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Author Lau, A.N.; Peng, L.; Goto, H.; Chemnick, L.; Ryder, O.A.; Makova, K.D. url  doi
openurl 
  Title Horse Domestication and Conservation Genetics of Przewalski's Horse Inferred from Sex Chromosomal and Autosomal Sequences Type Journal Article
  Year 2009 Publication Mol Biol Evol Abbreviated Journal Mol Biol Evol  
  Volume 26 Issue 1 Pages 199-208  
  Keywords  
  Abstract Despite their ability to interbreed and produce fertile offspring, there is continued disagreement about the genetic relationship of the domestic horse (Equus caballus) to its endangered wild relative, Przewalski's horse (Equus przewalskii). Analyses have differed as to whether or not Przewalski's horse is placed phylogenetically as a separate sister group to domestic horses. Because Przewalski's horse and domestic horse are so closely related, genetic data can also be used to infer domestication-specific differences between the two. To investigate the genetic relationship of Przewalski's horse to the domestic horse and to address whether evolution of the domestic horse is driven by males or females, five homologous introns (a total of [~]3 kb) were sequenced on the X and Y chromosomes in two Przewalski's horses and three breeds of domestic horses: Arabian horse, Mongolian domestic horse, and Dartmoor pony. Five autosomal introns (a total of [~]6 kb) were sequenced for these horses as well. The sequences of sex chromosomal and autosomal introns were used to determine nucleotide diversity and the forces driving evolution in these species. As a result, X chromosomal and autosomal data do not place Przewalski's horses in a separate clade within phylogenetic trees for horses, suggesting a close relationship between domestic and Przewalski's horses. It was also found that there was a lack of nucleotide diversity on the Y chromosome and higher nucleotide diversity than expected on the X chromosome in domestic horses as compared with the Y chromosome and autosomes. This supports the hypothesis that very few male horses along with numerous female horses founded the various domestic horse breeds. Patterns of nucleotide diversity among different types of chromosomes were distinct for Przewalski's in contrast to domestic horses, supporting unique evolutionary histories of the two species.  
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  Call Number Equine Behaviour @ team @ Serial 4997  
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Author King, A.J.; Cowlishaw, G. url  openurl
  Title Leaders, followers and group decision-making Type Journal Article
  Year 2009 Publication Communicative & Integrative Biology Abbreviated Journal Commun Integr Biol  
  Volume 2 Issue 2 Pages 147-150  
  Keywords  
  Abstract Social animals have to make a multitude of group decisions on a daily basis. At the most basic level, this will involve coordination of activities and travel directions. In groups of insects, birds and fish, much of this 'coordination' can be the result of relatively simple interaction patterns among group members. Such systems are self-organizing, and often do not require specific leaders, or followers. However, in more socially complex groups, achieving collective group action-a consensus-may not be accomplished by simple rules alone. Instead, a consensus may be reached by the averaging of preferences (democracy), or by following the choices of specific leaders (despotism). In this mini-review, we discuss the conditions necessary for despotism in animal groups, and focus upon new studies investigating coordinated actions in primates. We ask how specific leaders arise and why others follow them-providing new insight into the mechanisms of effective leadership in groups characterized by strong social relationships.  
  Address Institute of Zoology; Zoological Society of London; London, UK  
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  Language English Summary Language Original Title  
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  ISSN 1942-0889 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19513268 Approved yes  
  Call Number Equine Behaviour @ team @ Serial 4998  
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Author Gosden, T. P.; Svensson, E. I. url  doi
openurl 
  Title Density-Dependent Male Mating Harassment, Female Resistance, and Male Mimicry Type Journal Article
  Year 2009 Publication The American Naturalist Abbreviated Journal Am Nat  
  Volume 173 Issue 6 Pages 709-721  
  Keywords tolerance, sexual conflict, path analysis, mating behavior, polymorphism, fecundity.  
  Abstract Abstract:

