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Hildebrand, M. (1987). The Mechanics of Horse Legs. Amer. Sci., 75(6), 594–601.
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Hughes, K. L., & Sulaiman, I. (1987). The ecology of Rhodococcus equi and physicochemical influences on growth. Vet Microbiol, 14(3), 241–250.
Abstract: Growth of Rhodococcus equi was studied in vitro. Optimal growth occurred under aerobic conditions between pH 7.0 and 8.5, at 30 degrees C. R. equi survived better in a neutral soil (pH 7.3) than it did in two acid soils (pH less than 5.5). It grew substantially better in soils enriched with faeces than in soils alone. Simple organic acids in horse dung, especially acetate and propionate, appear to be important in supporting growth of R. equi in the environment. The ecology of R. equi can be best explained by an environmental cycle allowing its proliferation in dung, influenced by management, grazing behaviour and prevailing climatic conditions. Preventive measures should be aimed at reducing or avoiding focal areas of faecal contamination in the environment.
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Hunte, W., & Horrocks, J. A. (1987). Kin and non-kin interventions in the aggressive disputes of vervet monkeys. Behav. Ecol. Sociobiol., 20, 257–263.
Abstract: Interventions in aggressive disputes were investigated in a free-living troop of vervets (Cercopithecus aethiops sabaeus) in Barbados. Interventions on behalf of kin were more frequent than on behalf of non-kin. Both types of interventions were more likely when the intervening animal outranked the opponent; presumably because retaliation probability, and hence cost of intervening, is low against low ranking opponents. The number of interventions given on behalf of both kin and non-kin increased with the number of disputes in which they were involved. In contrast to kin interventions, the number of interventions given on behalf of non-kin was correlated with that received by non-kin, suggesting that reciprocation is a necessary component of non-kin interventions. Non-kin interventions were more likely when the recipient outranked the opponent, presumably because reciprocation probability is high. Pairs of non-kin form structured reciprocal relationships based on the proportion of interventions allocated to each other, and most non-kin interventions flowed through these relationships. Males intervened on behalf of non-kin more frequently than did females. The implications of the results for the evolution of kin and reciprocal altruism were discussed.
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Huntingford, F., & Turner, A. (1987). Animal Conflict.
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Illius, A. W., & Gordon, I. J. (1987). The Allometry of Food Intake in Grazing Ruminants. T. J. Anim. Ecol., 56(3), 989–999.
Abstract: A simulation model of grazing mechanics in ruminants shows that, due to the allometric relations of bite size and metabolic requirements to body size, small animals are able to subsist on shorter swards than large animals. (2) The density of nutrients in the grazed horizon of the modelled swards markedly affected the ability of animals of a given body size to satisfy their energy requirements. (3) By extension, the allometric relationships would be expected to apply in selective grazing and browsing species in their choice of food items of different size and nutrient content. (4) The results support the argument that sexual segregation and habitat choice of dimorphic species is an effect of scramble competition for limited resources, the males thus being excluded from mutually preferred swards. (5) The model provides an explanation for two interspecific phenomena amongst grazers: grazing succession and grazing facilitation.
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Kacelnik, A. (1987). Information primacy or preference for familiar foraging techniques? A critique of Inglis & Ferguson. Anim. Behav., 35(3), 925–926.
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Klingel H,. (1987). Unpaarhufer, Pferde. in Grzimek B (ed): Grzimeks Enzyklopädie Säugetiere, 4, 548–592, Kindler.
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Lane, J. G., & Mair, T. S. (1987). Observations on headshaking in the horse. Equine Vet J, 19(4), 331–336.
Abstract: The clinical records of 100 cases of headshaking in horses were reviewed. Possible causes of the abnormal behaviour were identified in 11 animals; these included ear mite infestation, otitis interna, cranial nerve dysfunction, cervical injury, ocular disease, guttural pouch mycosis, dental periapical osteitis and suspected vasomotor rhinitis. However, in only two of these could it be shown that correction of the abnormality led to elimination of the headshaking. The additional clinical signs exhibited by the other idiopathic cases of headshaking included evidence of nasal irritation, sneezing and snorting, nasal discharge, coughing and excessive lacrimation. Many of these horses also showed a marked seasonal pattern with respect to the onset of the disease and the recurrence of signs in subsequent years. The clinical presentation of idiopathic headshakers and the seasonal incidence of the signs closely resemble allergic rhinitis in man.
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Leslie AM. (1987). Pretense and representation in infancy: the origins of theory of mind. Psychol. Rev., 94, 412.
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Lisa Nash, H., Song, G. K., & Price, E. O. (1987). Head partitions facilitate feeding by subordinate horses in the presence of dominant pen-mates. Appl. Anim. Behav. Sci., 19(1-2), 179–182.
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.
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