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Call J. (2004). Inferences about the location of food in the great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus). J. Comp. Psychol., 118(2), 232.
Abstract: Bonobos (Pan paniscus; n = 4), chimpanzees (Pan troglodytes; n = 12), gorillas (Gorilla gorilla; n = 8), and orangutans (Pongo pygmaeus; n = 6) were presented with 2 cups (1 baited) and given visual or auditory information about their contents. Visual information consisted of letting subjects look inside the cups. Auditory information consisted of shaking the cup so that the baited cup produced a rattling sound. Subjects correctly selected the baited cup both when they saw or heard the food. Nine individuals were above chance in both visual and auditory conditions. More important, subjects as a group selected the baited cup when only the empty cup was either shown or shaken, which means that subjects chose correctly without having seen or heard the food (i.e., inference by exclusion). Control tests showed that subjects were not more attracted to noisy cups, avoided shaken noiseless cups, or learned to use auditory information as a cue during the study. It is concluded that subjects understood that the food caused the noise, not simply that the noise was associated with the food. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Timney, B., & Keil, K. (1999). Local and global stereopsis in the horse. Vision Res, 39(10), 1861–1867.
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.
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Pepperberg, I. M., & Brezinsky, M. V. (1991). Acquisition of a relative class concept by an African gray parrot (Psittacus erithacus): discriminations based on relative size. J Comp Psychol, 105(3), 286–294.
Abstract: We report that an African gray parrot (Psittacus erithacus), Alex, responds to stimuli on a relative basis. Previous laboratory studies with artificial stimuli (such as pure tones) suggest that birds make relational responses as a secondary strategy, only after they have acquired information about the absolute values of the stimuli. Alex, however, after learning to respond to a small set of exemplars on the basis of relative size, transferred this behavior to novel situations that did not provide specific information about the absolute values of the stimuli. He responded to vocal questions about which was the larger or smaller exemplar by vocally labeling its color or material, and he responded “none” if the exemplars did not differ in size. His overall accuracy was 78.7%.
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i Rios, J. F., & Houpt, K. (1995). Sexual behavior in geldings. Appl. Anim. Behav. Sci., 46(1-2), 133–135.
Abstract: Abstract
In response to a request published in Equus, a magazine for those interested in horses, 85 owners of older geldings exhibiting sexual behavior completed history forms. The mean age of geldings was 16 f 5 years. Only 39 of the owners had had the gelding for at least a year before the behavior was noted. These cases could be used to determine the true age of onset of the problem. When log survivorship was used to determine whether there were one or two different populations, a break or change in the slope at age 16 indicated that there are two populations. One population shows the behavior from the time of castration and the other first exhibits the behavior in old age, possibly in response to an ACTH secreting pituitary adenoma. A total of 40% of the horses were Quarterhorses, the most numerous breed in the US; 78% of the horses were purebreds. Fewer than half the owners knew the age at which their horse had been castrated because they did not own the horse at the time. The mean age at castration, when known, was 3.3 f 2.5 years. The reason for contacting us was sexual behavior (70%), aggression (24%). or some other problem ( 1 o/o). Whether or not aggression was the presenting problem, most of the horses showed aggression (95%), particularly towards other geldings (88%)) but also towards people (3 1%). Copulatory behavior (mounting) was shown by 69% of the geldings and half of those were able to intromit. These findings indicate that the sexual behavior of geldings is a problem for owners and that aggression usually accompanies sexual behavior. The owners were encouraged to send serum samples taken before and after human chorionic gonadotropin (HCG) administration for testosterone and estrone sulfate analysis to determine whether residual testicular tissue was responsible for the horse’s behavior. Of the 14 horses tested, only one had elevated levels of testosterone indicating that there was residual testicular tissue. A total of six of the owners agreed to treat their horses with cyproheptadine at a dose of 8 mg day- ’ gradually increased to 88 mg day- ’ per horse. A total of three of the horses showed a decline in sexual and aggressive behavior, one got worse and two had side effects and treatment was withdrawn. |
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Hanggi, E. B. (1999). Categorization Learning in Horses (Equus caballus). J. Comp. Psychol., 113(3), 243–252.
