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Author (down) Vlasak, A.N. doi  openurl
  Title Global and local spatial landmarks: their role during foraging by Columbian ground squirrels (Spermophilus columbianus) Type Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 1 Pages 71-80  
  Keywords Animals; Cues; Feeding Behavior/*psychology; Female; *Memory; Mental Recall; Orientation; Sciuridae/*psychology; *Space Perception; *Spatial Behavior  
  Abstract Locating food and refuge is essential for an animal's survival. However, little is known how mammals navigate under natural conditions and cope with given environmental constraints. In a series of six experiments, I investigated landmark-based navigation in free-ranging Columbian ground squirrels (Spermophilus columbianus). Squirrels were trained individually to find a baited platform within an array of nine identical platforms and artificial landmarks set up on their territories. After animals learned the location of the food platform in the array, the position of the latter with respect to local artificial, local natural, and global landmarks was manipulated, and the animal's ability to find the food platform was tested. When only positions of local artificial landmarks were changed, squirrels located food with high accuracy. When the location of the array relative to global landmarks was altered, food-finding accuracy decreased but remained significant. In the absence of known global landmarks, the presence of a familiar route and natural local landmarks resulted in significant but not highly accurate performance. Squirrels likely relied on multiple types of cues when orienting towards a food platform. Local landmarks were used only as a secondary mechanism of navigation, and were not attended to when a familiar route and known global landmarks were present. This study provided insights into landmark use by a wild mammal in a natural situation, and it demonstrated that an array of platforms can be employed to investigate landmark-based navigation under such conditions.  
  Address Biology Department, University of Pennsylvania, Philadelphia, PA 19104, USA. avlasak@sas.upenn.edu  
  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 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16163480 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2483  
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Author (down) Vlamings, P.H.J.M.; Uher, J.; Call, J. doi  openurl
  Title How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) perform on the reversed contingency task: the effects of food quantity and food visibility Type Journal Article
  Year 2006 Publication Journal of Experimental Psychology. Animal Behavior Processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 32 Issue 1 Pages 60-70  
  Keywords Age Factors; Animals; Behavior, Animal/physiology; Cognition; Conditioning (Psychology); Female; *Food; Gorilla gorilla/*psychology; *Learning; Male; Pan paniscus/*psychology; Pan troglodytes/*psychology; Pongo pygmaeus/*psychology; *Visual Perception  
  Abstract S. T. Boysen and G. G. Berntson (1995) found that chimpanzees performed poorly on a reversed contingency task in which they had to point to the smaller of 2 food quantities to acquire the larger quantity. The authors compared the performance of 4 great ape species (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) on the reversed contingency task while manipulating food quantity (0-4 or 1-4) and food visibility (visible pairs or covered pairs). Results showed no systematic species differences but large individual differences. Some individuals of each species were able to solve the reversed contingency task. Both quantity and visibility of the food items had a significant effect on performance. Subjects performed better when the disparity between quantities was smaller and the quantities were not directly visible.  
  Address Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. p.vlamings@psychology.unimaas.nl  
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  Series Volume Series Issue Edition  
  ISSN 0097-7403 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16435965 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2765  
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Author (down) Visser, E.K.; Van Reenen, C.G.; Rundgren, M.; Zetterqvist, M.; Morgan, K.; Blokhuis, H.J. openurl 
  Title Responses of horses in behavioural tests correlate with temperament assessed by riders Type Journal Article
  Year 2003 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 35 Issue 2 Pages 176-183  
  Keywords Adult; Animals; *Behavior, Animal/physiology; Data Interpretation, Statistical; Female; *Handling (Psychology); Heart Rate/*physiology; Horses/physiology/*psychology; Humans; Male; Personality; Temperament/*physiology  
  Abstract REASONS FOR PERFORMING STUDY: Behavioural tests as well as observers' ratings have been used to study horses' temperament. However, the relationship between the ratings and the responses in behavioural tests has not yet been studied in detail. OBJECTIVES: The aim of the present study was to examine this relationship between ratings and responses. METHODS: Eighteen mature Swedish Warmblood horses were subjected to 2 behavioural tests, one relating to novelty (novel object test) and one to handling (handling test). Subsequently, 16 of these horses were ridden by 16 equally experienced students, having no former experience with the horses. Immediately after each ride, the students scored the horse for 10 temperamental traits using a line rating method. RESULTS: It was shown that for each temperamental trait all 16 riders agreed on the ranking of the horses (0.212<W<0.505, P < 0.001). CONCLUSIONS: Correlations between behavioural and heart rate variables in the behavioural tests revealed that horses with a high level of locomotion or much restlessness behaviour exhibited high mean heart rate and low heart rate variability. In particular, heart rate variables in the behavioural tests were found to correlate with riders' rating scores. Furthermore, the underlying components of the handling test, retrieved with a principal component analysis (PCA) correlated with riders' rating scores while the underlying components of the novel object test did not. POTENTIAL CLINICAL RELEVANCE: It is concluded that it is possible for a large panel of assessors to agree upon a horse's temperament and that objective measures from behavioural tests correlate significantly with temperamental traits assessed by a panel of assessors.  
