Abstract: Abstract: This study compares the behaviour of the mule (Equus asinus x Equus caballus) with that of its parent species to assess the effects of hybridization on cognition. Six mules, six ponies (E. caballus) and six donkeys (E. asinus) were given a two choice visual discrimination learning task. Each session consisted of 12 trials and pass level was reached when subjects chose the correct stimulus for at least 9 out of the 12 trials in three consecutive sessions. A record was made of how many pairs each subject learnt over 25 sessions. The mules" performance was significantly better than that of either of the parent species (Kruskal-Wallis: Hx = 8.11, P = 0.017). They were also the only group to learn enough pairs to be able to show a successive reduction in the number of sessions required to reach criterion level. This study provides the first empirical evidence that the improved characteristics of mules may be extended from physical attributes to cognitive function.

Abstract: Animals use communicative signals, such as gesture or gaze, to communicate to someone the intention or expression of the sender, which is called social cue. In the previous studies, it was suggested the skill of reading human social cue in domestic animals are influenced to the domestication, the experience contacting with human and training to obey human. In this present study, we tested the skill for horses (Equus caballus) kept in year-round grazing conditions using 33 horses differed from breed and the degree of the experience with human by object-choice task subjects choosing either of bait boxes located at the end of experimenter. As results, non-socialized horses hardly responded to human social cues. Habituated horses that were both of trained and untrained responded to human social cues, but their accuracy rates were not more than 50% except for two trained subjects. For the skill of reading human social cues, there was high individual variation in responding to human social cues in horses kept in year-round grazing conditions. The individual characteristics influenced to it more than domestication, the experience with human, and training to obey human.

Abstract: Pair and social bonding has been documented in various taxa, where pair formations are often described as being driven by kinship or sexual motivation. However, pair-bonding between unrelated individuals where sexual motivation is not a factor is not well documented. Many social relationships and pair-bonds between members of a dyad are facilitated by each individual's ability to recognise their partner using cues which are characteristic of that particular individual. The aims of this study were i) to investigate the existence of pair-bonding in domestic donkeys and ii) to determine whether members of a dyad could recognise their companion during a Y-maze recognition test. Subjects were 55 unrelated donkeys (38 gelded males, 15 females) in seven groups of mixed or same sex, comprising 4?14 individuals. Spatial proximity (nearest-neighbour) was observed three times a day over a 22-day period. Using a simulation approach based on observed data to generate randomised nearest-neighbour matrices, the statistical significance of social relationships was estimated. Of these, 42 (79.2%) were involved in significantly (p<0.05) non-random nearest-neighbour relationships, most of which were reciprocal pair relationships. Based on the spatial data, 24 of the donkeys which had shown significant reciprocal nearest-neighbour preferences for one individual (companion) were then used in a Y-maze recognition test in which they were presented with a choice of their companion and either a familiar donkey from the same group or an unfamiliar donkey from a different group. Donkeys? spatial location in the Y-maze demonstrated a preference for their companion versus familiar (one sample Wilcoxon signed rank test, W=239, p=0.002) or unfamiliar donkeys (W=222, p=0.041). These results verify anecdotal evidence from donkey handlers that donkeys often form pair-bonds, and show that reciprocal social preference and recognition are the basis of these. Pair-bond formation and companionship among donkeys have potential implications for their management, husbandry and welfare.

Abstract: This paper describes a method in which horses learn to communicate by touching different neutral visual symbols, in order to tell the handler whether they want to have a blanket on or not. Horses were trained for 10-15min per day, following a training program comprising ten steps in a strategic order. Reward based operant conditioning was used to teach horses to approach and touch a board, and to understand the meaning of three different symbols. Heat and cold challenges were performed to help learning and to check level of understanding. At certain stages, a learning criterion of correct responses for 8-14 successive trials had to be achieved before proceeding. After introducing the free choice situation, on average at training day 11, the horse could choose between a “no change” symbol and the symbol for either “blanket on” or “blanket off” depending on whether the horse already wore a blanket or not. A cut off point for performance or non-performance was set to day 14, and 23/23 horses successfully learned the task within this limit. Horses of warm-blood type needed fewer training days to reach criterion than cold-bloods (P<0.05). Horses were then tested under differing weather conditions. Results show that choices made, i.e. the symbol touched, was not random but dependent on weather. Horses chose to stay without a blanket in nice weather, and they chose to have a blanket on when the weather was wet, windy and cold (χ2=36.67, P<0.005). This indicates that horses both had an understanding of the consequence of their choice on own thermal comfort, and that they successfully had learned to communicate their preference by using the symbols. The method represents a novel tool for studying preferences in horses.