Abstract: Self-grooming behaviour of 15 mare-foal pairs was studied weekly for the first 24 weeks of the foal's life. Mares self-groomed at mean rates of 1.2-2.2 times h-1 depending on the 4-week period. Foals self-groomed more often, with a peak rate of 12.3 times h-1 occurring during Week 5-8 and a subsequent decline to 6.0 times h-1 by Weeks 21-24. Self-grooming bouts of mares and foals also differed in the proportion devoted to each type of self-grooming. During a greater proportion of their total self-grooming bouts, foals scratched their head and neck with a hind limb or bit and scratched the trunk or hind limbs with the teeth. The mares spent a greater proportion of their self-grooming bouts rubbing their head or neck on an inanimate object, another pony, or their fore limb, or rolling on the ground. Particular types of individual self-grooming bouts were engaged in for different lengths of time. Foals had longer bouts of scratching the head and neck with a hind limb, scratching or biting the fore limb or hind limb with the teeth, and rubbing the head and neck on an inanimate object, while mares had longer bouts of rolling. Some of the differences in preference for particular types of self-grooming may be the result of differences in relative size of various body parts and, consequently, relative ease of a given type of self-grooming.

Abstract: The purpose of the following study was to determine if head partitions would facilitate feeding by subordinate horses in the presence of dominant pen-mates. Six pairs of mares, each with established dominant-subordinate relationships, were allowed to compete for feed in a 112-cm trough following 24 h of deprivation. Time spent feeding by each mare in each pair was recorded with a wire-mesh partition, a solid plywood partition or no partition dividing the trough. Differences in feeding times between dominant and subordinate mares were greatest in the absence of a partition and least (P<0.05) with the wire barrier in place. Differences in feeding times with the solid plywood barrier were not significantly different from either of the other treatment conditions. It was concluded that head partitions on a trough facilitate feeding by subordinate horses in the presence of dominant pen-mates and thus provide a more equitable distribution of food resources.

Abstract: A basic principle of human memory is that lists that can be organized into memorable 'chunks' are easier to remember. Memory span is limited to a roughly constant number of chunks and is to a large extent independent of the amount of informaton contained in each chunk. Depending on the ingenuity of the code used to integrate discrete items into chunks, one can substantially increase the number of items that can be recalled correctly. Newly developed paradigms for studying memory in non-verbal organisms allow comparison of the abilities of human and non-human subjects to memorize lists. Here I present two types of evidence that pigeons 'chunk' 5-element lists whose components (colours and achromatic geometric forms) are clustered into distinct groups. Those lists were learned twice as rapidly as a homogeneous list of colours or heterogeneous lists in which the elements are not clustered. The pigeons were also tested for knowledge of the order of two elements drawn from the 5-element lists. They responded in the correct order only to those subsets that contained a chunk boundary. Thus chunking can be studied profitably in animal subjects; the cognitive processes that allow an organism to form chunks do no presuppose linguistic competence.

Abstract: Individual differences in shading behaviour within a flock of sheep could be due to differences in thermoregulatory capabilities or to the influence of social factors. The possible influence of social factors on shade-use is examined in this paper. Two measures of dominance were made on 39 Merino wethers. These were based on the hierarchy determined by butting during feeding and on priority of access to limited feed. Leadership was also assessed while driving the sheep to a woolshed and as the sheep entered weighing scales. These behavioural traits were compared with leadership to shade and shade-use observed on 9 days during summer in a small pastureless enclosure containing natural shade. Maximum ambient temperature on these 9 days varied between 29.0 and 39.5[degree sign]C. All behavioural traits examined were significantly repeatable. The two dominance ranks were negatively correlated (P<0.05). The butting hierarchy was correlated with shading behaviour; those sheep that butted the larger proportion of the flock were seen to shade for longer periods of time (P=0.05). This relationship became more significant as environmental temperature increased. Significant (P<0.05) differences in the amount of time each sheep spent shading were evident throughout the flock, but in particular seven individuals shaded much less than others. Shade-use increased in hot weather and was slightly more strongly correlated with radiation load than with air temperature. The non-shading leadership ranks were related neither to each other nor to the leadership to shade. However, the sheep that moved to shade first remained there longest (P<0.05). Reduced motivation to feed did not appear to explain early movement to shade. Few overtly aggressive or other interactions between animals were seen to be associated with movements to or within shade. Nonetheless, the results indicate that social forces do exert some influence on shade-use.

Abstract: The structure of the play of colts and fillies living on pasture was studied from birth (n = 15) for up to 24 weeks. Foal play was categorized as running and bucking alone, running and bucking in a group, interactive (contact or combat) play, play with an object, and play at an adult. The rate of play decreased with increasing age and ambient temperature. Fillies and colts played with equal frequency, but engaged in some different types of play at different rates. There was no difference between colts and fillies in the proportion of play bouts of running and bucking in a group or playing with an object. Fillies engaged in running and bucking alone more than colts. Colts engaged in interactive play and play at an adult more than fillies. While there was no significant difference between colts and fillies in the duration of either type of running and bucking play, the interactive play bouts of colts were significantly longer than those of fillies. Both mares and stallions were tolerant of foal play which involved use of their body as a play object, including mounting play. Both fillies and colts engaged in mounting play. Foals used various natural objects found in the pasture for repeated bouts of play with inanimate objects, a behaviour which may explain, from a developmental perspective, the occasional use of “tools” in adult equids. The sex differences in type of play were consistent with the social structure of unmanaged adults in which males must compete with each other in order to associate with females.