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Timney, B. (2008). Photopic Spectral Sensitivity and Wavelength Discrimination in the Horse (Equus caballus). In IESM 2008.
Abstract: A number of studies have demonstrated that horses have chromatic vision and are able to distinguish colours from grey, independent of brightness. Anatomical and physiological data support the view that they are dichromats. In two experiments we provide behavioural evidence for their dichromacy. In the first we measured photopic spectral sensitivity. Using a spatial two alternative forced choice task, two horses were required to discriminate a coloured circular patch on an achromatic background from a blank field over a range of wavelengths . The obtained spectral sensitivity function was consistent with the presence of two cone classes with predicted spectral peaks at 429 nm and 545 nm, respectively. In the second experiment we obtained wavelength discrimination functions. The same animals were required to make discriminations between a series of standard wavelengths and a series of comparison wavelengths across the spectrum. The resultant wavelength discrimination function showed a single minimum at approximately 480 nm, which is also consistent with the view that horses are dichromats. Key Words: Horse, colour vision, spectral sensitivity, wavelength discrimination
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Takimoto, A., & Fujita, K. (2008). Are horses (Equus caballus) sensitive to human attentional states? In IESM 2008.
Abstract: The ability to reliably detect what others are attending to seems important for social species to interact with their partners. Domestic horses (Equus caballus) have lived with humans for over five thousand years, hence they might have developed sensitivity to human attention. In the present study, we investigated whether horses would discriminate the situation in which a human experimenter could see them from the situation in which she could not. Specifically, we tested whether horses understand the role of eyes in human attentional states, produce more visual gestures when the experimenter can see their begging behaviors and produce more auditory or tactile gestures when she can not. We used with a slight modification the paradigm that previously yielded support for chimpanzee understanding of human attention (Hostetter et al. 2007). Twelve horses were offered food by the experimenter who showed various attentional states in front of them. We scored frequency of begging behaviors by the horses. In experiment 1, we set three kinds of condition: hand over the eyes, hand over the mouth and away. In the last condition there was only a food in front of horses, which was a control condition. The results showed that horses produced more auditory or tactile begging behaviors when the experimenter“s eyes were not visible than when her eyes were visible, but there was no difference in visual begging behaviors. In experiment 2, we set two kinds of condition: eyes closed and eyes open. The horses also produced more auditory or tactile begging behaviors when the experimenter”s eyes were closed than when they were open. However, there was no difference in visual begging behaviors. These results show that horses discriminate the situation in which humans can see from that in which humans can not. Of special interest, horses increased only auditory or tactile behaviors, not all types of communicative behaviors, when the experimenter could not see their begging behaviors. This result suggests that horses are sensitive to human attentional states. Moreover, horses may do recognize the eyes as an important indicator of whether or not humans will respond to their behavior and they may be able to behave flexibly depending upon human attentional states
Keywords: Horses; Attentional state; Begging behavior
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Søndergaard, E., & Turner, K. C. (2008). Timeframe for a novel horse to become familiar in a group. In IESM 2008.
Abstract: The case of familiarity in equine husbandry is not a topic that has suffered vast amounts of examination. During their lifetime domestic horses will most likely experience multiple changes in their social environment such as being sold, moved, and sent to training amongst other things. In recent years a considerable amount of studies have shown the benefits of group-housing on horses, and familiarity timeframes are of genuine importance in management of such systems.
