Abstract: Abstract  Affiliative relationships among mares were examined in a managed group of Sorraia horses, Equus caballus, over a 3-year period. We assessed the influence of age, dominance, kinship and reproductive state on the strength of affiliative relationships and diversity of partners. The herd comprised 9–11 mares that had known each other since birth, their foals and a stallion that remained in the group exclusively during the breeding season. In contrast to a previous study, kinship did not significantly affect bonds. Mares tended to spend more time in proximity to those in the same reproductive state. Affiliative relationships among mares were relatively stable but their strength decreased after foaling, possibly as a function of foal protection and bonding between dam and foal. There was no consistent evidence that mares disengaged from affiliative relationships with increasing age. As expected, dominant mares and barren mares contributed the most to affiliative relationships. Dominance rank increased with age, but dominance relationships were stable and did not change after foaling. Overall, reproductive state was the factor that had the most consistent influence on affiliative relationships among Sorraia mares.

Abstract: Sixteen horses, divided into 2 groups of 8, were used to study observational learning in horses. One group served as controls while the other group served as the treated group (observers). Observers were allowed to watch a correctly performed discrimination task for 5 days prior to testing their learning response using the same task. Discrimination testing was conducted on all horses daily for 14 days, with criterion set at 7 out of 8 responses correct with the last 5 consecutively correct. The maximum number of trials performed without reaching criterion was limited to 20 per day. Mean trials to criteria (MT) by group were: control, 11.25; observer, 10.70. Mean error (ME) scores were: control, 2.37; observer, 2.02. Average initial discrimination error scores were 11.13 for control and 10.38 for observers (P < 0.10). Asymptote was reached by Day 8 for both control and observer groups. Analysis of variance with repeated measures showed an extreme-day effect indicative of learning (P < 0.01), with non-significant differences in learning rate between experimental groups. Whether the initial ability of the horses to perform a discrimination learning task was enhanced by observation of other horses' performance of that task was not obvious from these data.

Abstract: There are numerous areas worthy of study in the field of domestic animal behavior or applied ethology. In this paper a few areas are offerred as particularly worthy of attention. These areas are worthwhile either because they have received little or no study and are of basic interest or because they have application to current problems of livestock production. The study of cat behavior falls in the former category. Neither the food and water sources, the reproductive success rate nor even the social interactions of cats in the large populations found in both rural and urban environments are known. Pigs as a species have already been the subjects of many behavior studies; nevertheless, there are still gaps in our knowledge of the underlying principles of swine behavior. The physiological basis of maternal behavior, for example, has not been studied in swine or in any domestic species. The sensory basis of udder location by the neonatal piglet deserves study also. Some aspects of olfactory and vocal communication of pigs have been studied, but only one of what may be a large number of pheromones of pigs has been chemically identified. The message conveyed by the vocal interactions between adult swine of the same sex is unknown, as is the role of facial and postural expressions in porcine communication. The two major problems of pig behavior under conditions of intensive livestock management are tail biting and reproductive failure. The application of behavioral techniques to these problems might help to attenuate those problems as well as broaden our understanding of normal pig behavior. Horse behavior has also been a relatively neglected field of study. Of particular interest is the significance of the flehmen gesture used by both mares and stallions in a variety of situations. Flehmen may be related to the function of the vomeronasal organ, but both observational and physiological studies should be performed to verify the hypothesis.

Abstract: Abstract * 1Animals can derive leverage over others from (a) resource holding power, based for instance on fighting ability or dominance, and (b) the possession of commodities, such as special skills and resources that cannot be taken away by force. * 2We contend that power based on the possession of commodities strongly depends on the level of supply and demand for that commodity, a phenomenon we call the ‘market effect’. * 3Several theoretical and empirical examples are given of social systems in which animals belong to two distinct classes that offer two different kinds of commodities. * 4The relative frequency of occurrence of the two classes is shown to determine the relative power of their members. * 5We consider the theoretical properties of bargaining processes by which relative power is converted into corresponding pay-off distributions. * 6We propose coalition games, a class of games with more than two players and in which bargaining is possible, as suitable paradigms for collaboration among members of social units.