processing. To evaluate this possibility, a follow-up experiment manipulated both delay to access and whether rewards could be inspected during delays. Depriving jays of the opportunity to inspect rewards (using opaque lids) induced only a small, nonsignificant increase in error rate. This effect was independent of length of delay and so the jays' improved performance when subjected to longer delays was not simply a byproduct of prolonged information processing. More definitively, even when the jays were prevented from inspecting rewards during delays, their performance improved when subjected to longer delays. The findings are thus consistent with the adaptive-choice model.
	Address	Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 1735 Neil Avenue, Columbus, OH 43210-1293, USA. waite.1@osu.edu
	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	1435-9448	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:12461598			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	2592
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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	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	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
	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	0022-5193	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:12202112			Approved	no
	Call Number	refbase @ user @			Serial	554
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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	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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