Annual and seasonal rainfall may influence progeny sex ratio in the black rhinoceros
Annual and seasonal rainfall may influence progeny sex ratio in the black rhinoceros
复制标题
DOI：
10.3957/056.040.0102
复制
发表时间：
2010-04-01
影响因子：
--
通讯作者：
Linklater, Wayne L.
中科院分区：
文献类型：
--
作者：
Berkeley, Elizabeth V.;Linklater, Wayne L.
兼性性别分配理论预测，动物会对环境提示做出反应，从而对后代的性别产生偏见。在管理野外或圈养的小种群时，性别比例的偏差可能是一个问题。利用南非Hluhluwe-iMfolozi公园的降雨量和产犊记录，我们比较了季节降雨量和年降雨量与牛犊的产奶率和性别的关系。在1989-2004年间，159头小牛犊在出生后不久就被发现，从而可靠地将它们的受孕归因于特定的季节和年份。受孕具有很强的季节性，大多数(73.6%)发生在雨季，其余的发生在旱季。-2004年期间的总后代性比为53.1%。根据特里弗斯-威拉德假说，在雨季(57.3%的雄性)比在旱季(42.9%的雄性)怀孕的母牛更有可能与雄性小牛一起受孕。在多雨年和少雨年(52.2%的受孕发生在多雨年)，产生小牛的受孕数量相似。如果母牛在多雨的年份怀孕(60.2%的雄性)，而不是在干旱的年份(46.1%的雄性)，它们更有可能饲养雄性小牛。在经历了一系列多雨的年份后，将男性从小种群中移走可能特别重要，以促进更大的人口增长。
Facultative sex allocation theories predict that animals will bias their offspring's sex in response to environmental cues. Biased sex ratios can be a problem when managing small populations in the wild or captivity. Using rainfall and calving records from Hluhluwe-iMfolozi Park in South Africa, we compared seasonal and annual rainfall with calving rates and sex of the calves. Between 1989-2004,159 calves were sighted soon enough after birth to reliably attribute their conception to a particular season and year. Conceptions were strongly seasonal, with most (73.6%) occurring during rainy seasons and the remainder during dry seasons. Overall progeny sex ratio for the period 1989-2004 was 53.1% male. Mothers were more likely to be observed with male calves if they conceived during the wet season (57.3% male) than during the dry season (42.9% male) in accordance with the Trivers-Willard hypothesis. Similar numbers of conceptions that resulted in calves occurred during wet and dry years (52.2% of conceptions occurred during wet years). Mothers were more likely to raise male calves if they conceived during wet years (60.2% male) than during dry years (46.1% male). Removal of males from small populations might be particularly important after a sequence of wet years to facilitate greater population growth.