It is our intension to determine the timeframe a novel horse faces before it is recognized as being familiar in an already established group, what factors are of importance and the level of injuries sustained in the introduction period. 24 2-year old Danish Warmblood fillies were used for this study in two blocks of 12 horses. The familiar horses, titled the K-group, consisted of 16 horses and the U-group, the unfamiliar horses, of 8. The horses came from different studs to ensure no prior contact between the two groups of test animals. They were all raised in stable group-housing systems and thereby accustomed to social interactions between conspecifics. Prior to pairing the K-horses up, nearest-neighbour observations was performed in the holding paddock to ensure the two horses were in fact familiar and would act as an established group. 8 groups of 3 individuals, 2 familiar and 1 unfamiliar, were held in separate paddocks measuring 80x80m. The horses were within eyesight of the other groups but were not able to have any physical contact. Behavioural observations were performed for 20 minutes per group upon letting the U-horse enter, and then for one hour per group (3x20mins) every Monday, Wednesday and Friday the following 16 days. On day 0, 1, 2, 4, 8 and 16 they were tested for individual preference within the group, and on test day 1 and 16 any injuries sustained were also noted. Dominance rank within the groups was determined by a group-feeding test on the last day of observation. Preliminary results from the first block indicate an overall timeframe of 6-7 days for familiarity to develop, established by observational data such as fading of greeting behaviour and decrease in distance between the three horses in the respective groups. It was also indicated that aggression between horses in the groups is not determined by familiarity but by dominance rank. Results from the full experiment will be presented. |
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Stupperich, A., & Strack, M. (2008). Interaction with horses (equus): Assessment with a circumplex based questionnaire. In IESM 2008.
Abstract: According to Interpersonal Theory every interaction is motivated by efforts to achieve and maintain self-esteem and to avoid anxiety. People"s characteristic ways of accomplishing these ends are called interpersonal reflexes. Those interpersonal reflexes are evident in interaction with animals, since they are determined by the interpersonal traits of personality. We wanted to catch the typical interpersonal reflexes in between humans and horses compared to pet animals.
We used the self rating assessment instrument “Inventory of Problematic Interactions with Animals” (IPI – Animals), which bases on a Interpersonal Circumplex Model (Human Animal Circumplex; HAC) and was constructed to catch specific dispositions of distress caused by animals using two dimensions (too dominant vrs too submissive and too warm versus too cold). Data of 233 male adolescents (93 of them actual pet owners, from that 12 horse owners) were collected. We found that different pet preferences holds distinct locations in the HAC. Horse persons differ from dog and cat persons within the dimension dominance (dog: chi2(df126) =161.54 p= .018; cat: chi2(df126) =199.95 p= .045). Persons, who own a horse or would wish to own one, describe themselves as dominant, but warm interactors. They report that they want horses to notice them. They tend do too much for them and behave very effusively with them. On the other hand they feel that the animal takes too much advantage of the relationship. |
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Streit,, S., Zeitler-Feicht, M. H., & Dempfle, L. (2008). Automatic feeding systems versus feeding stalls for horses kept in groups: visiting frequency, stress situations and risk of injury. In IESM 2008.
Abstract: When keeping horses in run-out sheds, feeding stalls are usually recommended for individual feeding; which allows equine typical simultaneous eating. However, automatic feeding devices for hay and concentrates are being increasingly used, and these do not allow simultaneous eating. This research aims to compare visiting frequency, stress situations, and the risk of injury, in the area of automatic feeding systems with those at feeding stalls. The studies were carried out at 10 stables with feeding stalls and at 11 with automatic feeding systems for hay and concentrates. These stables were otherwise similar regarding the keeping of the horses and the management of the facilities. Each group consisted of 8 to 21 horses, with 260 horses taking part in total. Every group was observed for 6 sessions, each of 4 hours. These 6 sessions together made 24 hours, a complete day.