  Address Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, PO Box 80.163, NL-3508 TD Utrecht, The Netherlands  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12638795 Approved no  
  Call Number Serial 1906  
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Author (down) Viscido, S.V.; Miller, M.; Wethey, D.S. openurl 
  Title The dilemma of the selfish herd: the search for a realistic movement rule Type Journal Article
  Year 2002 Publication Journal of theoretical biology Abbreviated Journal J. Theor. Biol.  
  Volume 217 Issue 2 Pages 183-194  
  Keywords Animals; *Behavior, Animal; *Mass Behavior; Models, Biological; *Motor Activity; Predatory Behavior  
  Abstract The selfish herd hypothesis predicts that aggregations form because individuals move toward one another to minimize their own predation risk. The “dilemma of the selfish herd” is that movement rules that are easy for individuals to follow, fail to produce true aggregations, while rules that produce aggregations require individual behavior so complex that one may doubt most animals can follow them. If natural selection at the individual level is responsible for herding behavior, a solution to the dilemma must exist. Using computer simulations, we examined four different movement rules. Relative predation risk was different for all four movement rules (p<0.05). We defined three criteria for measuring the quality of a movement rule. A good movement rule should (a) be statistically likely to benefit an individual that follows it, (b) be something we can imagine most animals are capable of following, and (c) result in a centrally compact flock. The local crowded horizon rule, which allowed individuals to take the positions of many flock-mates into account, but decreased the influence of flock-mates with distance, best satisfied these criteria. The local crowded horizon rule was very sensitive to the animal's perceptive ability. Therefore, the animal's ability to detect its neighbors is an important factor in the dynamics of group formation.  
  Address Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA. viscido@u.washington.edu  
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  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:12202112 Approved no  
  Call Number refbase @ user @ Serial 554  
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Author (down) Viscido, S.V.; Miller, M.; Wethey, D.S. doi  openurl
  Title The response of a selfish herd to an attack from outside the group perimeter Type Journal Article
  Year 2001 Publication Journal of theoretical biology Abbreviated Journal J. Theor. Biol.  
  Volume 208 Issue 3 Pages 315-328  
  Keywords Animals; *Behavior, Animal; *Computer Simulation; Models, Biological; *Movement; Predatory Behavior  
  Abstract According to the selfish herd hypothesis, animals can decrease predation risk by moving toward one another if the predator can appear anywhere and will attack the nearest target. Previous studies have shown that aggregations can form using simple movement rules designed to decrease each animal's Domain of Danger. However, if the predator attacks from outside the group's perimeter, these simple movement rules might not lead to aggregation. To test whether simple selfish movement rules would decrease predation risk for those situations when the predator attacks from outside the flock perimeter, we constructed a computer model that allowed flocks of 75 simulated fiddler crabs to react to one another, and to a predator attacking from 7 m away. We attacked simulated crab flocks with predators of different sizes and attack speeds, and computed relative predation risk after 120 time steps. Final trajectories showed flight toward the center of the flock, but curving away from the predator. Path curvature depended on the predator's size and approach speed. The average crab experienced a greater decrease in predation risk when the predator was small or slow moving. Regardless of the predator's size and speed, however, predation risk always decreased as long as crabs took their flock-mates into account. We conclude that, even when flight away from an external predator occurs, the selfish avoidance of danger can lead to aggregation.  
