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Author Harman, A.M.; Moore, S.; Hoskins, R.; Keller, P. doi  openurl
  Title (up) Horse vision and an explanation for the visual behaviour originally explained by the 'ramp retina' Type Journal Article
  Year 1999 Publication Equine veterinary journal Abbreviated Journal Equine Vet J  
  Volume 31 Issue 5 Pages 384-390  
  Keywords Animals; Behavior, Animal; Cell Count; Eye/*anatomy & histology; Ganglia, Sensory/cytology; Horses/*physiology; Refractive Errors/veterinary; Retina/cytology/*physiology; Vision/*physiology; Visual Acuity; Visual Fields  
  Abstract Here we provide confirmation that the 'ramp retina' of the horse, once thought to result in head rotating visual behaviour, does not exist. We found a 9% variation in axial length of the eye between the streak region and the dorsal periphery. However, the difference was in the opposite direction to that proposed for the 'ramp retina'. Furthermore, acuity in the narrow, intense visual streak in the inferior retina is 16.5 cycles per degree compared with 2.7 cycles per degree in the periphery. Therefore, it is improbable that the horse rotates its head to focus onto the peripheral retina. Rather, the horse rotates the nose up high to observe distant objects because binocular overlap is oriented down the nose, with a blind area directly in front of the forehead.  
  Address Department of Psychology, University of Western Australia, Nedlands, Australia  
  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 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:10505953 Approved no  
  Call Number refbase @ user @ Serial 836  
Permanent link to this record
 

 
Author Hanggi, E.B.; Ingersoll, J.F. url  doi
openurl 
  Title (up) Lateral vision in horses: A behavioral investigation Type Journal Article
  Year 2012 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 91 Issue 1 Pages 70-76  
  Keywords Lateral vision; Horse; Equine; Stimulus discrimination; Field of view; Peripheral  
  Abstract This study investigated lateral vision in horses (Equus caballus) for the first time from a behavioral point of view. Three horses were tested using a novel experimental design to determine the range of their lateral and caudolateral vision with respect to stimulus detection and discrimination. Real-life stimuli were presented along a curvilinear wall in one of four different positions (A, B, C, D) and one of two height locations (Top, Bottom) on both sides of the horse. To test for stimulus detection, the correct stimulus was paired against a control; for stimulus discrimination, the correct stimulus was paired against another object. To indicate that the correct stimulus was detected or discriminated, the horses pushed one of two paddles. All horses scored significantly above chance on stimulus detection trials regardless of stimulus position or location. They also accurately discriminated between stimuli when objects appeared in positions A, B, and C for the top or bottom locations; however, they failed to discriminate these stimuli at position D. This study supports physiological descriptions of the equine eye and provides new behavioral data showing that horses can detect the appearance of objects within an almost fully encompassing circle and are able to identify objects within most but not all of their panoramic field of view.  
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  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5621  
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Author Mech L.D. url  openurl
  Title (up) Leadership in Wolf, Canis lupus, Packs. Type Journal Article
  Year 2000 Publication Canadian Field-Naturalist Abbreviated Journal Can Field Nat  
  Volume 114 Issue 2 Pages 259-263  
  Keywords Wolf, Canis lupus, leadership, behavior, foraging, movements, pup care, provisioning, sociality, reproduction, breeding, Northwest Territories.  
  Abstract I examine leadership in Wolf (Canis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4688  
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Author Kilian, A.; Fersen, L. von; Güntürkün, O. url  doi
openurl 
  Title (up) Left hemispheric advantage for numerical abilities in the bottlenose dolphin Type Journal Article
  Year 2005 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 68 Issue 2 Pages 179-184  
  Keywords Bottlenose dolphin; Hemispheric specialization; Monocular vision; Numerical ability  
  Abstract In a two-choice discrimination paradigm, a bottlenose dolphin discriminated relational dimensions between visual numerosity stimuli under monocular viewing conditions. After prior binocular acquisition of the task, two monocular test series with different number stimuli were conducted. In accordance with recent studies on visual lateralization in the bottlenose dolphin, our results revealed an overall advantage of the right visual field. Due to the complete decussation of the optic nerve fibers, this suggests a specialization of the left hemisphere for analysing relational features between stimuli as required in tests for numerical abilities. These processes are typically right hemisphere-based in other mammals (including humans) and birds. The present data provide further evidence for a general right visual field advantage in bottlenose dolphins for visual information processing. It is thus assumed that dolphins possess a unique functional architecture of their cerebral asymmetries.  
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  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5366  
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Author Timney, B.; Keil, K. doi  openurl
  Title (up) Local and global stereopsis in the horse Type Journal Article
  Year 1999 Publication Vision Research Abbreviated Journal Vision Res  
  Volume 39 Issue 10 Pages 1861-1867  
  Keywords Animals; Depth Perception/*physiology; Female; Horses/*physiology; Pattern Recognition, Visual/physiology; Psychophysics; Sensory Thresholds/physiology; Vision, Binocular/physiology; Vision, Monocular/physiology  
  Abstract Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocular thresholds averaged about 15 min arc. In the second experiment we obtained evidence for the presence of global stereopsis by testing the animals' ability to discriminate between random-dot stereograms with and without consistent disparity information. When presented with such stimuli they showed a strong preference for the cyclopean equivalent of the positive stimulus with the real depth. These results provide the first behavioral demonstration of a full range of stereoscopic skills in a lateral-eyed mammal.  