Horses in stables with feeding stalls visited the feeding area (waiting area, the station, exit area) 45.5 ± 27.3 times on average in 24 hours, and in stables with automatic feeders for hay and concentrates, 93.1 ± 53.5 times. This difference was significant. Threatening behaviour, without risk of injury or with risk of injury, occurred significantly more frequently in stables with automatic feeders (9.6 ± 12.9 times and 4.2 ± 5.5 times respectively per 24 hours and horse) than in stables with feeding stalls (6.0 ± 10.4 times and 1.5 ± 3.3 times respectively per 24 hours and horse). The management of the stable, however, proved to have its most important influence on the behaviour of the horses. Displacement activities were observed in stables with feeding stalls 0.3 ± 1.0 times per horse and 24 hours and in stables with automatic feeders for hay and concentrate 12.9 ± 23.3 times. Situations that could cause either stress or injuries to the horses occurred in stables with feeding stalls within 24 hours per horse only 3.7 ± 13.1 and 1.3 ± 4.8 times on average respectively. Such situations were to be seen in stables with automatic feeder 17.0 ± 33.4 and 8.6 ± 15.3 times respectively per horse and 24 hours – clearly more often. We may therefore conclude that the more often the feeding area is visited, the more frequently threatening gestures without and with risk of injury occur. The same goes for the number of situations that may result in stress or injuries. Therefore to sum up it can be said that feeding in feedings stalls leads to less risk of stress and injuries compared with feeding by computer controlled systems. On the other hand, computer controlled systems have the advantage of stimulating the horses to move, which is very important for their health. While assessing this study it should be taken into account that there were very big individual differences between the horses. The result of the statistical evaluation was that the management of the stable has a decisive influence on the observed features. Therefore both feeding systems can be recommended, especially as the number of conflicts in the feeding area in all stables was relatively low and no injuries were observed in connection with the feeding. |
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Schmidt, A., Möstl, E., Neuhauser, S., Aurich, J., Müller, J., & Aurich, C. (2008). Changes in heart rate and cortisol release during initial training of three-year-old warmblood sport horse stallions. In IESM 2008.
Abstract: The first weeks of training in young sport horses have been suggested to represent a stressful period and training practises for horses have been questioned recently. So far, only limited data on the stress response of young horses to the initial training are available. Heart rate (HR) provides information on fitness of the horse but is also an indicator of stress or pain. Determination of cortisol metabolites in faeces is a non-invasive technique to determine a prolonged stress response. In our study, three-year-old warmblood sport horse stallions (n=8) were followed through a standardised 10-week classical training programme from lunging to first mounting of a rider and progressing to moderate work. Feed, housing and management were similar for all horses. HR was recorded with a mobile recording System (f810i, Polar, Kempele, Finland) fixed to a girth around the thorax of the horse and was monitored twice weekly from 30 min before to 30 min after training, i.e. including the training period. In addition, cortisol concentrations were determined in faecal samples collected three times daily. Overall basal HR before daily training was 39±2 (SEM) beats/min and mean values did not change significantly over the 10-week study period. Average HR during initial lunging (week 1) was 119±14 beats min and decreased to 95±5 beats/min in week 2. Due to individual variations this decrease did not reach statistical significance. Neither first mounting of a rider (89±10 beats/min) nor an increasing workload (e.g. week 8: 111±4 beats/min) were associated with prolonged increases in mean HR, but transient increases were recorded and the response to mounting of the rider differed markedly between stallions. After daily training, HR decreased rapidly but was slightly, although significantly (p<0.05, Friedman-test) higher than pre-work values (46±2 beats/min). Cortisol metabolite concentrations in faeces tended to decrease during the period of lunging, were not increased when the horses were first mounted by a rider but rose slightly with an increasing work load during the last 4 weeks of the 10-week training period. In conclusion, based on HR and faecal cortisol metabolite concentrations, the initial training of sport horse stallions in the classical German training system is not associated with major stress for the horse. The increase in HR during training is due to physical exercise itself and not associated with specific situations of the training programme.
Supported by a fellowship from Stiftung Forschung für das Pferd to AS |
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Ransom, J. I., & Cade, B. S. (2008). Influences of immunocontraception on intraband social behavior in free-ranging feral horses, Equus caballus. In IESM 2008.
