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	Author	Bell, A.M.
	Title	Evolutionary biology: animal personalities			Type
	Year	2007	Publication	Nature	Abbreviated Journal	Nature
	Volume	447	Issue	7144	Pages	539-540
	Keywords	Aggression/physiology/psychology; Animals; Behavior, Animal/physiology; Evolution; Humans; Models, Biological; Personality/genetics/physiology; Reproduction/genetics/physiology; Risk-Taking; Selection (Genetics)
	Abstract
	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	1476-4687	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:17538607			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4099
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	Author	Gonzalez-Fernandez, J.M.; Atta, S.E.
	Title	Facilitated transport of oxygen in the presence of membranes in the diffusion path			Type	Journal Article
	Year	1982	Publication	Biophysical Journal	Abbreviated Journal	Biophys J
	Volume	38	Issue	2	Pages	133-141
	Keywords	Animals; Biological Transport, Active; Cell Membrane/metabolism; Diffusion; Dogs; Horses; Humans; Kinetics; Mathematics; Models, Biological; Muscles/metabolism; Oxygen/metabolism
	Abstract	Most of the experimental observations on facilitated transport have been done with millipore filters, and all the theoretical studies have assumed homogeneous spatial properties. In striated muscle there exist membranes that may impede the diffusion of the carrier myoglobin. In this paper a theoretical study is undertaken to analyze the transport in the presence of membranes in the diffusion path. For the numerical computations physiologically relevant values of the parameters were chosen. The numerical results indicate that the presence of membranes tends to decrease the facilitation. For the nonlinear chemical kinetics of the reaction of oxygen with the carrier, this decrement also depends on the location of the membranes. At the higher oxygen concentration side of each membrane the flow of combined oxygen is transferred to the flow of dissolved oxygen. The reverse process occurs at the lower concentration side. Jump discontinuities of the concentration of the oxygen-carrier compound at each membrane are associated with these transfers. The decrement of facilitation is due to the cumulative effect of these jump discontinuities.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0006-3495	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:7093418			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3806
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	Author	Cameron, E.Z.
	Title	Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism			Type	Journal Article
	Year	2004	Publication	Proceedings. Biological sciences / The Royal Society	Abbreviated Journal	Proc Biol Sci
	Volume	271	Issue	1549	Pages	1723-1728
	Keywords	Age Factors; Animals; Body Constitution; Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/physiology; Models, Biological; Reproduction/physiology; Seasons; Sex Factors; Sex Ratio; Time Factors
	Abstract	Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.
	Address	Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za
	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	0962-8452	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15306293			Approved	no
	Call Number	refbase @ user @			Serial	413
Permanent link to this record



	Author	Grosenick, L.; Clement, T.S.; Fernald, R.D.
	Title	Fish can infer social rank by observation alone			Type	Journal Article
	Year	2007	Publication	Nature	Abbreviated Journal	Nature
	Volume	445	Issue	7126	Pages	429-432
	Keywords	Aggression/physiology; Animals; Cognition/physiology; Female; Fishes/physiology; Learning/physiology; Male; Models, Biological; Social Dominance; Territoriality
	Abstract	Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, TI has since been reported in nonhuman primates, rats and birds. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units. Our findings show that fish use TI when trained on socially relevant stimuli, and that they can make such inferences by using indirect information alone. Further, these bystanders seem to have both spatial and featural representations related to rival abilities, which they can use to make correct inferences depending on what kind of information is available to them. Beyond extending TI to fish and experimentally demonstrating indirect TI learning in animals, these results indicate that a universal mechanism underlying TI is unlikely. Rather, animals probably use multiple domain-specific representations adapted to different social and ecological pressures that they encounter during the course of their natural lives.
	Address	Department of Biological Sciences, Stanford University, Stanford, California, 94305, USA. logang@stanford.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	1476-4687	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:17251980			Approved	no
	Call Number	refbase @ user @			Serial	600
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	Author	Biro, D.; Sumpter, D.J.T.; Meade, J.; Guilford, T.