Abstract: Categorization learning was investigated in 2 horses (Equus caballus). Both horses learned to select a 2-dimensional black stimulus with an open center instead of a filled stimulus in a 2-choice discrimination task. After a criterion of 10 out of 10 correct responses in a random series for 2 consecutive sessions was reached, 15 additional pairs of open-center versus filled stimuli were tested. Each was run to criterion and then incorporated into sessions of randomly mixed problems. Both horses solved the 1st problem by simple pattern discrimination and showed evidence of categorical processing for subsequent problems. New pairs were learned with few or no errors, and correct responses on novel trials were significantly above chance. These results suggest that the horses were making their selections on the basis of shared characteristics with the training stimuli and were using categorization skills in problem solving.
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Bartosova, J., Dvorakova, R., Vancatova, M., & Svobodova, I. (2008). Comprehension of human pointing gesture in domestic horses: Effect of training method. In IESM 2008.
Abstract: Horses have been considered to rely on human gesticular cues (McKinley and Sambrook 2000, Anim Cogn 3:13-22; and recently Maros et al. 2008, Anim Cogn 11:457-466), however large variability among individuals tested in two-ways object choice tasks was found. Part of the horses in those studies (40 and 26 %, respectively) even failed to pass adequately through the training session which preceded the testing phase and served to learn a horse to carry out a task. Therefore, we alternated the experimental design designed by McKinley and Sambrook (reduced number of testing trials to 10 per horse to keep its attention, applied just one, a dynamic-sustained pointing cue with touching the bucket, etc.), and tested an effect of training method, sex, age, and learning on proportion of correct choices. We hypothesised, that horses trained by “traditional” method (TTM) will get lower score than those experienced with “horsemanship-based” methods (HTM), being characterized by closer and more frequent human-horse contact and also extended exercising “from the ground” with frequent using of arms cues. Despite simplification of the methods, only about 60 % of tested horses passed through the training phase (i.e., learned to come to and upturn the bucket with hidden treat). Successful completion of training phase was reached regardless of age or sex of a horse, but by the training method; HTM horses ran better compared to TTM ones. No significant effect of age, sex, or learning (i.e., trial order within all 10), and training method as well was found on proportion of correct trials in the testing phase. Horses made a correct choice in more than 70% of trials. Individual scores ranged from 50 to 100 %. In conclusion, horses showed high level of comprehension of human pointing gesture, regardless of their sex or age. No effects of training method or learning process within a test suggest low impact of handling and learning on the level of comprehension at least of the most vivid human pointing gesture. Horses trained by methods based on “natural human-horse communication” did enhance cooperation with people.
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König, H. E., Wissdorf, H., Probst, A., Macher, R., Voß, S., & Polsterer, E. (2005). Considerations about the function of the mimic muscles and the vomeronasal organ of horses during the Flehmen reaction. Pferdeheilkunde, 21(4), 297–300.
Abstract: Additional to the olfactory epithelium, the equine vomeronasal organ serves to the perception of odorous substances and specially for pheromones. In a middle-size horse this organ has an extension in length from an imaginary transverse plane about 10 cm caudally the nostrils to a transverse plane through the middle of the second premolar tooth. During the Flehmen reaction the levator labii superior, nasolabial, caninus and lateralis nasi muscles contract. The upper lip and the tip of the nose are lifted. The opening of the nostrils is narrowed, caused by the convergence of the plate and horn of the alar cartilage. In this manner in case of Flehmen reaction air is directly conducted towards the opening of the vomeronasal organ into the nasal cavity during inspiration. During the “Flehmen” horses assume a characteristic posture.
Keywords: Anatomy; Behaviour; Flehmen reaction; Horse; Vomeronasal organ
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Bates, L. A., Sayialel, K. N., Njiraini, N. W., Poole, J. H., Moss, C. J., & Byrne, R. W. (2008). African elephants have expectations about the locations of out-of-sight family members. Biol Lett, 4(1), 34–36.
Abstract: Monitoring the location of conspecifics may be important to social mammals. Here, we use an expectancy-violation paradigm to test the ability of African elephants (Loxodonta africana) to keep track of their social companions from olfactory cues. We presented elephants with samples of earth mixed with urine from female conspecifics that were either kin or unrelated to them, and either unexpected or highly predictable at that location. From behavioural measurements of the elephants' reactions, we show that African elephants can recognize up to 17 females and possibly up to 30 family members from cues present in the urine-earth mix, and that they keep track of the location of these individuals in relation to themselves.