Abstract: Contraception is often considered for population control of wildlife that is otherwise protected from more traditional management strategies, though little is known about the behavioral consequences of contraception in wild populations of socially complex animals. Feral horses, Equus caballus, in the western United States are ideal candidates for contraceptive management due to broad scale federal protection, reported herd growth rates of 15-25% per year, and finite public land allocated for them. We investigated influences of the immunocontraceptive porcine zona pellucida (PZP) on social behavior within bands of feral horses in three discrete populations for 4 years. Each band consisted of a single stallion and a harem of adult females (>1 years old) and their foals, as well as associated yearling males and females. Four mutually exclusive behaviors (herding, reproductive, harem tending, and agonism) were analyzed to investigate the difference between behaviors initiated by band stallions toward control mares and contracepted mares within the bands. Additionally, spatial relationships between each stallion and each harem female were analyzed to assess possible passive interactions. A candidate set of 22 hierarchical mixed effects models, using the discrete populations as a random effect on various fixed effects, was analyzed by restricted maximum likelihood estimation. The most supported models were selected by corrected Akaike"s Information Criteria (AICc). Analyses were done on 3 female age cohorts based on distinct fecundity rates: 2 to 5 year olds, 6 to 14 year olds, and > 14 year olds. Stallions herded control mares in the 6 to 14 year cohort more than contracepted mares (n=128, P=0.037) with treatment being the most supported effect, but foal presence (dependent foal) also contributed significantly to the model. Contracepted mares received more reproductive behaviors than control mares in the 6 to 14 year cohort (n = 151, P=0.020). No differences were detected in herding or reproductive behaviors in
the least fecund groups, the 2 to 5 year olds and ≥ 15 year olds. The only independent variable in the most supported model for reproductive behavior was treatment, and the covariates of foal presence, band residence (resident or transient female), band size, and body condition did not contribute. There were no differences in any age cohort for harem tending or agonism. Spatially, stallions maintained closer relationships with 2 to 5 year old contracepted females than with the same age control females (n=136, P < 0.001) while the group was feeding (at its most dispersed structure), but there were no differences while the band was resting or in locomotion. There were no spatial differences detected in the other age cohorts. Given the polyestrous nature and high fecundity of feral horses, the observed difference in reproductive behaviors between treatment groups was not surprising; however, the difference detected in herding rates was an unexpected behavioral modification. This change in herding behavior suggests that further investigation is needed to determine if PZP immunocontraception has an underlying influence on mare social rank, band structure, and band stability, as well as the scope and long-term importance of these behavioral dynamics. |
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Proops, L., McComb, K., & Reby, D. (2008). Cross-modal individual vocal recognition in the domestic horse. In IESM 2008.
Abstract: Horses fulfill many of the criteria for a species in which it would be adaptive to be capable of individual recognition: they are highly social, form strong and long lasting bonds, their affiliations are rarely kin based, they have a fission-fusion social structure and they possess inter and intra-group dominance hierarchies.
We used a novel cross-modal, expectancy violation paradigm to provide the first systematic evidence that a non-human animal – the domestic horse- is capable of cross modal recognition. We believe this paradigm could provide an ideal way to study individual recognition across a wide range of species. For full published details see: Proops L, McComb K, Reby D (2009) Cross-modal individual recognition in domestic horses (Equus caballus). Proc Natl Acad Sci U S A 106: 947-951. |
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Proops, L., McComb, K., & Reby, D. (2008). Horse-human interactions: Attention attribution and the use of human cues by domestic horses (Equus caballus). In IESM 2008.
Abstract: Recent research has shown that domestic dogs are particularly good at reading human attentional cues, often outperforming chimpanzees and hand reared wolves [1, 2]. It has been suggested that the close evolutionary relationship between humans and dogs has led to the development of this ability, however very few other species have been studied [3]. We tested the ability of 24 domestic horses to discriminate between an attentive and inattentive person when choosing whom to approach for food. While the attentive person faced forwards, the inattentive person either stood with their body turned 180° away from the subject (body orientation condition), stood with their body facing forwards but their head facing away (head orientation condition) or stood facing forwards but with their eyes closed (eyes closed condition). A fourth, mixed condition was included where the attentive person stood with their body facing away from the subjects but their head turned towards the subject while the inattentive person stood with their body facing the subject but their head turned away. Horses chose the attentive person significantly more often using the body cue (n = 24, k = 19, p = 0.003), the head cue (n = 24, k = 18, p = 0.011), and the eye cue (n = 24, k = 19, p = 0.003) but not the mixed cue (n = 24, k = 13, p = 0.42). In an additional pilot study, horses were tested in an object choice task. A human experimenter cued one of two buckets by either tapping the bucket (tap condition), orienting their body towards the bucket and pointing (body and point condition), pointing while facing forwards (point condition) or orienting their body towards the bucket (body condition). If the subjects chose the correct bucket they were rewarded. Subjects were able to use the tap cue (n = 31, k = 21, p = 0.035), body + point cue (n= 31, k = 21, p = 0.035) and the point cue (n = 30, k = 21, p = 0.021) but not the body cue (n = 31, k = 11, p = 0.076). These results taken together suggest that domestic horses are also very sensitive to human attentional cues, including gaze.
