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Author Marc, M.; Parvizi, N.; Ellendorff, F.; Kallweit, E.; Elsaesser, F. openurl 
  Title Plasma cortisol and ACTH concentrations in the warmblood horse in response to a standardized treadmill exercise test as physiological markers for evaluation of training status Type Journal Article
  Year (up) 2000 Publication Journal of Animal Science Abbreviated Journal J. Anim Sci.  
  Volume 78 Issue 7 Pages 1936-1946  
  Keywords Adrenocorticotropic Hormone/*blood/diagnostic use; Animals; Catheterization/veterinary; Exercise Test; Horses/*blood; Hydrocortisone/*blood; Male; *Physical Conditioning, Animal  
  Abstract Reliable physiological markers for performance evaluation in sport horses are missing. To determine the diagnostic value of plasma ACTH and cortisol measurements in the warmblood horse, 10 initially 3-yr-old geldings of the Hannovarian breed were either exposed to a training schedule or served as controls. During experimental Phase 1, horses were group-housed, and half of the horses were trained for 20 wk on a high-speed treadmill. During Phase 2, groups were switched and one group was trained for 10 wk as during Phase 1, whereas the control group was confined to boxes. During Phase 3 horses were initially schooled for riding. Thereafter, all horses were regularly schooled for dressage and jumping, and half of the horses received an additional endurance training for 24 wk. During all phases horses were exposed at regular intervals to various standardized treadmill exercise tests. During and after the tests frequent blood samples were taken from an indwelling jugular catheter for determination of ACTH and cortisol. Treadmill exercise increased both hormones. Maximum ACTH concentrations were recorded at the end of exercise, and maximum cortisol levels were recorded 20 to 30 min later. Except for one test there were no differences in ACTH levels between trained horses and controls. There was no significant effect of training on the cortisol response (net increase) to treadmill exercise in any of the tests during Phase 1. During Phase 2 higher cortisol responses were recorded in controls than in trained horses (P < .05) after 10 wk of training (controls confined to boxes). During Phase 3 plasma cortisol responses were also higher in controls than in trained horses (P < .05 after 6, 18, and 24, P < or = .07 after 12 wk of training) when the inclination of the treadmill was 5%, but not at 3%. There was no overlap in net cortisol responses at 30 min between trained and untrained horses. An ACTH application after 24 wk of training resulted in higher cortisol responses in controls than in trained horses (P < or = .05), without any overlap between the groups at 30 min after ACTH. Plasma cortisol responses to either treadmill exercise or ACTH injection may be a reliable physiological marker for performance evaluation. Prerequisites are sufficient differences in training status and sufficient intensity of exercise test conditions.  
  Address Institute of Animal Science and Animal Behaviour, Federal Agricultural Research Center (FAL) Mariensee, Neustadt, Germany  
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  Series Volume Series Issue Edition  
  ISSN 0021-8812 ISBN Medium  
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  Notes PMID:10907837 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3732  
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Author Emery, N.J. doi  openurl
  Title The eyes have it: the neuroethology, function and evolution of social gaze Type Journal Article
  Year (up) 2000 Publication Neuroscience and Biobehavioral Reviews Abbreviated Journal Neurosci Biobehav Rev  
  Volume 24 Issue 6 Pages 581-604  
  Keywords Animals; *Eye; Fixation, Ocular; Humans; *Social Behavior  
  Abstract Gaze is an important component of social interaction. The function, evolution and neurobiology of gaze processing are therefore of interest to a number of researchers. This review discusses the evolutionary role of social gaze in vertebrates (focusing on primates), and a hypothesis that this role has changed substantially for primates compared to other animals. This change may have been driven by morphological changes to the face and eyes of primates, limitations in the facial anatomy of other vertebrates, changes in the ecology of the environment in which primates live, and a necessity to communicate information about the environment, emotional and mental states. The eyes represent different levels of signal value depending on the status, disposition and emotional state of the sender and receiver of such signals. There are regions in the monkey and human brain which contain neurons that respond selectively to faces, bodies and eye gaze. The ability to follow another individual's gaze direction is affected in individuals with autism and other psychopathological disorders, and after particular localized brain lesions. The hypothesis that gaze following is “hard-wired” in the brain, and may be localized within a circuit linking the superior temporal sulcus, amygdala and orbitofrontal cortex is discussed.  