  Address Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, U.S.A. viscido@u.washington.edu  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0022-5193 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11207093 Approved no  
  Call Number refbase @ user @ Serial 555  
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Author (down) Virga, V.; Houpt, K.A. openurl 
  Title Prevalence of placentophagia in horses Type Journal Article
  Year 2001 Publication Equine veterinary journal Abbreviated Journal Equine Vet J  
  Volume 33 Issue 2 Pages 208-210  
  Keywords Animals; *Behavior, Animal; Colic/epidemiology/*veterinary; Exploratory Behavior; *Feeding Behavior; Female; Horse Diseases/*epidemiology; Horses; Incidence; New York/epidemiology; *Placenta; Postpartum Period; Pregnancy; Prevalence; Questionnaires  
  Abstract  
  Address Animal Behavior Clinic, Cornell University Hospital for Animals, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11266073 Approved no  
  Call Number refbase @ user @ Serial 31  
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Author (down) Virányi, Z.; Topál, J.; Miklósi, Á.; Csányi, V. doi  openurl
  Title A nonverbal test of knowledge attribution: a comparative study on dogs and children Type Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 1 Pages 13-26  
  Keywords Animals; *Child Psychology; Child, Preschool; Cues; Dogs/*psychology; Female; Humans; Male; Nonverbal Communication; *Problem Solving; Species Specificity  
  Abstract The sensitivity of eleven pet dogs and eleven 2.5-year-old children to others' past perceptual access was tested for object-specificity in a playful, nonverbal task in which a human Helper's knowledge state regarding the whereabouts of a hidden toy and a stick (a tool necessary for getting the out-of-reach toy) was systematically manipulated. In the four experimental conditions the Helper either participated or was absent during hiding of the toy and the stick and therefore she knew the place(s) of (1) both the toy and the stick, (2) only the toy, (3) only the stick or (4) neither of them. The subjects observed the hiding processes, but they could not reach the objects, so they had to involve the Helper to retrieve the toy. The dogs were more inclined to signal the place of the toy in each condition and indicated the location of the stick only sporadically. However the children signalled both the location of the toy and that of the stick in those situations when the Helper had similar knowledge regarding the whereabouts of them (i.e. knew or ignored both of them), and in those conditions in which the Helper was ignorant of the whereabouts of only one object the children indicated the place of this object more often than that of the known one. At the same time however, both dogs and children signalled the place of the toy more frequently if the Helper had been absent during toy-hiding compared to those conditions when she had participated in the hiding. Although this behaviour appears to correspond with the Helper's knowledge state, even the subtle distinction made by the children can be interpreted without a casual understanding of knowledge-formation in others.  
  Address Department of Ethology, ELTE University Budapest, Pazmany P. setany 1/C H-1117, Hungary. zsofi.viranyi@freemail.hu  
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  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:15895261 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2486  
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Author (down) Virányi, Z.; Topál, J.; Gácsi, M.; Miklósi, Á.; Csányi, V. url  doi
openurl 
  Title Dogs respond appropriately to cues of humans' attentional focus Type Journal Article
  Year 2004 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 66 Issue 2 Pages 161-172  
  Keywords Animals; *Attention; Bonding, Human-Pet; Communication; *Cues; Dogs; Humans; Recognition (Psychology)  
  Abstract Dogs' ability to recognise cues of human visual attention was studied in different experiments. Study 1 was designed to test the dogs' responsiveness to their owner's tape-recorded verbal commands (Down!) while the Instructor (who was the owner of the dog) was facing either the dog or a human partner or none of them, or was visually separated from the dog. Results show that dogs were more ready to follow the command if the Instructor attended them during instruction compared to situations when the Instructor faced the human partner or was out of sight of the dog. Importantly, however, dogs showed intermediate performance when the Instructor was orienting into 'empty space' during the re-played verbal commands. This suggests that dogs are able to differentiate the focus of human attention. In Study 2 the same dogs were offered the possibility to beg for food from two unfamiliar humans whose visual attention (i.e. facing the dog or turning away) was systematically varied. The dogs' preference for choosing the attentive person shows that dogs are capable of using visual cues of attention to evaluate the human actors' responsiveness to solicit food-sharing. The dogs' ability to understand the communicatory nature of the situations is discussed in terms of their social cognitive skills and unique evolutionary history.  
