Abstract: After describing horse-riding as a facility in managing mentally ill patients, a program for chronic schizophrenic in-patients is presented. Clinical experience with this program and also results of a controlled study are reported. The therapeutic value and slope for horse-riding are discussed in relation to different diagnoses.

Abstract: Using horses, we investigated three aspects of the stimulus control of lever-pressing behavior: stimulus generalization, discrimination learning, and peak shift. Nine solid black circles, ranging in size from 0.5 in. to 4.5 in. (1.3 cm to 11.4 cm) served as stimuli. Each horse was shaped, using successive approximations, to press a rat lever with its lip in the presence of a positive stimulus, the 2.5-in. (6.4-cm) circle. Shaping proceeded quickly and was comparable to that of other laboratory organisms. After responding was maintained on a variable-interval 30-s schedule, stimulus generalization gradients were collected from 2 horses prior to discrimination training. During discrimination training, grain followed lever presses in the presence of a positive stimulus (a 2.5-in circle) and never followed lever presses in the presence of a negative stimulus (a 1.5-in. [3.8-cm] circle). Three horses met a criterion of zero responses to the negative stimulus in fewer than 15 sessions. Horses given stimulus generalization testing prior to discrimination training produced symmetrical gradients; horses given discrimination training prior to generalization testing produced asymmetrical gradients. The peak of these gradients shifted away from the negative stimulus. These results are consistent with discrimination, stimulus generalization, and peak-shift phenomena observed in other organisms.

Abstract: Faecal samples were collected at weekly intervals from pregnant Lipizzan mares during Weeks 7-16 following mating and from Lipizzan, Trotter and Thoroughbred mares during the last 3 months of gestation. After parturition, samples were taken daily from the Thoroughbred mares for another 6 days. Non-pregnant mares served as controls. The concentrations of unconjugated oestrogens (Eg), 20 alpha-OH-progestagens (20 alpha-G) and 20 beta-OH-progestagens (20 beta-G) were measured by enzyme immunoassay. In the faeces of Lipizzan mares, immunoreactive progestagens were significantly (P less than 0.01) elevated above the levels in non-pregnant mares by Week 11, and Eg by Week 13 of pregnancy onwards. During the last 3 months of gestation, concentrations of Eg were significantly higher in Trotter mares than in Lipizzan and Thoroughbred mares. Concentrations of 20 alpha-G and 20 beta-G increased to maximal values in the last month of gestation. There was no significant difference among the 3 breeds with respect to 20 alpha-G but, during the 10 weeks before parturition, concentrations of 20 beta-G in the Lipizzan mares were significantly lower (P less than 0.05) than those in the Thoroughbred mares. They were also significantly lower than those of the Trotter mares during the last 4 weeks of gestation. After parturition, the concentrations of Eg and progestagens had declined to baseline values by Days 3 and 4 respectively. From these results we conclude that high concentrations of progestagens with 20 alpha- and 20 beta-hydroxyl groups are present in the faeces of pregnant mares, especially during the last month of gestation.

Abstract: Field observations of 400 totally unmanaged feral horses on Sable Island, Nova Scotia, were complemented by oestrogen determinations in faecal samples from 154 identified females over a 4-year period (454 mare-years). Of mares that were sampled throughout the year and subsequently produced foals, 92.1% exhibited elevated faecal oestrogens between 15 October and 30 March. The results confirm that faecal oestrogens are a useful indicator of pregnancy after approximately 120 days gestation. Distribution of foaling resembled that seen in other feral populations, with 95% of births occurring from April through July. The foaling rate for mares aged 3 years or older was 62.0%, with 50.7% of mares foaling in 3 or 4 years. Foaling rates were low (4.1%) in mares bred as yearlings and rose with age to 70.8% in those bred as 4-year-olds. Fetal loss after Day 120 was deduced from faecal oestrogens to be 26.0% overall, with marked variation from year to year (9.6-37.3%) and with age (70.0% in those bred as yearlings, decreasing to 5.6% in those bred as 4-year-olds). Of 58 mares aged 2 years or older that were sampled every year, about half (49.6%) the barren years were attributable to fetal loss after 120 days gestation. All mares conceived in at least 2 of the 4 years, suggesting that pregnancy loss, even after Day 120, is as important as failure to conceive in causing barren years.

Abstract: Alliances among kin play a major role in a female's acquisition of her mother's dominance rank in many species of cercopithecines. It is noteworthy, however, that kin rarely form coalitions to challenge females from higher-ranking matrilines, and that matrilineal hierarchies are remarkably stable. One possible reason for the rarity of destabilizing coalitions is that members of high-ranking matrilines form alliances against lower ranking ones. In this paper the patterning of aggressive support among non-kin, and its effect on the stability of rank relations are analysed in a captive group of Japanese macaques, Macaca fuscata, composed of three unrelated matrilines. Analysis of the distribution of non-kin interventions in conflicts between matrilines over a 52-month period revealed a clear pattern of preferential support between the two dominant matrilines against the third-ranking one. This pattern was confirmed experimentally. Any member of the two dominant matrilines was unable, individually, to maintain its rank above the third-ranking matriline, but was able to do so in the presence of the other dominant matriline. Non-kin alliances appear to prevent subordinate females from challenging higher ranking females through revolutionary coalitions (formed among subordinates) or through bridging coalitions (formed among individuals ranking above and below the target). Non-kin support is interpreted in terms of cooperation versus reciprocal altruism.