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Author (up) Levy, J.
Title The mammalian brain and the adaptive advantage of cerebral asymmetry Type Journal Article
Year 1977 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci
Volume 299 Issue Pages 264-272
Keywords *Adaptation, Physiological; Adaptation, Psychological/physiology; Animals; Behavior, Animal/physiology; Brain/*physiology; Cognition/physiology; Dominance, Cerebral/*physiology; *Evolution; Humans; Intelligence; Perception/physiology
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 0077-8923 ISBN Medium
Area Expedition Conference
Notes PMID:280207 Approved no
Call Number Equine Behaviour @ team @ Serial 4137
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Author (up) Linklater, W.L.
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
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 1464-7931 ISBN Medium
Area Expedition Conference
Notes PMID:10740891 Approved no
Call Number Serial 2024
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Author (up) Young, L.E.; Rogers, K.; Wood, J.L.N.
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
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 8750-7587 ISBN Medium
Area Expedition Conference
Notes PMID:15920096 Approved no
Call Number Equine Behaviour @ team @ Serial 3768
Permanent link to this record