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Pacheco, M. A., & Herrera, E. A. (1977). Social Structure of Feral Horses in the Llanos of Venezuela. J Mammal, 78(1), 15–22.
Abstract: Feral horses (Equus caballus) in the Venezuelan savannas (Ilanos) formed bands of 3-35 individuals; mean group size varied between 15 and 21. Some bands had up to three adult males, and there was a positive correlation between the number of males and the number of females in bands. Adult males also were seen solitary or formed bachelor groups. One association of three females was observed for 3 months. We noted a correlation between number of females in bands and number of foals per female born during our study (January-July 1992). The advantages of being in larger groups were unclear, because natural predators were rare. Perhaps females in larger groups have more time available for foraging due to reduced individual vigilance or that larger groups live in better-quality home ranges.
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Owaga Ml,. (1977). Comparison of analysis of stomach contents and feacal samples from zebra. E Afr Wildl J, 15, 217–222.
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Olsen Fw, H. R. (1977). Food relations of wild free – roaming horses to livestock and big game, Red Desert, Wyoming. J Range Mgmt, 30, 17–20.
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Nitschelm D, H. V. D. C. (1977). The influence of chlormadinone acetate treatment on the concentration of some stereoids in the blood, on the ovarian activity and on.. Tijdschr Diergeneesk, 102, 861–872.
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Nitschelm D, H. V. D. C. (1977). The influence of chlormadinone acetate treatment on the concentration of some stereoids in the blood, on the ovarian activity, and on the sexual behaviour of the.. Tijdschr Diergeneesk, 102, 61–872.
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Monfort, A., & Monfort, N. (1977). Observation of a melanistic zebra (Equus burchelli) in the Akagera. E. Afr. Wildl, 15, 173.
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Levy, J. (1977). The mammalian brain and the adaptive advantage of cerebral asymmetry. Ann N Y Acad Sci, 299, 264–272.
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Kratzer, D. D., Netherland, W. M., Pulse, R. E., & Baker, J. P. (1977). Maze Learning in Quarter Horses. J. Anim Sci., 45(4), 896–902.
Abstract: A two-compartment maze providing a single left- or right-side choice was used to test maze-learning ability in 37 quarter horses. Preference for left- or right-side choices varied among the horses. The taller and thinner horses tended to go left. The horses showed learning ability based on decreases in latency and decreases in errors as trials progressed in a right-side escape pattern. The rate of learning an opposite escape pattern, left-side escape, was faster but owing to the large number of errors occurring when the pattern was reversed, the level of errors did not reduce to a level comparable to that achieved in the right-side escape pattern until adverse stimuli were presented in the blind compartment. Heavier horses took longer to escape from the maze when adverse stimuli were presented. Differences in learning ability for horses fed various levels of dietary protein were not consistent. N1 -
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Knill, L. M., Eagleton, R. D., & Harver, E. (1977). Physical optics of the equine eye. Am J Vet Res, 38(6), 735–737.
Abstract: The equine eye was treated as a general lens system and calculations were done to determine image position in relation to the retina for objects at a distance of infinity, 100 m, and 1 m. The retina is 19.1 mm behind the posterior surface of the lens; therefore, the image appears 14.6 mm posterior to the retina at infinity and at 100 m, and 16.3 mm at 1-m distance on a horizontal axis. The animals studied were hyperopic. It is evident that the horse must move its head or eye, or both, for optimal visual acuity. At the same time, some objects in the total field of vision are imperceptible or indistinct.
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Klingel H,. (1977). Communication in Perissodactyla. (pp. 715–727,).
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