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Schusdziarra, H., Schusdziarra, V. (1986). Reitergespräche – Der Weg zum unabhängigen Sitz.
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Biederman, G. B., Robertson, H. A., & Vanayan, M. (1986). Observational learning of two visual discriminations by pigeons: a within-subjects design. J Exp Anal Behav, 46(1), 45–49.
Abstract: Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure.
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McNaughton, S. J., & Georgiadis, N. J. (1986). Ecology of African Grazing and Browsing Mammals. Annual Review of Ecology and Systematics, 17, 39–66.
Abstract: INTRODUCTION Africa is the earth's second largest continent, comprising 20% of its surface. Largely tropical, Africa extends as well into temperate zones to 37 N and 35 S. Eastern and southern Africa display steep elevation gradients due to the prevalence there of volcanic orogeny and rifting (29). Local landscapes are distinguished by substantial geological heterogeneity, dissected land forms, and resultant steep gradients of precipitation and vegetation. The consequent pronounced fragnientation of habitats and sharp juxtaposition of distinct vegetation types, combined with climatic oscillations in geological time, contributed to major adaptive radiations of the mammalian fauna (102, 120). Early zoological expeditions recorded that habitat fragmentation and wide spatial variation of animal densities and diversities were distinctive features of African ecosystems (92, 138, 162, 226). Those early records provided the bases of natural history information on animal distributions, habitat preferences, feeding habits, and general ecology; scientific research followed only much later (201). Modem scientific study of African savanna-grassland mammals began in the 1950s (23, 24, 107, 108, 148, 149, 197,203, 204, 210,230), long after the distributions and densities of the major game animals had been affected by growing human populations, colonial land and hunting policies, and virulent exotic diseases that affected the animals both directly and indirectly (57). The mammalian fauna has been increasingly isolated and fragmented within game reserves of varying size, habitat diversity, and animal species diversity; the ability to sustain it in the absence of active management is increasingly questioned (112, 187). For species with population sizes greater than 100 individuals, game reserve area (A) and faunal ...
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YALDEN DW et al,. (1986). Catalogue of the mammals of Ethiopia 6; II. order Perissodactyla; A. Family Equidae Monitore Zool italiano Suppl, 21, 35–41.
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Cunningham, C., & Berger, J. (1986). Wild horses of the Granite Range. Natural History, , 32–39.
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Heird, J. C., Whitaker, D. D., Bell, R. W., Ramsey, C. B., & Lokey, C. E. (1986). The effects of handling at different ages on the subsequent learning ability of 2-year-old horses. Appl. Anim. Behav. Sci., 15(1), 15–25.
Abstract: Forty weanling Quarter Horses, from the Pitchfork Ranch, Dickens, Texas, were randomly assigned to one of five groups based on the amount of handling they would receive. The five groups were: (1) limited handling; (2) 1 week of handling; (3) 2 weeks of handling; (4) 3 weeks of handling; (5) continuous handling for 18 months. As 2-year-olds, the horses were tested in a simple place-learning T-maze after being preconditioned. A maximum of 30 daily trials were conducted for 20 consecutive days, with feed location alternating between sides on successive days. If a horse met the criterion of 11 out of 12 correct responses with 8 correct responses being consecutive, it was retired without completing the 30 trials. Group 1 made fewer correct responses during the 20 days than any other group except Group 3. All groups achieved learning by Day 10, but the most-handled group reached a consistently higher percentage of correct responses earlier than the less-handled groups. Group 5, the group receiving the most handling, was the least emotional, as determined by the animals' reactivity to a novel stimulus, and received the highest scores for trainability after being ridden. Preconditioning trainability scores, or estimates of the horses' ability to learn prior to conditioning and testing, tended to predict maze-learning ability. These scores were also significantly correlated with post-maze training scores.
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Liang, K. - Y., & Zeger, S. L. (1986). Longitudinal data analysis using generalized linear models. Biometrika, 73(1), 13–22.
Abstract: This paper proposes an extension of generalized linear models to the analysis of longitudinal data. We introduce a class of estimating equations that give consistent estimates of the regression parameters and of their variance under mild assumptions about the time dependence. The estimating equations are derived without specifying the joint distribution of a subject's observations yet they reduce to the score equations for niultivariate Gaussian outcomes. Asymptotic theory is presented for the general class of estimators. Specific cases in which we assume independence, m-dependence and exchangeable correlation structures from each subject are discussed. Efficiency of the pioposecl estimators in two simple situations is considered. The approach is closely related to quasi-likelihood.
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Groves Cp,. (1986). The taxonomy, distrubution, and adaptations of recent equids. Tübinger Atlas Vorderer Orient Beihefte Reihe A 19, , 11–65.
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Rau Re,. (1986). The quagga and its kin. Sagittarius 1, , 8–10.
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Baker, A. E. M., & Crawford, B. H. (1986). Observational learning in horses. Appl. Anim. Behav. Sci., 15(1), 7–13.
Abstract: This experiment was designed to determine if a horse could learn the location of grain by watching another horse find grain in one of two feed buckets. Both experimental and control groups contained 9 quarter horses consisting of five 2-year-old mares, two 2-year-old geldings, and two 3-year-old geldings. Two mature geldings were used as “demonstrators”. An “experimental” was a horse that could watch three times daily another horse, the “demonstrator”, choose between and eat grain from a black or white bucket, only one of which contained grain. A “control” was a horse that could watch a demonstrator in the same arena for 3 min daily when both feed buckets were removed. When the demonstrator was removed on each of 15 successive days, the experimental or control horse was given five trials to determine if it could find the feed bucket with grain. No significant difference between experimentals and controls occurred for both first and total correct choices and for time to reach the feed bucket with grain. We conclude that no observational learning occurred. This experiment was also used to determine if the identity of horses that learned rapidly by trial and error could be predicted by the time it took to reach the feed bucket with grain. Data from the last three trials of experimentals and controls were combined. Significantly less time to find feed was needed by horses with more than the median number of correct choices. Both number of correct choices and time needed to contact a feed bucket summed over the first 5 days accurately predicted the same data summed over the last 10 days. We conclude that horses that learn rapidly by trial and error make correct choices rapidly, and that these horses can by identified after 5 days of testing.
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