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Cregier, S., & Holmes, O. (2008). The Welfare of Horses During Transport. In IESM 2008.
Abstract: Standard horse trailers, adapted from dead-weight delivery wagons, were never intended to carry live weight. Horse magazines and scientific, veterinary, animal behaviour, and engineering journals indicate the consequences: scrambling, trailer sway, equipment damage, loss of tow vehicle control, jack knifing, rollovers, and injuries to horses, handlers, and rescuers. The standard horse trailer cannot meet motor vehicle regulations requiring trailers to halt within 9 metres (30 feet) at 32 kilometres (20 miles) per hour without jack knifing. Equipment intended to protect the horse in transit adds to travel hazards. University of Guelph Ontario Veterinary Clinic surgeons report that head, throat, chest, shattered shoulder blades, butt bar or chain injuries to hocks and legs, and pastern injuries, in that order, are common. Internal, back, and hindquarter injuries also result due to the horse“s forced high-headed, wider hindleg stance or falling during transport. The horse”s sacroiliac joint, not intended to be weight bearing, is easily dislocated by pathologists. This is why for centuries horsemen have released tension from horses“ backs and necks by ”showing them the way to the ground.“ It was Italian cavalryman Federico Caprilli”s forward seat which removed strain on the horse“s hindquarters and freed its head to balance. More demanding jumps, slides and races were possible. Today, only two horse transport designs allow the horse to balance automatically and naturally during transit. Strain on the horse”s hindquarters is removed. These transports, adapted to equine behavioural needs, meet Office International des Epizooties (OIE) standards for handler and horse safety and welfare, and automotive safety. Japanese and U.S. studies on performance horses transported according to OIE standards have indicated that these horses have a competitive advantage. Applying these standards allows a horseman to complete a journey with the same horse that began it.
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Houpt, K. A. (2008). Maternal behavior in horses. In IESM 2008.
Abstract: Mares quickly form a bond with their foals, probably within the first hour. They lick the foal usually beginning at the tail end, then the head and later the body of the foal. Licking behavior disappears within the first hours in most mares. Once the bond is formed the mare will let no other foal nurse and stays within a meter of the foal most of the time during the first week. The foal follows her when awake, but when he sleeps she stands over him. As the foal matures the distance the mare maintains from the foals get longer and she may graze as he sleeps. The bond of the mother to the foal gradually weakens as revealed by her response to separation from the foal. Weaning usually takes place shortly before the birth of the next foal. Some mares will attempt to steal foals and this can lead to injury of either the mares or the foal. Because of the strong and exclusive bond of most mares to their foal, foal rejection is especially abnormal. It occurs in some breeds more frequently than others, indicating a heritable component. Arabian mares reject 5% of their foals and other breeds reject less than 2%. There are three types of foal rejection- simple fear of the foal that can be quickly solved by holding the mare so the foal can suckle. The mare learns that nursing is pleasurable. This process usually takes only a few hours of holding the mare because foals suckle so frequently- about four times an hours. The second form of foal rejection is avoidance of tactile stimulation of the inguinal fold. When the foal attempts to suckle he usually strikes that skin fold and causes the mare to cow kick and move away. Desensitization to stimulation of the inguinal fold can solve this problem in a few hours. Treatment is more complex and longer for mares that are aggressive to the foal even when it does not touch them. This type of foal rejection can be treated with drugs that inhibit dopamine such as acepromazine-not the alpha adrenergic agent xylazine. Dopamine inhibits the pituitary hormone prolactin, a putative maternal hormone, which increases milk production. Blocking dopamine will increase prolactin. The mare should always have visual contact with the foal, but be restrained so she can not bite or kick the foal. A pole across the stall confining the mare against a wall is best. Maternal behavior can be induced in non-pregnant mares using injections of estrogen, progesterone, and the dopamine inhibitor sulpiride. Once lactation begins cervical stimulation can be used to elicit maternal behavior toward the next foal the mare sees.
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