  Address Department of Ethology, Eotvos Lorand University, Budapest, Hungary. zsofi.viranyi@freemail.hu  
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  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
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  Notes PMID:15110918 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4957  
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Author (down) Villani, M.; Cairoli, F.; Kindahl, H.; Galeati, G.; Faustini, M.; Carluccio, A.; Veronesi, M.C. doi  openurl
  Title Effects of mating on plasma concentrations of testosterone, cortisol, oestrone sulphate and 15-ketodihydro-PGF2alpha in stallions Type Journal Article
  Year 2006 Publication Reproduction in Domestic Animals = Zuchthygiene Abbreviated Journal Reprod Domest Anim  
  Volume 41 Issue 6 Pages 544-548  
  Keywords Animals; Dinoprost/*analogs & derivatives/blood; Ejaculation/physiology; Estrone/*analogs & derivatives/blood; Horses/*blood/physiology; Hydrocortisone/*blood; Male; Sexual Behavior, Animal/*physiology; Testosterone/*blood  
  Abstract Very little information is available regarding the physiological mechanisms involved in the normal sexual activity in the stallion and, in particular, the endocrine control of reproduction is still not clearly understood. This experiment was designed to determine the short-term effect of sexual stimulation on plasma concentrations of testosterone, cortisol, oestrone sulphate and 15-ketodihydro-PGF(2alpha) in stallions. Semen samples were collected from 10 lighthorse stallions of proven fertility using a Missouri model artificial vagina. At the same time, blood samples were collected from the jugular vein with heparinized tubes, 20 and 10 min before oestrous mare exposure, at exposure and 10, 20, 30 min after dismounting. Testosterone concentrations showed a sharp rise 10 min after mating (p < 0.001), reached a plateau, and then showed a further increase 30 min after mating (p < 0.001). Cortisol concentrations increased 10 min after mating (p < 0.001) and remained at high levels in the subsequent samples taken. A peak of oestrone sulphate was observed 10 min after mating (p < 0.001). 15-Ketodihydro-PGF(2alpha) concentrations decreased rapidly at the moment of the exposure of the stallions to an oestrous mare (p < 0.05), returned to pre-mating concentrations and then decreased again 30 min after mating (p < 0.05).  
  Address Dipartimento di Scienze Cliniche Veterinarie, Sez. Clinica Ostetrica e Ginecologica Veterinaria, Milan, Italy  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0936-6768 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17107515 Approved no  
  Call Number Serial 1855  
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Author (down) Vermeulen, A.D.; Evans, D.L. openurl 
  Title Measurements of fitness in thoroughbred racehorses using field studies of heart rate and velocity with a global positioning system Type Journal Article
  Year 2006 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl  
  Volume Issue 36 Pages 113-117  
  Keywords Animals; Female; Geographic Information Systems; Heart Rate/*physiology; Horses/*physiology; Male; Physical Conditioning, Animal/*physiology; Physical Fitness/*physiology; Running/physiology  
  Abstract REASONS FOR PERFORMING STUDY: Field based studies of changes in fitness are difficult to conduct in galloping Thoroughbreds. Measurements of heart rate (HR) and real time velocity with a global positioning system (GPS) could provide a method for routine field studies of fitness. OBJECTIVE: To investigate measurements of fitness in the field without using multiple, standardised steps of increasing velocity in the exercise test. METHODS: Twelve healthy 3- to 5-year-old Thoroughbreds were used in the study of reliability, and twelve 2-year-old Thoroughbreds in the investigation of the effect of training. Five second averages of velocity and HR were recorded during a typical fast exercise training session, using a GPS and Polar HR monitor. A standardised exercise test protocol was not used. Regression analyses using trot and gallop data were used to calculate velocities at HR of 200 beats/min (V200), and at maximal HR (VHRmax). Data were collected on consecutive 'fast' day training sessions to assess the reliability of measurements. The effect of training was investigated with fitness tests in weeks 2 and 6 of 'fast' training. Absolute and relative differences were calculated to evaluate reliability, and paired t tests were used to detect an effect of training. RESULTS: VHRmax, V200 and HRmax were reliable measurements of fitness, with mean differences of 2% or less. Reliability of VHRmax was not dependent on VHRmax. VHRmax and V200 both increased significantly with training (P<0.01), but there was no effect of training on HRmax. There were no significant changes in the slope or intercept of the regression equations after training. CONCLUSIONS: Velocity and HR measurements during field gallop exercise provided reliable measures of fitness which enabled a measurement of the response to training. POTENTIAL RELEVANCE: This approach offers a simple, noninvasive method for monitoring adaptations to training in the field.  
  Address Faculty of Veterinary Science, The University of Sydney, New South Wales 2006, Australia  
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  Notes PMID:17402404 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4013  
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