Genetic variation in female resistance and tolerance to male mating harassment can affect the outcome of sexually antagonistic mating interactions. We investigated female mating rates and male mating harassment in natural populations of a damselfly (Ischnura elegans). This damselfly species has a heritable sex‐limited polymorphism in females, where one of the morphs is a male mimic (androchrome females). The three female morphs differ in mating rates, and these differences are stable across populations and years. However, the degree of premating resistance toward male mating attempts varied across generations and populations. Male mating harassment of the female morphs changed in a density‐dependent fashion, suggesting that male mate preferences are plastic and vary with the different morph densities. We quantified morph differences in male mating harassment and female fecundity, using path analysis and structural equation modeling. We found variation between the morphs in the fitness consequences of mating, with the fecundity of one of the nonmimetic morphs declining with increasing male mating harassment. However, androchrome females had lower overall fecundity, presumably reflecting a cost of male mimicry. Density‐dependent male mating harassment on the morphs and fecundity costs of male mimicry are thus likely to contribute to the maintenance of this female polymorphism.
 
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  Call Number Equine Behaviour @ team @ Serial 4999  
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Author Bhadra, A.; Jordán, F.; Sumana, A.; Deshpande, S.A.; Gadagkar, R. url  doi
openurl 
  Title A comparative social network analysis of wasp colonies and classrooms: Linking network structure to functioning Type Journal Article
  Year 2009 Publication Ecological Complexity Abbreviated Journal Ecol Complex  
  Volume 6 Issue 1 Pages 48-55  
  Keywords Social insect; Ropalidia; Centrality; Small world  
  Abstract A major question in current network science is how to understand the relationship between structure and functioning of real networks. Here we present a comparative network analysis of 48 wasp and 36 human social networks. We have compared the centralisation and small world character of these interaction networks and have studied how these properties change over time. We compared the interaction networks of (1) two congeneric wasp species (Ropalidia marginata and Ropalidia cyathiformis), (2) the queen-right (with the queen) and queen-less (without the queen) networks of wasps, (3) the four network types obtained by combining (1) and (2) above, and (4) wasp networks with the social networks of children in 36 classrooms. We have found perfect (100%) centralisation in a queen-less wasp colony and nearly perfect centralisation in several other queen-less wasp colonies. Note that the perfectly centralised interaction network is quite unique in the literature of real-world networks. Differences between the interaction networks of the two wasp species are smaller than differences between the networks describing their different colony conditions. Also, the differences between different colony conditions are larger than the differences between wasp and children networks. For example, the structure of queen-right R. marginata colonies is more similar to children social networks than to that of their queen-less colonies. We conclude that network architecture depends more on the functioning of the particular community than on taxonomic differences (either between two wasp species or between wasps and humans).  
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  ISSN 1476-945x ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5003  
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Author Albright, J.D.; Mohammed, H.O.; Heleski, C.R.; Wickens, C.L.; Houpt, K.A. url  doi
openurl 
  Title Crib-biting in US horses: Breed predispositions and owner perceptions of aetiology Type Journal Article
  Year 2009 Publication Equine Veterinary Journal Abbreviated Journal  
  Volume 41 Issue 5 Pages 455-458  
  Keywords HORSE; BEHAVIOUR; CRIB-BITING; BREED PREVALENCE; LEARNING  
  Abstract Reasons for performing study: Crib-biting is an equine stereotypy that may result in diseases such as colic. Certain breeds and management factors have been associated.

Objectives: To determine: breed prevalence of crib-biting in US horses; the likelihood that one horse learns to crib-bite from another; and owner perceptions of causal factors.

Methods: An initial postal survey queried the number and breed of crib-biting horses and if a horse began after being exposed to a horse with this habit. In a follow-up survey, a volunteer subset of owners was asked the number of affected and nonaffected horses of each breed and the extent of conspecific contact. The likelihood of crib-biting given breed and extent of contact was quantified using odds ratio (OR) and significance of the association was assessed using the Chi-squared test.

Results: Overall prevalence was 4.4%. Thoroughbreds were the breed most affected (13.3%). Approximately half of owners believed environmental factors predominantly cause the condition (54.4%) and crib-biting is learned by observation (48.8%). However, only 1.0% of horses became affected after being exposed to a crib-biter. The majority (86%) of horses was turned out in the same pasture with other horses and extent of contact with conspecifics was not statistically related to risk.

