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 &#8805; 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.

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.

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.

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

Abstract: The International Society for Equitation Science is a not-for-profit International scientific organisation with the primary function of facilitating research into the training and welfare of horses. The mission of the ISES is to promote and encourage the application of objective research and advanced practice which will ultimately improve the welfare of horses in their associations with humans. ISES provides an international forum in which scientists can communicate their most recent findings by organising annual scientific meetings and by encouraging scientific publications. Furthermore, the Society offers a pool of expertise to national governments, international bodies, industry and equine welfare organisations. The idea of founding a Society devoted to equitation science had first been raised during discussions following the Havemeyer Foundation Workshop on Horse Behaviour and Welfare in Iceland in 2002. Since then, equitation science has developed rapidly. The discipline combines learning theory, psychology, ecology, biology and ethology in order to objectively examine the efficiency of different equine training methods. The society is open for people with scientific, scholarly or professional qualifications: equine scientists, ethologists, veterinarians, behaviour therapists or qualified trainers and riders. ISES membership gives the opportunity of joining a network of internationally renowned equine scientists and advanced practitioners. Members save on registration fees for international conferences and stay informed about research and its application in practice through two newsletters per year. For further information and membership issues please visit www.equitationscience.com. During the presentation an overview will be given about the history and goals of ISES, the meetings since 2001, the current organisation- and membership structure and the future plans. Also a summary of the presentations given at the 4th International Equitation Science Conference August 2-4, 2008 in Dublin will be presented.