Ginsberg, J. R., & Rubenstein, D. I. (1990). Sperm competiton and variation in zebra mating behaviour. Behav. Ecol. Sociobiol., 26(6), 427–434.
Abstract: Data are presented on the breeding behavior of two zebra species to test whether intra- and interspecific variation in male reproductive behavior and physiology are correlated with differences in female promiscuity. In one species, plains zebra (Equus burchelli) females live in closed membership single male groups and mate monandrously. In the other species, the Grevy's zebra (E. grevyi) females live in groups whose membership is much more temporary. Typically, associations with individual males are brief and mating is polyandrous. However, some females – those having just given birth – reside with one male for long periods, mating monandrously. These differences in female mating behavior generate variability in the potential for sperm competition. We show that behavioral differences in male investment in reproductive activities correlate with the potential for sperm competition. When mating with promiscuous mares, Grevy's zebra stallions made a greater investment in reproductive behavior (calling, mounting, ejaculations) than did stallions of either species when mating with monandrous females. The evolution of large testes size in the Grevy's zebra, when compared to the congeneric plains zebra, horse, and mountain zebra, allows for this increased investment.
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Keiper Rr,. (1979). Population dynamics of feral ponies. Laramie: Symposium on the Ecology and Behavior of wild and feral Equids.
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Kahurananga, J., & Silkiluwasha, F. (1997). The migration of zebra and wildebeest between Tarangire National Park and Simanjiro Plains, northern Tanzania, in 1972 and recent trends. Afr J Ecol, 35(3), 179–185.
Abstract: In 1972, four aerial censuses were carried out to assess the annual migration of zebra and wildebeest between Tarangire National Park and Simanjiro Plains. About 6000 zebra and 10,000 wildebeest were in the Plains in the middle of the rainy season, in April. During the dry season in August the animals were concentrated in the Park. The migration from the Park to the Plains started at beginning of the rains, in November/December. Recent censuses by Tanzania Wildlife Conservation Monitoring (TWCM, 1991, 1995) indicate that an estimated 23,000 zebra and 11,000 wildebeest migrate into the Park from Simanjiro and other wet season areas. Encroaching cultivation is a threat to the migration corridors and sustainability of the ecosystem . Providing benefits from wildlife to communities around the park would safeguard the future of the wildlife.
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Klingel H,. (1980). A Comparison of the Social Organization of the Equids. in Denniston RH (ed).
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Ruffner Ga, C. S. (1979). Age structure, condition, and reproduction of two burro (Equus asinus) populations from Grand Canyon National Park, Arizona.
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Waring Gh,. (1979). Behavioral adaptation as a factor in management of feral equids.
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Wolfe Ml,. (1979). Feral horse demography: A preliminary report (Abstract).
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Wolfe Ml,. (1979). Population ecology of the kulan.
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Woodward Sl,. (1979). Population dynamics of a herd of feral burros (Abstract).
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Zervanos Sm, K. R. (1979). Seasonal home ranges and activity patterns of feral assateague island ponies.
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