Conclusion: This is the first study to report breed prevalence for crib-biting in US horses. Thoroughbreds were the breed more likely to be affected. More owners believed either environmental conditions were a predominant cause or a combination of genetic and environmental factors contributes to the behaviour. Only a small number of horses reportedly began to crib-bite after being exposed to an affected individual, but approximately half of owners considered it to be a learned behaviour; most owners did not isolate affected horses.

Potential relevance: Genetic predisposition, not just intensive management conditions and surroundings, may be a factor in the high crib-biting prevalence in some breeds, and warrants further investigation. Little evidence exists to suggest horses learn the behaviour from other horses, and isolation may cause unnecessary stress.
 
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  Call Number Equine Behaviour @ team @ Serial 5010  
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Author Whitehead, H. doi  openurl
  Title SOCPROG programs: analysing animal social structures Type Journal Article
  Year 2009 Publication Behavioral Ecology and Sociobiology Abbreviated Journal Behav. Ecol. Sociobiol.  
  Volume 63 Issue 5 Pages 765-778  
  Keywords Social analysis – Software – Association  
  Abstract Abstract  SOCPROG is a set of programs which analyses data on animal associations. Data usually come from observations of the social behaviour of individually identifiable animals. Associations among animals, sampling periods, restrictions on the data and association indices can be defined very flexibly. SOCPROG can analyse data sets including 1,000 or more individuals. Association matrices are displayed using sociograms, principal coordinates analysis, multidimensional scaling and cluster analyses. Permutation tests, Mantel and related tests and matrix correlation methods examine hypotheses about preferred associations among individuals and classes of individual. Weighted network statistics are calculated and can be tested against null hypotheses. Temporal analyses include displays of lagged association rates (rates of reassociation following an association). Models can be fitted to lagged association rates. Multiple association measures, including measures produced by other programs such as genetic or range use data, may be analysed using Mantel tests and principal components analysis. SOCPROG also performs mark-recapture population analyses and movement analyses. SOCPROG is written in the programming language MATLAB and may be downloaded free from the World Wide Web.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5026  
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Author Uller, C.; Lewis, J. doi  openurl
  Title Horses (Equus caballus) select the greater of two quantities in small numerical contrasts Type Journal Article
  Year 2009 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 12 Issue 5 Pages 733-738  
  Keywords Quantity representation – Horses – Number discrimination  
  Abstract Abstract  The ability to select the greater numerosity over another in small sets seems to stem from the calculation of which set contains more, and has been taken as evidence of a primordial representation at the roots of the primate numerical system. We tested 56 horses (Equus caballus) in a paradigm previously used with human infants and nonhuman primates. Horses saw two quantities paired in contrasts—2 versus 1, 3 versus 2, 6 versus 4 and a control for volume, 2 versus 1 big—and had to make a choice by snout touching the container holding the numerosity selected. The horses spontaneously selected the greater of the two quantities when the numerosities were small. These results add to evidence showing spontaneous quantity assessment in a variety of species.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5028  
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Author Lemasson, A.; Boutin, A.; Boivin, S.; Blois-Heulin, C.; Hausberger, M. doi  openurl
  Title Horse (Equus caballus) whinnies: a source of social information Type Journal Article
  Year 2009 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 12 Issue 5 Pages 693-704  
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  Abstract Abstract  Many animal species that rely mainly on calls to communicate produce individual acoustic structures, but we wondered whether individuals of species better known as visual communicants, with small vocal repertoires, would also exhibit individual distinctiveness in calls. Moreover, theoretical advances concerning the evolution of social intelligence are usually based on primate species data, but relatively little is known about the social cognitive capacities of non-primate mammals. However, some non-primate species demonstrate auditory recognition of social categories and possess mental representation of their social network. Horses (Equus caballus) form stable social networks and although they display a large range of visual signals, they also use long-distance whinny calls to maintain contact. Here, we investigated the potential existence of individual acoustic signatures in whinny calls and the ability of horses to discriminate by ear individuals varying in their degree of familiarity. Our analysis of the