Keywords: social cognition, animal-human interaction, horses, attention attribution, domestication 1. Hare, B., Brown, M., Williamson, C., and Tomasello, M. (2002). The domestication of social cognition in dogs. Science 298, 1634-1636. 2. Gacsi, M., Miklosi, A., Varga, O., Topal, J., and Csanyi, V. (2004). Are readers of our face readers of our minds` Dogs (Canis familiaris) show situation-dependent recognition of human’s attention. Animal Cognition 7, 144-153. 3. Hare, B., and Tomasello, M. (2005). Human-like social skills in dogs? Trends Cogn. Sci. 9, 439-444. Keywords: social cognition; animal-human interaction; horses; attention
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Nagy, K., Bodó, G., Bárdos, G., & Harnos, A. (2008). Is modified Forssell"s operation superior to cribbing collar in preventing crib-biting in horses? In IESM 2008.
Abstract: Crib-biting (wind-sucking) might be a coping response of the horses to the challenges of
uncontrolled environmental events. Prevention of this stereotypic behaviour evokes physiological responses consistent with increased stress. Reducing the incidence of cribbiting, however, is important in order to prevent undesirable physical and behavioural consequences (tooth erosion, altered gut function, gastric inflammation/ulceration, colic, etc.). Common treatment of crib-biting is the application of a cribbing collar, which limits the flexion of the neck making this stereotypic movement uncomfortable and difficult. Another method, the modified Forssell"s operation, is becoming more and more popular amongst the horse owners. It is based on the removal of the muscles used in crib-biting (m.omohyoideus, m.sternohyoideus, m.sternothyrohyoideus) and the ventral branches of the spinal accessory nerves. Surveys on the success of this surgical procedure have revealed inconsistent results, and, contrary to the cribbing collar, its effect on the stress level have not been studied either. The aim of our study was to determine whether the modified Forssell"s procedure is superior to the cribbing collar treatment. Differences in stress management was tested by a crib-biting provoking test, in which surgically treated horses, crib-biting horses, crib-biting horses with cribbing collar, and normal horses (those showing no stereotypies), altogether 56 horses were compared. In this test, a food bucket had been placed out of the reach of the animal, from which titbits were given 3 times. Behaviour and heart rate variability (HRV) of the horses were recorded and analysed throughout the test. Hypotheses were tested by linear mixed model. According to our results, both prevention methods (collar or surgery) inhibited crib-biting successfully though not totally. Regarding behaviour and heart rate variability, horses prevented from crib-biting (by collar or surgery) differed significantly from crib-biting and normal horses but not from each other. Normal horses were usually trying to reach the food-bucket while present and were standing still afterwards, whereas the other three groups had not really made efforts to reach the bucket, spent less time with resting, and performed or tried crib-biting. During the stress-test, normal and crib-biting horses had shown good stress-adaptation to the challenge since their HRV, after an initial increase, returned to the basal value by the end. On the contrary, HRV of the two prevented groups remained elevated and showed large oscillations throughout. They had not found a successful coping behaviour either. Our results suggest that since prevention may significantly increase distress, the treatment in itself, without changing the motivation of the horse to perform the replacement behaviour – it seems to be unsatisfactory and insufficient. After prevention the motivation of the horse to perform crib-biting should be addressed. In addition, considering that prevention by collar and surgery had not resulted in any significant behavioural or physiological differences, the superiority of the modified Forssell"s procedure might be questioned. However, the surgery might be recommended if treatment with collar is ineffective. |