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Author Young, L.E.; Rogers, K.; Wood, J.L.N. doi  openurl
  Title Left ventricular size and systolic function in Thoroughbred racehorses and their relationships to race performance Type Journal Article
  Year 2005 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol  
  Volume 99 Issue 4 Pages 1278-1285  
  Keywords *Adaptation, Physiological; Aging/physiology; Animal Husbandry; Animals; *Echocardiography; Female; Heart/*physiology; Heart Ventricles; Horses/*physiology; Male; *Physical Conditioning, Animal; Running/*physiology; Stroke Volume; Systole; Task Performance and Analysis  
  Abstract Cardiac morphology in human athletes is known to differ, depending on the sports-specific endurance component of their events, whereas anecdotes abound about superlative athletes with large hearts. As the heart determines stroke volume and maximum O(2) uptake in mammals, we undertook a study to test the hypothesis that the morphology of the equine heart would differ between trained horses, depending on race type, and that left ventricular size would be greatest in elite performers. Echocardiography was performed in 482 race-fit Thoroughbreds engaged in either flat (1,000-2,500 m) or jump racing (3,200-6,400 m). Body weight and sex-adjusted measures of left ventricular size were largest in horses engaged in jump racing over fixed fences, compared with horses running shorter distances on the flat (range 8-16%). The observed differences in cardiac morphologies suggest that subtle differences in training and competition result in cardiac adaptations that are appropriate to the endurance component of the horses' event. Derived left ventricular mass was strongly associated with published rating (quality) in horses racing over longer distances in jump races (P < or = 0.001), but less so for horses in flat races. Rather, left ventricular ejection fraction and left ventricular mass combined were positively associated with race rating in older flat racehorses running over sprint (<1,408 m) and longer distances (>1,408 m), explaining 25-35% of overall variation in performance, as well as being closely associated with performance in longer races over jumps (23%). These data provide the first direct evidence that cardiac size influences athletic performance in a group of mammalian running athletes.  
  Address Centre for Equine Studies, Animal Health Trust, Newmarket, Suffolk, UK. lesley.young@aht.org.uk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  ISSN (down) 8750-7587 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15920096 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3768  
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Author Nicol, C.J. openurl 
  Title Development, direction, and damage limitation: social learning in domestic fowl Type Journal Article
  Year 2004 Publication Learning & behavior : a Psychonomic Society publication Abbreviated Journal Learn Behav  
  Volume 32 Issue 1 Pages 72-81  
  Keywords Adaptation, Psychological; Age Factors; Animals; Behavior, Animal; *Chickens; *Feeding Behavior; *Food Preferences; *Imitative Behavior; Imprinting (Psychology); *Learning; Maternal Behavior; Reinforcement (Psychology); *Social Environment; *Social Facilitation  
  Abstract This review highlights two areas of particular interest in the study of social learning in fowl. First, the role of social learning in the development of feeding and foraging behavior in young chicks and older birds is described. The role of the hen as a demonstrator and possible teacher is considered, and the subsequent social influence of brood mates and other companions on food avoidance and food preference learning is discussed. Second, the way in which work on domestic fowl has contributed to an understanding of the importance of directed social learning is examined. The well-characterized hierarchical social organization of small chicken flocks has been used to design studies which demonstrate that the probability of social transmission is strongly influenced by social relationships between birds. The practical implications of understanding the role of social learning in the spread of injurious behaviors in this economically important species are briefly considered.  
  Address Department of Clinical Veterinary Science, University of Bristol, Langford, Bristol, England. c.j.nicol@bristol.ac.uk  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN (down) 1543-4494 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15161142 Approved no  
  Call Number refbase @ user @ Serial 75  
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Author Zentall, T.R. openurl 
  Title Action imitation in birds Type Journal Article
  Year 2004 Publication Learning & behavior : a Psychonomic Society publication Abbreviated Journal Learn Behav  
  Volume 32 Issue 1 Pages 15-23  
  Keywords Adaptation, Psychological; Animals; *Birds; *Imitative Behavior; Imprinting (Psychology); *Learning; Motivation; Psychological Theory; *Social Environment; *Social Facilitation; Vocalization, Animal  
  Abstract Action imitation, once thought to be a behavior almost exclusively limited to humans and the great apes, surprisingly also has been found in a number of bird species. Because imitation has been viewed by some psychologists as a form of intelligent behavior, there has been interest in how it is distributed among animal species. Although the mechanisms responsible for action imitation are not clear, we are now at least beginning to understand the conditions under which it occurs. In this article, I try to identify and differentiate the various forms of socially influenced behavior (species-typical social reactions, social effects on motivation, social effects on perception, socially influenced learning, and action imitation) and explain why it is important to differentiate imitation from other forms of social influence. I also examine some of the variables that appear to be involved in the occurrence of imitation. Finally, I speculate about why a number of bird species, but few mammal species, appear to imitate.  