  Address Center for Neuroscience, Department of Psychiatry & California Regional Primate Research Center, University of California, Davis, CA 95616, USA. njemery@ucdavis.edu  
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  Series Volume Series Issue Edition  
  ISSN 0149-7634 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:10940436 Approved no  
  Call Number refbase @ user @ Serial 3996  
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Author Jezierski T., Gorecka A. openurl 
  Title Changes in the horses heart rate during different levels of social isolation Type Journal Article
  Year (up) 2000 Publication Animal Science Papers and Reports Abbreviated Journal Anim. Sci. Pap. Rep.  
  Volume 18 Issue 1 Pages 33-41  
  Keywords horse; heart rate; human-animal relation  
  Abstract Social isolation in horses may be regarded as a stress factor which implies welfare problems. The aim of the experiment was to examine the effect of different levels of transient social isolation and human presence on the heart rate (HR) in horses. Seven horses were used and the experiment was conducted in a tether-stable without boxes. The HR was recorded electronically, continuously for 40 min during the following test situations: all horses in the stable; experimenter approaches the tested horse, other horses being untied and leaving the stable; tested horse staying alone or in the company of one or two stable-mates; the experimenter attempts to calm the isolated horse; outdoor auditory stimuli from other horses. The HR was significantly higher during the whole period of isolation, and depended on how many horses were left as company for the one tested. The highest HR was observed while other horses were leaving the stable and during perception of outdoor auditory stimuli from others. When in the company of two stable mates, the HR was elevated only while other horses were leaving the stable and during auditory stimuli from outdoors. Human presence evoked a significant increase in HR, probably due to conditioning of horses (expecting to be untied and allowed to join the others), irrespectively whether the tested horse was left alone or with one or two stable-mates.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4816  
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Author Johnstone, R.A.; Dugatkin, L.A. url  doi
openurl 
  Title Coalition formation in animals and the nature of winner and loser effects Type Journal Article
  Year (up) 2000 Publication Proceedings of the Royal Society B: Biological Sciences Abbreviated Journal Proc. Roy. Soc. Lond. B Biol. Sci.  
  Volume 267 Issue 1438 Pages 17-21  
  Keywords  
  Abstract Coalition formation has been documented in a diverse array of taxa, yet there has been little formal analysis of polyadic interactions such as coalitions. Here, we develop an optimality model which examines the role of winner and loser effects in shaping coalition formation. We demonstrate that the predicted patterns of alliances are strongly dependent on the way in which winner and loser effects change with contestant strength. When winner and loser effects decrease with the resource-holding power (RHP) of the combatants, coalitions will be favoured between the strongest members of a group, but not between the weakest. If, in contrast, winner and loser effects increase with RHP, exactly the opposite predictions emerge. All other things being equal, intervention is more likely to prove worthwhile when the beneficiary of the aid is weaker (and its opponent is stronger), because the beneficiary is then less likely to win without help. Consequently, intervention is more probable when the impact of victory on the subsequent performance of a combatant increases with that individual's strength because this selects for intervention in favour of weaker combatants. The published literature on hierarchy formation does not reveal how winner and loser effects actually change with contestant strength and we therefore hope that our model will spur others to collect such data; in this light we suggest an experiment which will help to elucidate the nature of winner and loser effects and their impact on coalition formation in animals.  