	Title	From Compromise to Leadership in Pigeon Homing			Type	Journal Article
	Year	2006	Publication	Current Biology	Abbreviated Journal	Curr Biol
	Volume	16	Issue	21	Pages	2123-2128
	Keywords	Animal Migration; Animals; Columbidae/physiology; Decision Making; Flight, Animal; Homing Behavior; Models, Biological; Orientation; Social Behavior; *Social Dominance
	Abstract	Summary A central problem faced by animals traveling in groups is how navigational decisions by group members are integrated, especially when members cannot assess which individuals are best informed or have conflicting information or interests , , , and . Pigeons are now known to recapitulate faithfully their individually distinct habitual routes home , and , and this provides a novel paradigm for investigating collective decisions during flight under varying levels of interindividual conflict. Using high-precision GPS tracking of pairs of pigeons, we found that if conflict between two birds' directional preferences was small, individuals averaged their routes, whereas if conflict rose over a critical threshold, either the pair split or one of the birds became the leader. Modeling such paired decision-making showed that both outcomes--compromise and leadership--could emerge from the same set of simple behavioral rules. Pairs also navigated more efficiently than did the individuals of which they were composed, even though leadership was not necessarily assumed by the more efficient bird. In the context of mass migration of birds and other animals, our results imply that simple self-organizing rules can produce behaviors that improve accuracy in decision-making and thus benefit individuals traveling in groups , and .
	Address	Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom. daro.biro@zoo.ox.ac.uk
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	Englisch	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:17084696			Approved	no
	Call Number				Serial	2026
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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	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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	Author	Wilson, A.M.; McGuigan, M.P.; Su, A.; van Den Bogert, A.J.
	Title	Horses damp the spring in their step			Type	Journal Article
	Year	2001	Publication	Nature	Abbreviated Journal	Nature
	Volume	414	Issue	6866	Pages	895-899
	Keywords	Animals; Biomechanics; Elasticity; Forelimb; Gait; Horses/anatomy & histology/physiology; Leg Bones/physiology; Locomotion; Models, Biological; Muscle Fibers/physiology; Muscle, Skeletal/anatomy & histology/physiology; Tendons/anatomy & histology/physiology; Vibration
	Abstract	The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.
	Address	Department of Veterinary Basic Sciences, The Royal Veterinary College, Hatfield, Herts AL9 7TA, UK. awilson@rvc.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:11780059			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	2300
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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	Wolf, M.; van Doorn, G.S.; Leimar, O.; Weissing, F.J.
	Title	Life-history trade-offs favour the evolution of animal personalities			Type	Journal Article
	Year	2007	Publication	Nature	Abbreviated Journal	Nature
	Volume	447	Issue	7144	Pages	581-584
	Keywords	Aggression/physiology/psychology; Animals; Behavior, Animal/physiology; Evolution; Exploratory Behavior/physiology; Models, Biological; Personality/*physiology; Predatory Behavior/physiology; Reproduction/physiology; Risk-Taking; Selection (Genetics)
	Abstract	In recent years evidence has been accumulating that personalities are not only found in humans but also in a wide range of other animal species. Individuals differ consistently in their behavioural tendencies and the behaviour in one context is correlated with the behaviour in multiple other contexts. From an adaptive perspective, the evolution of animal personalities is still a mystery, because a more flexible structure of behaviour should provide a selective advantage. Accordingly, many researchers view personalities as resulting from constraints imposed by the architecture of behaviour (but see ref. 12). In contrast, we show here that animal personalities can be given an adaptive explanation. Our argument is based on the insight that the trade-off between current and future reproduction often results in polymorphic populations in which some individuals put more emphasis on future fitness returns than others. Life-history theory predicts that such differences in fitness expectations should result in systematic differences in risk-taking behaviour. Individuals with high future expectations (who have much to lose) should be more risk-averse than individuals with low expectations. This applies to all kinds of risky situations, so individuals should consistently differ in their behaviour. By means of an evolutionary model we demonstrate that this basic principle results in the evolution of animal personalities. It simultaneously explains the coexistence of behavioural types, the consistency of behaviour through time and the structure of behavioural correlations across contexts. Moreover, it explains the common finding that explorative behaviour and risk-related traits like boldness and aggressiveness are common characteristics of animal personalities.
	Address	Theoretical Biology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Kerklaan 30, 9751 NN Haren, 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	1476-4687	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:17538618			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4098
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