  Address Department of Psychology, University of Kentucky, Lexington, Kentucky 40506, USA. zentall@uky.edu  
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  ISSN (down) 1543-4494 ISBN Medium  
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  Notes PMID:15161137 Approved no  
  Call Number refbase @ user @ Serial 230  
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Author Gibson, B.M.; Shettleworth, S.J. openurl 
  Title Competition among spatial cues in a naturalistic food-carrying task Type Journal Article
  Year 2003 Publication Learning & behavior : a Psychonomic Society publication Abbreviated Journal Learn Behav  
  Volume 31 Issue 2 Pages 143-159  
  Keywords Adaptation, Psychological; Animals; Appetitive Behavior; *Association Learning; *Attention; Choice Behavior; *Cues; *Discrimination Learning; Male; Rats; Rats, Long-Evans; Space Perception; *Spatial Behavior  
  Abstract Rats collected nuts from a container in a large arena in four experiments testing how learning about a beacon or cue at a goal interacts with learning about other spatial cues (place learning). Place learning was quick, with little evidence of competition from the beacon (Experiments 1 and 2). Rats trained to approach a beacon regardless of its location were subsequently impaired when the well-learned beacon was removed and other spatial cues identified the location of the goal (Experiment 3). The competition between beacon and place cues reflected learned irrelevance for place cues (Experiment 4). The findings differ from those of some studies of associative interactions between cue and place learning in other paradigms.  
  Address University of Toronto, Toronto, Ontario, Canada  
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  Language English Summary Language Original Title  
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  ISSN (down) 1543-4494 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12882373 Approved no  
  Call Number refbase @ user @ Serial 368  
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Author Whiten, A.; Horner, V.; Litchfield, C.A.; Marshall-Pescini, S. url  doi
openurl 
  Title How do apes ape? Type Journal Article
  Year 2004 Publication Learning & Behavior Abbreviated Journal Learn. Behav.  
  Volume 32 Issue 1 Pages 36-52  
  Keywords Adaptation, Psychological; Animals; Behavior, Animal; Hominidae/*psychology; *Imitative Behavior; Imprinting (Psychology); *Learning; Psychological Theory; *Social Environment; *Social Facilitation  
  Abstract In the wake of telling critiques of the foundations on which earlier conclusions were based, the last 15 years have witnessed a renaissance in the study of social learning in apes. As a result, we are able to review 31 experimental studies from this period in which social learning in chimpanzees, gorillas, and orangutans has been investigated. The principal question framed at the beginning of this era, Do apes ape? has been answered in the affirmative, at least in certain conditions. The more interesting question now is, thus, How do apes ape? Answering this question has engendered richer taxonomies of the range of social-learning processes at work and new methodologies to uncover them. Together, these studies suggest that apes ape by employing a portfolio of alternative social-learning processes in flexibly adaptive ways, in conjunction with nonsocial learning. We conclude by sketching the kind of decision tree that appears to underlie the deployment of these alternatives.  