  Address * aggression * dominance * hierarchy * intervention * reciprocity  
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  Notes 10.1098/rspb.2000.0960 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5290  
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Author Merl, S.; Scherzer, S.; Palme, R.; Möstl, E. url  doi
openurl 
  Title Pain causes increased concentrations of glucocorticoid metabolites in horse feces Type Journal Article
  Year (up) 2000 Publication Journal of Equine Veterinary Science Abbreviated Journal J Equine Vet Sci  
  Volume 20 Issue 9 Pages 586-590  
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  Abstract The concentration of 11,17-dioxoandrostanes (11,17-DOA), a group of cortisol metabolites, was measured using enzyme immunoassay in fecal samples of horses experiencing painful episodes. One group of horses consisted of 10 stallions castrated (samples were collected daily for 10 days); the other group was made up of 29 horses which were brought to an animal hospital because of signs of colic (samples were collected twice daily for six days). Before castration, median concentrations of 10.5 nmol/kg feces were measured. On days 1 and 2 after castration, median 11,17-DOA values increased up to 26.2 and 50.0 nmol/kg feces, respectively, and decreased thereafter to levels lower than at the beginning of the sampling period. High variations were measured between individual cases of colic. In animals with colic, all horses excreted more than 33 nmol 11,17-DOA/kg feces for various periods. The highest concentration measured was 885 nmol/kg feces. One animal out of the 29 colic horses did not show any clinical signs of pain upon arrival in the hospital. The 11,17-DOA values were below 17 nmol/kg feces in all those samples. From this data we conclude, that the concentration of 11,17-DOA in feces is a parameter for painful situations that have occurred one or two days earlier.  
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  ISSN 0737-0806 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6047  
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Author Houpt, K.; Marrow, M.; Seeliger, M. url  doi
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  Title A preliminary study of the effect of music on equine behavior Type Journal Article
  Year (up) 2000 Publication Journal of Equine Veterinary Science Abbreviated Journal  
  Volume 20 Issue 11 Pages 691-737  
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  ISSN 0737-0806 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6633  
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Author Visser, E.K.; van Reenen, C.G.; Hopster, H.; Schilder, M.B.H.; Knaap, J.H.; Barneveld, A.; Blokhuis, H.J. url  doi
openurl 
  Title Quantifying aspects of young horses' temperament: consistency of behavioural variables Type Journal Article
  Year (up) 2001 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 74 Issue 4 Pages 241-258  
  Keywords Horses; Temperament; Individual differences; Behavioural variables; Pca  
  Abstract Performance of horses, whether in sports or in leisure, depends on both physical abilities as well as temperament. The aim of the present work was to measure individual variation and consistency of behavioural variables, related to temperament, in young horses of the same breed and age, and reared under controlled housing conditions and management. A total of 41 Dutch Warmblood horses were tested at 9, 10, 21 and 22 months of age in two behavioural tests, i.e. the novel object test and the handling test. In the novel object test horses were confronted with an open umbrella that was lowered from the ceiling. In the handling test horses were led by a human to cross a bridge. Per test, behavioural variables in the following behavioural classes were observed: locomotor activity, latency times, postural expressions and vocalisations. Within years, all behavioural variables in the handling test, and all but two in the novel object test were positively correlated (0.36<Rs<0.81, P<0.05). For both tests, at 9, 10, 21 and 22 months of age, a principal component analysis (PCA) was carried out to examine whether there were indications for underlying components of these individual behavioural variables that could possibly serve as measures for temperamental traits. The first component in the novel object test could be regarded as `flightiness' and the second as `sensitiveness'. In the handling test, the first component was suggested to relate to `patience', the second component to `willingness to perform'. The temperamental trait `flightiness' (novel object test) as well as the temperamental trait `patience' (handling test) were positively correlated within both years (0.36<Rs<0.65, P<0.05). For the traits `sensitiveness' (novel object test) and `willingness to perform' (handling test) a positive correlation was only found within the first year (0.44<Rs<0.57, P<0.01). A few individual behavioural variables showed consistency over years. Additionally, just one out of four temperamental traits, namely `flightiness', proved to be consistent over years (Rs=0.49, P<0.01). The temperamental trait `patience' showed a trend between years (Rs=0.31, 0.05<P<0.1). It is concluded that the behavioural tests employed in the present study can be used to reliably identify individual behavioural variables and temperamental traits in young horses. Long-term consistency, i.e. between subsequent years, could not be demonstrated convincingly. Nevertheless, future work may indicate that employing the same approach and considering an even longer time period or different phases of the horse's life, long-term consistency does exist.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 324  
