Abstract: Three horses (Equus caballus) with a history of performing cognitive tasks including discrimination learning, categorization, and concept use were tested to evaluate their long-term memory (LTM) in three experiments. In addition, use of LCD multi-displays for stimulus presentation was incorporated into cognition testing protocol for the first time with horses. Experiment 1 tested LTM for discrimination learning that originally occurred 6 years earlier. Five sets of stimuli were used and the two horses tested showed no decrement in performance on four of the sets; however, both horses did score below chance on one set. Experiment 2 examined long-term categorization recall 10 years after horses had demonstrated the ability to make stimulus selections based on shared characteristics within a given category. The horse tested for LTM after the decade-long interval immediately and consistently applied the previously learned categorization rule to not only familiar but also novel sets of stimuli. Experiment 3 tested another horse for LTM for a relative size concept. This horse had originally demonstrated concept rule use in order to select stimuli based on their relative size to one another. More than 7 years later and without further training, this horse reliably applied the previously established size concept to both familiar and novel sets of stimuli. These findings are the first reports of long-term categorical and conceptual memory in horses and are consistent with observations of domestic and wild horses, which indicate that behavioral and ecological events may be remembered for long periods of time. These studies also demonstrate the adaptive nature of horses with regard to their ability to generalize over several different testing conditions.

Abstract: Habituation to frightening stimuli plays an important role in horse training. To investigate the extent to which horses generalise between different visual objects, 2-year-old stallions were habituated to feeding from a container placed inside a test arena and assigned as TEST (n=12) or REFERENCE horses (n=12). In Experiment 1, TEST horses were habituated to six objects (ball, barrel, board, box, cone, cylinder) presented in sequence in a balanced order. The objects were of similar size but different colour. Each object was placed 0.5m in front of the feed container, forcing the horses to pass the object to get to the food. TEST horses received as many 2min exposures to each object as required to meet a habituation criterion. We recorded behavioural reactions to the object, latency to feed, total eating time, and heart rate (HR) during all exposures. There was no significant decrease in initial responses towards a novel object with increasing object number, indicating that habituation was stimulus-specific. REFERENCE horses were exposed to the test arena without objects in the same period, and reactions of TEST and REFERENCE horses were subsequently compared in a fear-test (2m2.5m rubber mat placed under the feed container, forcing the horses to step on the mat to get food). There were no significant differences between the treatment groups, i.e. previous habituation of TEST horses to six visual objects did not reduce responses in a fear-test involving visual and tactile stimulation. Due to the lack of generalisation in Experiment 1, we designed a supplemental experiment (Experiment 2), in which REFERENCE horses were exposed to the same six objects except that object colour was kept constant. We found a significant reduction in response (behaviour and HR) with increasing object number, indicating that horses generalise between similarly coloured objects of varying shape. We conclude that a high degree of object similarity, e.g. identical colouring, appears to be crucial for object generalisation in horses.

Abstract: Since the time of domestication, humans have trained horses for the purpose of serving man. Different training methods have been developed throughout the centuries; some were developed with consideration for the horse's welfare, while others disregarded welfare to a great extent. Most present day training is based upon making the horse perform a desired behaviour through dominance and subordination. Although cooperative training techniques have gained popularity, everyday training lacks the application of learning theory or neglects the horse's learning capacities and their species' specific behaviour. Thus, the horse's welfare may be jeopardised.
The aim with this review is to consider methods that allow an objective assessment of the welfare of horses undergoing training. The review gives a brief insight into the history of horse training and handling. It proceeds with an overview of the horse"s learning abilities which is argued to be of paramount importance for effective training. The review then describes a few selected training techniques that are used today, based on negative and positive reinforcement, and discusses parameters from which it could be possible to assess the welfare of the ridden horse. The work concludes with suggestion for future

Abstract: The aim of this study was to test the existence of a “reactivity-to-humans” trait which is stable over time and across situations. For this purpose, four test situations were repeated on the same animals at 8 months, 1.5 years (N = 110 horses) and 2.5 years of age (N = 54 horses). These situations involved a “familiar passive human test” during which a familiar person stayed motionless in the test pen, a “familiar active human test” and an “unfamiliar active human test” during which a familiar or unfamiliar person attempted to touch the horse, and a “halter-fitting and heart-rate measurement test”, during which the horse was haltered and equipped with a surcingle and then had its heart-rate measured. Many behavioural variables were recorded during the tests, and correlations between ages and variables measured during other situations were investigated. When correlations were found, we concluded that the variables corresponded to temperament traits which are stable over time and across situations. The horses tested were divided into four groups according to breed (Anglo-Arab and Welsh) and year of birth (2001 and 2002). Data for each group were analysed separately with Spearman rank correlations. Regarding stability over time, there was a strong correlation between ages in the frequency of licking/nibbling the passive human, the time taken by a familiar or unfamiliar person to touch the horse, and the time taken to fit a halter (e.g. the time taken to touch the horse's muzzle was significantly correlated between ages in 7 out of the 8 possible cases: 0.40 <= R <= 0.67). Regarding stability across situations, results indicate that the more frequently a horse sniffed, licked or nibbled a passive human, the easier it was for either a familiar or unfamiliar active human to touch and halter it. Moreover, a horse which could be touched easily by a familiar human could also be touched and haltered easily by an unfamiliar human. These behaviours, which are linked directly to humans, therefore indicate good stability over time and across situations. In conclusion, this stability suggests the existence of a “reactivity-to-humans” temperament trait, whether the human is passive or active, familiar or unfamiliar. When the animals do not have frequent contact with humans, this reactivity is stable over time and can be measured as early as 8 months of age using the behavioural variables cited above.

Abstract: Przewalski horses (Equus ferus przewalskii), also known as takhi, were first re-introduced to the wild in Hustai National Park, Mongolia, in 1994. Since then the number of free harems increased to a maximum of seven; there are currently six (October 2000). The size of the home range of each of the harems changed among years and among seasons. The horses tended to settle in a home range close to where they were released although they explored the surrounding area. The use of the habitat within each home range changed through the day, with the horses grazing in the valleys during the morning and evening, and moving to higher places to stand rest and use as a refuge from heat and flies during the middle of the day. Range establishment and area, as well as habitat use are discussed.