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Ristau, C. A. (1983). Language, cognition, and awareness in animals? Ann. N.Y. Acad. Sci., 406(1), 170–186.
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Wimmer H, & Perner J. (1983). Beliefs about beliefs: representation and constraining function of wrong beliefs in young children's understanding of deception. Cognition, 13, 103.
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Premack, D. (1983). Animal Cognition. Annual Review of Psychology, 34(1), 351–362.
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Langlois, B., Minkema, D., & Bruns, E. (1983). Genetic problems in horse breeding. Livestock Production Science, 10(1), 69–81.
Abstract: The purpose of this paper is to give a short survey of the present problems concerning the genetic improvement of horse breeds. The evolution of these populations in Europe, characterized by a deep change from production of draught horses towards that of leisure horses, is described and the influence of the demographical parameters on the selection of these horse populations, is discussed. The generation interval represents an important handicap only surmounted in the case of racing breeds where a high selection intensity can be practised since all animals are subjected to performance testing. In the other cases, the farmer usually does not use modern breeding techniques, but uses crosses instead, which lead more easily to visible results. The available selection criteria are also dealt with. A distinction is made between direct estimates evaluating the abilities of the animals in practice and the indirect estimates measuring a character in correlation to previous ones. For the former estimates, a distinction is made between those resulting from competitions (handicap, records or earnings) and those resulting from direct in-station measurements (saddle, jumping, dressage abilities, draught power). For the indirect estimates, often used especially for the selection of mares, the most important analysis is obviously that of the conformation. However, in the future early selection criteria according to more physiological data should be sought and developed. Estimation of the breeding value according to a given ability is thereafter pointed out. There are two situations: “the panmictic case” concerning sport and draught horses and “the non-panmictic case” corresponding to racing horses, which give rise to some problems. The setting up of breeding plans is discussed. Due to the different economic situations and various objectives of horse production, conclusions are drawn about the role played by geneticists in the present development of this sector.
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Baer, K. L., Potter, G. D., Friend, T. H., & Beaver, B. V. (1983). Observation effects on learning in horses. Appl. Animal. Ethol., 11(2), 123–129.
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.
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Hinde, R. A. (1983). A conceptural framework. In R. A. Hinde (Ed.), Primate Social Relationships (pp. 1–7). Massechusetts: Sinauer, Sunderland.
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Boyd, R., & Silk, J. B. (1983). A method for assigning cardinal dominance ranks. Anim. Behav., 31(1), 45–58.
Abstract: Dominance hierarchies are widely described in nature. Commonly, an individual's ordinal rank is used as a measure of its position in the hierarchy, and, therefore its priority of access to resources. This use of ordinal ranks has several related drawbacks: (1) it is difficult to assess the magnitude or the significance of the difference in degree of dominance between two individuals; (2) it is difficult to evaluate the significance of differences between dominance matrices based on different behaviours or on the same behaviour at different times, and (3) it is difficult to use parametric statistical techniques to relate dominance rank to other quantities of interest. In this paper we describe a method for assigning cardinal dominance indices that does not suffer from these drawbacks. This technique is based on the Bradley-Terry model from the method of paired comparisons. We show how this model can be reinterpreted in terms of dominance interactions. and we describe a simple iterative technique for computing cardinal ranks. We then describe how to evaluate (1) whether the rank differences between individuals are significant, and (2) whether differences in the cardinal hierarchies based on different behaviours or the same behaviour at different times are significant. We then show how to generalize the method to deal with behaviours that sometimes have ambiguous outcomes, or behaviours for which the rank difference between a pair of individuals affects the rate of interaction between them.
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Kirkpatrick, J. F., & Turner, J. W. (1983). Seasonal ovarian function in feral mares: seasonal patterns of LH, progestins and estrogens in feral mares. J. Equine Vet. Sci., 3(4), 113–118.
Abstract: Blood was collected every 3 days for 13 months from 4 captured [female][female] of proven fertility kept adjacent to a teaser stallion. Basal plasma LH level was greater during Apr.-July (8.1+or-0.5 ng/ml) than during Nov.-Jan. (2.2+or-0.2). A total for 21 LH peaks occurred between 13 Apr. and 31 Aug. among the 4 [female][female]; many peaks exceeded 20 times the basal level, and there was a trend to a higher LH level with each succeeding peak. On all occasions except one, LH peaks were associated with progesterone levels of 0.5 ng/ml and with increases of oestrogen (peak average 43.1+or-12.1 pg/ml). Basal progesterone level during Apr.-July (1.5+or-1.2 ng/ml) did not differ significantly from that during Oct.-Jan. (1.1+or-0.7), nor did basal oestrogen level differ significantly between those 2 periods (8.4+or-3.2 and 12.9+or-4.6 pg/ml resp.). Behavioural oestrus always occurred with LH and oestrogen peaks during Apr.-July. However, behavioural oestrus was occasionally observed during Aug.-Oct., when LH peaks no longer occurred.
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Carson, K., & Wood-Gush, D. G. M. (1983). Equine behaviour: II. A review of the literature on feeding, eliminative and resting behaviour. Appl. Animal. Ethol., 10(3), 179–190.
Abstract: The literature on the feeding, eliminative and resting behaviour of horses has been reviewed to collate the information available on these subjects. The grazing and eliminative behaviour patterns of domestic horses are unlike those of free-ranging Equidae. The reasons for this are not known, but it can cause wasted grazing of up to 90% of a field. Certain conditions, such as provision of supplementary hay and lack of available herbage, can cause these behaviour patterns to change, although it is not known how to manipulate the grazing behaviour of horses to prevent deterioration of the pasture. Grazing behaviour is influenced by many variables and is more complex than the feeding behaviour of a stabled horse. Horses sleep for approximately 12% of the day and show 4 different sleep/wakefulness states -- alert wakefulness, drowsiness, slow-wave sleep and paradoxical sleep. Horses are able to maintain slow-wave sleep while standing, but they need to lie down for paradoxical sleep to occur, rarely spending more than 30 consecutive minutes in lateral recumbency.
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Carson, K., & Wood-Gush, D. G. M. (1983). Equine behaviour: I. A review of the literature on social and dam--Foal behaviour. Appl. Animal. Ethol., 10(3), 165–178.
Abstract: In most cases, the social organisation of each of the seven species of Equidae existing today outside captivity is either territorial or non-territorial. The striking differences found between these two types of organisation in the social grouping and bonds, mating behaviour, leadership and dominance hierarchies of the animals are examined. It is thought that the non-territorial species show a less primitive type of organisation than the territorial animals. Infant Equidae are precocious animals and are able to follow their dams soon after birth. They stay close by their dams and travel with the herd from an early age and are therefore classified as “followers”, in contrast to the species which have a period of hiding after birth. Dams recognise their foals immediately after birth, whereas it takes 2 or 3 days for a foal to form an attachment to its dam. Being in close proximity to their dams, foals are able to nurse frequently and, unless artificially weaned, a foal will nurse until its dam foals again. Foals start to graze during their first week and as they grow older they spend more time grazing and less time nursing and resting. It is normal for foals to be corprophagic until one month old, and this provides them with bacteria essential for the digestion of fibre. Play behaviour is solitary in very young foals, but after 4 weeks of age, foals play together, with male foals playing more than females and showing more aggressive, fighting movements in play.
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