  Address Department of Psychology, Faculty of Social Science, University of Western Ontario, London, Canada. timney@julian.uwo.ca  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0042-6989 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:10343877 Approved yes  
  Call Number Equine Behaviour @ team @ Serial 3580  
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Author Macuda, T.; Timney, B. url  openurl
  Title (up) Luminance and chromatic discrimination in the horse (Equus caballus) Type Journal Article
  Year 1999 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 44 Issue 3 Pages 301-307  
  Keywords Colour vision; Chromatic discrimination; Luminance discrimination; Horse  
  Abstract Equine colour vision was measured under conditions that minimised the possibility of animals using brightness cues to make chromatic discriminations. In a two-stage study, we first obtained luminance discrimination functions for achromatic targets then tested for chromatic discrimination over a range of target luminances. Horses were trained on a two-choice discrimination task. The positive stimulus was varied in luminance and/or colour using neutral density and broad band colour filters. The negative stimulus appeared as a uniform grey. In the brightness discrimination task, the horses performed well at large luminance differences but their percentage of correct responses declined to near chance levels at differences of less than 0.2 log units. In addition, a decrement in performance was noted at luminance differences of less than 0.2 log units for green and yellow chromatic discrimination functions, suggesting that horses cannot easily discriminate yellow and green from grey. However, the chromatic discrimination functions for red and blue showed that animals performed very well across the full range of target luminances. These results suggest that horses are at least dichromats.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 844  
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Author Adler, L.L.; Adler, H.E. url  doi
openurl 
  Title (up) Ontogeny of observational learning in the dog (Canis familiaris) Type Journal Article
  Year 1977 Publication Developmental Psychobiology Abbreviated Journal Dev Psychobiol  
  Volume 10 Issue 3 Pages 267-271  
  Keywords Animals; Dogs/*physiology; Female; Learning/*physiology; Male; Vision, Ocular/physiology  
  Abstract A split-litter technique was used to test observational learning in 4 litters of Miniature Dachshund puppies, 21, 28, 38, and 60 days old at the beginning of the experiment. In one side of a duplicate cage, one puppy of a litter, the demonstrator, learned to pull in a food cart on a runner by means of a ribbon, while another puppy, the observer, watched from an adjacent compartment, separated by a wire screen. Observational learning was demonstrated by the saving in time for the 1st trial when the observer was given the same problem to solve. Maturation, particularly the development of visual function and motor coordination, set a lower age limit for the emergence of observational learning.  
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  Series Volume Series Issue Edition  
  ISSN 0012-1630 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:863122 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5186  
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Author Bartoš, L.; Bartošová, J.; Starostová, L. url  doi
openurl 
  Title (up) Position of the head is not associated with changes in horse vision Type Journal Article
  Year 2008 Publication Equine Veterinary Journal Abbreviated Journal  
  Volume 40 Issue 6 Pages 599-601  
  Keywords horse; horse vision; head position; pupil rotation  
  Abstract It has become accepted that the horse cannot see directly in front when the nose is lowered and must therefore rely on the rider. We tested the hypothesis that this conclusion would be correct only if the horse did not adjust the eyeball horizontal axis to changes of the head position. The results of the present study suggest that it is unlikely that horses have limited vision in relation to their head position when driven by the rider, and that the horse maintains the optimal horizontal eyeball position regardless of head position relative to the ground.  
  Address  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2042-3306 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5679  
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Author Anderson, J.R. doi  openurl
  Title (up) Self-recognition in dolphins: credible cetaceans; compromised criteria, controls, and conclusions Type Journal Article
  Year 1995 Publication Consciousness and Cognition Abbreviated Journal Conscious Cogn  
  Volume 4 Issue 2 Pages 239-243  
  Keywords Animal Communication; Animals; *Awareness; Discrimination Learning; Dolphins/*psychology; Female; Male; Orientation; *Self Concept; Social Behavior; *Television; *Visual Perception  
  Abstract  
  Address Laboratoire de Psychophysiologie, CNRS URA 1295, Universite Louis Pasteur, Strasbourg, France  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1053-8100 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8521263 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4163  
Permanent link to this record
 

 
Author Loveland, K.A. doi  openurl
  Title (up) Self-recognition in the bottlenose dolphin: ecological considerations Type Journal Article
  Year 1995 Publication Consciousness and Cognition Abbreviated Journal Conscious Cogn  
  Volume 4 Issue 2 Pages 254-257  
  Keywords Animals; Attention; *Awareness; Body Image; Dolphins/*psychology; Exploratory Behavior; Female; Male; *Self Concept; *Social Environment; Species Specificity; Television; *Visual Perception  
  Abstract  
  Address Department of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston 77025, USA  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 1053-8100 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8521267 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4161  
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