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Author Clutton-Brock, T.H.; Russell, A.F.; Sharpe, L.L.; Brotherton, P.N.; McIlrath, G.M.; White, S.; Cameron, E.Z. doi  openurl
  Title Effects of helpers on juvenile development and survival in meerkats Type Journal Article
  Year (up) 2001 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 293 Issue 5539 Pages 2446-2449  
  Keywords Animals; Breeding; Carnivora/growth & development/*physiology; *Cooperative Behavior; Feeding Behavior; Female; Male; Survival Rate; *Weight Gain  
  Abstract Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. thcb@hermes.cam.ac.uk  
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  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
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  Notes PMID:11577235 Approved no  
  Call Number refbase @ user @ Serial 414  
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Author Johnstone, R.A. doi  openurl
  Title Eavesdropping and animal conflict Type Journal Article
  Year (up) 2001 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 98 Issue 16 Pages 9177-9180  
  Keywords *Aggression; Animals; *Behavior, Animal; *Conflict (Psychology); Models, Theoretical  
  Abstract Fights between pairs of animals frequently take place within a wider social context. The displays exchanged during conflict, and the outcome of an encounter, are often detectable by individuals who are not immediately involved. In at least some species, such bystanders are known to eavesdrop on contests between others, and to modify their behavior toward the contestants in response to the observed interaction. Here, I extend Maynard Smith's well known model of animal aggression, the Hawk-Dove game, to incorporate the possibility of eavesdroppers. I show that some eavesdropping is favored whenever the cost of losing an escalated fight exceeds the value of the contested resource, and that its equilibrium frequency is greatest when costs are relatively high. Eavesdropping reduces the risk of escalated conflict relative to that expected by chance, given the level of aggression in the population. However, it also promotes increased aggression, because it enhances the value of victory. The net result is that escalated conflicts are predicted to occur more frequently when eavesdropping is possible.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom. raj1003@hermes.cam.ac.uk  
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  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
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  Notes PMID:11459936 Approved no  
  Call Number refbase @ user @ Serial 497  
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Author Peake, T.M.; Terry, A.M.; McGregor, P.K.; Dabelsteen, T. doi  openurl
  Title Male great tits eavesdrop on simulated male-to-male vocal interactions Type Journal Article
  Year (up) 2001 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 268 Issue 1472 Pages 1183-1187  
  Keywords Animals; Male; Songbirds/*physiology; *Vocalization, Animal  
  Abstract Animal communication generally occurs in the environment of a network of several potential signallers and receivers. Within a network environment, it is possible to gain relative information about conspecifics by eavesdropping on signalling interactions. We presented male great tits with the opportunity to gain such information by simulating singing interactions using two loudspeakers. Interactions were presented so that relevant information was not available in the absolute singing behaviour of either individual, only in the relative timing of their songs in the interaction as a whole. We then assayed the information extracted by focal males by subsequently introducing one of the 'interactants' (i.e. loudspeakers) into the territory of the focal male. Focal males responded with a reduced song output to males that had just 'lost' an interaction. Focal males did not respond significantly differently to 'winners' as compared with intruders recently involved in an interaction that contained no consistent information. Focal males also responded by switching song types more often when encountering males that had recently been involved in a low-intensity interaction. These results provide the clearest evidence yet that male songbirds extract information from signal interactions between conspecifics in the field.  
  Address Department of Animal Behaviour, Zoological Institute, Tagensvej 16, University of Copenhagen, 2200 Copenhagen N, Denmark. tmpeake@zi.ku.dk  
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  ISSN 0962-8452 ISBN Medium  
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  Notes PMID:11375107 Approved no  
  Call Number refbase @ user @ Serial 712  
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