acoustic structure of whinnies of 30 adult domestic horses (ten stallions, ten geldings, ten mares) revealed that some of the frequency and temporal parameters carried reliable information about the caller’s sex, body size and identity. However, no correlations with age were found. Playback experiments evaluated the behavioural significance of this variability. Twelve horses heard either control white noise or whinnies emitted by group members, familiar neighbours or unfamiliar horses. While control sounds did not induce any particular response, horses discriminated the social category of the callers and reacted with a sound-specific behaviour (vigilance and attraction varied with familiarity). Our results support the existence of social knowledge in horses and suggest a process of vocal coding/decoding of information.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5035  
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Author Ramseyer, A.; Boissy, A.; Thierry, B.; Dumont, B. doi  openurl
  Title Individual and social determinants of spontaneous group movements in cattle and sheep Type Journal Article
  Year 2009 Publication animal Abbreviated Journal Animal  
  Volume 3 Issue 09 Pages 1319-1326 M3 - 10.1017/S1751731109004790  
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  Abstract Group-living animals travel together to collectively exploit the resources of their environment. This study investigates how social relationships and individual temperament traits affect movement orders in domestic cattle and sheep. We analysed spontaneous group movements occurring at pasture after a resting period in a group of 15 18-month-old Charolais heifers and a group of 19 1-year-old Romane ewe-lambs. For each species, animals had similar social experience and no kinship ties. Before that, animals were observed within the group to establish their social status (e.g. dominance and preferential relationships, and sociability), then in individual tests in order to assess their emotional traits. In both species, most individuals could initiate a group movement but some individuals were more successful than others in recruiting the rest of the group. Ewe-lambs, and to a lesser extent heifers, held preferential positions during travel. We did not find any significant correlations in either species between animal order and their position in the dominance hierarchy (heifers: P = 0.438; ewe-lambs: P = 0.574) while individuals linked by preferential bonds frequently followed each other during group movements (heifers: P < 0.001; ewe-lambs: P < 0.001). With regard to social traits, heifers with a low cohesion index, and with a lower number of partners with whom they develop frequent affinitive interactions, acted more frequently as ‘first movers’ (P = 0.040 and 0.023, respectively), as well as did ewe-lambs with a high spatial independency index (P = 0.002). Ewe-lambs with the highest cohesion indices were more frequently observed in front of the group while moving halfway between departure and arrival (P = 0.028). We did not find significant correlations between individual positions during group movements and emotional traits such as reactivity, boldness and fearfulness. We conclude that preferential bonds and individual traits related to social dependence were more influential in spontaneous group movements at pasture than were emotional traits and dominance status.  
  Address group movement; group order; social relationship; temperament; ungulates  
  Corporate Author Thesis  
  Publisher Cambridge Journals Online Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 1751-7311 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5047  
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Author Hanggi, E.B.; Ingersoll, J.F. doi  openurl
  Title Stimulus discrimination by horses under scotopic conditions Type Journal Article
  Year 2009 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 82 Issue 1 Pages 45-50  
  Keywords Discrimination learning; Equine; Horse; Night vision; Scotopic vision  
  Abstract Scotopic vision in horses (Equus caballus) was investigated using behavioral measurements for the first time. Four horses were tested for the ability to make simple visual discriminations of geometric figures (circles and triangles) under various brightness levels within an enclosed building. Measurements of brightness ranging from 10.37 to 24.12 magnitudes per square arcsecond (mag/arcsec2; in candelas per square meter--7.70 to 2.43E-05 cd/m2) were taken using a Sky Quality Meter. These values approximated outdoor conditions ranging from twilight in open country to a dark moonless night in dense forest. The horses were able to solve the discrimination problems in all brightness settings up to 23.77 mag/arcsec2 (3.35E-05 cd/m2). Moreover, they easily navigated their way around obstacles located within the testing area in extremely dim light (>23.50 mag/arcsec2; 4.30E-05 cd/m2), which were in conditions too dark for the human experimenters to see. These findings support physiological data that reveal a rod-dominated visual system as well as observations of equine activity at night.  
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  ISSN 0376-6357 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5051  
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