  Address Centre for Social Learning and Cognitive Evolution, Scottish Primate Research Group, School of Psychology, University of St. Andrews, St. Andrews, Fife, Scotland. a.whiten@st-and.ac.uk  
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  ISSN (down) 1543-4494 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15161139 Approved no  
  Call Number refbase @ user @ Serial 734  
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Author Fragaszy, D.; Visalberghi, E. openurl 
  Title Socially biased learning in monkeys Type Journal Article
  Year 2004 Publication Learning & behavior : a Psychonomic Society publication Abbreviated Journal Learn Behav  
  Volume 32 Issue 1 Pages 24-35  
  Keywords Adaptation, Psychological; Animal Communication; Animals; Behavior, Animal; *Feeding Behavior/psychology; Food Preferences/psychology; Haplorhini/*psychology; *Imitative Behavior; Imprinting (Psychology); *Learning; *Social Environment; *Social Facilitation  
  Abstract We review socially biased learning about food and problem solving in monkeys, relying especially on studies with tufted capuchin monkeys (Cebus apella) and callitrichid monkeys. Capuchin monkeys most effectively learn to solve a new problem when they can act jointly with an experienced partner in a socially tolerant setting and when the problem can be solved by direct action on an object or substrate, but they do not learn by imitation. Capuchin monkeys are motivated to eat foods, whether familiar or novel, when they are with others that are eating, regardless of what the others are eating. Thus, social bias in learning about foods is indirect and mediated by facilitation of feeding. In most respects, social biases in learning are similar in capuchins and callitrichids, except that callitrichids provide more specific behavioral cues to others about the availability and palatability of foods. Callitrichids generally are more tolerant toward group members and coordinate their activity in space and time more closely than capuchins do. These characteristics support stronger social biases in learning in callitrichids than in capuchins in some situations. On the other hand, callitrichids' more limited range of manipulative behaviors, greater neophobia, and greater sensitivity to the risk of predation restricts what these monkeys learn in comparison with capuchins. We suggest that socially biased learning is always the collective outcome of interacting physical, social, and individual factors, and that differences across populations and species in social bias in learning reflect variations in all these dimensions. Progress in understanding socially biased learning in nonhuman species will be aided by the development of appropriately detailed models of the richly interconnected processes affecting learning.  
  Address Psychology Department, University of Georgia, Athens, Georgia 30602, USA. doree@uga.edu  
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  Language English Summary Language Original Title  
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  ISSN (down) 1543-4494 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15161138 Approved no  
  Call Number refbase @ user @ Serial 828  
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Author Carroll, J.; Murphy, C.J.; Neitz, M.; Hoeve, J.N.; Neitz, J. doi  openurl
  Title Photopigment basis for dichromatic color vision in the horse Type Journal Article
  Year 2001 Publication Journal of Vision Abbreviated Journal J Vis  
  Volume 1 Issue 2 Pages 80-87  
  Keywords Adaptation, Physiological; Animals; Color Perception/*physiology; Cones (Retina)/chemistry/*physiology; Electroretinography; Horses/*physiology; Photic Stimulation; Phototransduction/physiology; Retinal Pigments/analysis/*physiology; Visual Perception/physiology  
  Abstract Horses, like other ungulates, are active in the day, at dusk, dawn, and night; and, they have eyes designed to have both high sensitivity for vision in dim light and good visual acuity under higher light levels (Walls, 1942). Typically, daytime activity is associated with the presence of multiple cone classes and color-vision capacity (Jacobs, 1993). Previous studies in other ungulates, such as pigs, goats, cows, sheep and deer, have shown that they have two spectrally different cone types, and hence, at least the photopigment basis for dichromatic color vision (Neitz & Jacobs, 1989; Jacobs, Deegan II, Neitz, Murphy, Miller, & Marchinton, 1994; Jacobs, Deegan II, & Neitz, 1998). Here, electroretinogram flicker photometry was used to measure the spectral sensitivities of the cones in the domestic horse (Equus caballus). Two distinct spectral mechanisms were identified and are consistent with the presence of a short-wavelength-sensitive (S) and a middle-to-long-wavelength-sensitive (M/L) cone. The spectral sensitivity of the S cone was estimated to have a peak of 428 nm, while the M/L cone had a peak of 539 nm. These two cone types would provide the basis for dichromatic color vision consistent with recent results from behavioral testing of horses (Macuda & Timney, 1999; Macuda & Timney, 2000; Timney & Macuda, 2001). The spectral peak of the M/L cone photopigment measured here, in vivo, is similar to that obtained when the gene was sequenced, cloned, and expressed in vitro (Yokoyama & Radlwimmer, 1999). Of the ungulates that have been studied to date, all have the photopigment basis for dichromatic color vision; however, they differ considerably from one another in the spectral tuning of their cone pigments. These differences may represent adaptations to the different visual requirements of different species.  
  Address Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  ISSN (down) 1534-7362 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12678603 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4060  
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Author Potts, R. doi  openurl
  Title Variability selection in hominid evolution Type Journal Article
  Year 1998 Publication Evolutionary Anthropology: Issues, News, and Reviews Abbreviated Journal Evol. Anthropol.  
  Volume 7 Issue 3 Pages 81-96  
  Keywords variability selection; hominids; environment; adaptation; natural selection; evolution  
  Abstract Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Inc. Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN (down) 1520-6505 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5461  
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Author Linklater, W.L. doi  openurl
  Title Adaptive explanation in socio-ecology: lessons from the Equidae Type Journal Article
  Year 2000 Publication Biological Reviews of the Cambridge Philosophical Society Abbreviated Journal Biol. Rev.  
  Volume 75 Issue 1 Pages 1-20  
  Keywords *Adaptation, Physiological; Animals; Ecology; Equidae/*physiology; Female; Male; Phylogeny  
  Abstract Socio-ecological explanations for intra- and interspecific variation in the social and spatial organization of animals predominate in the scientific literature. The socio-ecological model, developed first for the Bovidae and Cervidae, is commonly applied more widely to other groups including the Equidae. Intraspecific comparisons are particularly valuable because they allow the role of environment and demography on social and spatial organization to be understood while controlling for phylogeny or morphology which confound interspecific comparisons. Feral horse (Equus caballus Linnaeus 1758) populations with different demography inhabit a range of environments throughout the world. I use 56 reports to obtain 23 measures or characteristics of the behaviour and the social and spatial organization of 19 feral horse populations in which the environment, demography, management, research effort and sample size are also described. Comparison shows that different populations had remarkably similar social and spatial organization and that group sizes and composition, and home range sizes varied as much within as between populations. I assess the few exceptions to uniformity and conclude that they are due to the attributes of the studies themselves, particularly to poor definition of terms and inadequate empiricism, rather than to the environment or demography per se. Interspecific comparisons show that equid species adhere to their different social and spatial organizations despite similarities in their environments and even when species are sympatric. Furthermore, equid male territoriality has been ill-defined in previous studies, observations presented as evidence of territoriality are also found in non-territorial equids, and populations of supposedly territorial species demonstrate female defence polygyny. Thus, territoriality may not be a useful categorization in the Equidae. Moreover, although equid socio-ecologists have relied on the socio-ecological model derived from the extremely diverse Bovidae and Cervidae for explanations of variation in equine society, the homomorphic, but large and polygynous, and monogeneric Equidae do not support previous socio-ecological explanations for relationships between body size, mating system and sexual dimorphism in ungulates. Consequently, in spite of the efforts of numerous authors during the past two decades, functional explanations of apparent differences in feral horse and equid social and spatial organization and behaviour based on assumptions of their current utility in the environmental or demographic context remain unconvincing. Nevertheless, differences in social cohesion between species that are insensitive to intra- and interspecific variation in habitat and predation pressure warrant explanation. Thus, I propose alternative avenues of inquiry including testing for species-specific differences in inter-individual aggression and investigating the role of phylogenetic constraints in equine society. The Equidae are evidence of the relative importance of phylogeny and biological structure, and unimportance of the present-day environment, in animal behaviour and social and spatial organization.  
  Address Institute of Natural Resources, Massey University, Palmerston North, New Zealand  
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  ISSN (down) 1464-7931 ISBN Medium  
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  Notes PMID:10740891 Approved no  
  Call Number Serial 2024  
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Author Ben-Shlomo, G.; Plummer, C.; Barrie, K.; Brooks, D. url  doi
openurl 
  Title Characterization of the normal dark adaptation curve of the horse Type Journal Article
  Year 2012 Publication Veterinary Ophthalmology Abbreviated Journal  
  Volume 15 Issue 1 Pages 42-45  
  Keywords adaptation; curve; dark; electroretinography; equine; scotopic  
  Abstract Objective The goal of this work is to study the dark adaptation curve of the normal horse electroretinogram (ERG). Procedures The electroretinographic responses were recorded from six healthy female ponies using a contact lens electrode and a mini-Ganzfeld electroretinographic unit. The horses were sedated intravenously with detomidine, an auriculopalpebral nerve block was then performed, and the pupil was fully dilated. The ERG was recorded in response to a low intensity light stimulus (30 mcd.s/m2) that was given at times (T) T = 5, 10, 15, 20, 25, 30, 40, 50, and 60 min of dark adaptation. Off-line analysis of the ERG was then performed. Results Mean b-wave amplitude of the full-field ERG increased continuously from 5 to 25 min of dark adaptation. The b-wave amplitude peaked at T = 25, however, there was no statistical significance between T = 20 and T = 25. The b-wave amplitude then remained elevated with no significant changes until the end of the study at T = 60 (P > 0.49). The b-wave implicit time increased continuously between T = 5 and T = 20, then gradually decreased until T = 60. No distinct a-wave was observed during the testing time. Conclusions Evaluation of horse rod function or combined rod/cone function by means of full-field ERG should be performed after a minimum 20 min of dark adaptation.  
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  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
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  ISSN (down) 1463-5224 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5626  
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