Modification of sperm quality after sexual abstinence in Seba's short-tailed bat, Carollia perspicillata.

In polygynous mating systems, few males have stable access to sexual mates. With an expected higher copulation rate, harem males may deplete seminal fluids or increase epididymal sperm maturation, generating poor sperm quality. In a first study, we reported a higher sperm quality in sneaker males of Carollia perspicillata. To test whether the lower sperm quality observed in harem males was generated by an elevated copulation rate, we temporarily removed males of both social statuses from the colony. We thus assessed status-related changes of sperm quality resulting from sexual abstinence. Moreover, released from territory and female guarding, harem males were expected to show a reduction in somatic costs. On the basis of sperm competition models, we predicted a higher resource investment in the ejaculate with the reduction of pre-copulatory efforts. In line with our predictions, sperm quality of harem males improved significantly in contrast to sneaker males, whose sperm quality did not...在一雄多雌交配系统（polygynous mating systems）中，仅有少数雄性能够稳定获得交配配偶。由于预期交配频率更高，后宫雄性（harem males）可能会耗尽精液储备，或加速附睾精子成熟过程，进而导致精子质量下降。在我们此前开展的第一项研究中，我们曾报道佩氏短尾叶鼻蝠（Carollia perspicillata）的偷配雄性（sneaker males）具有更高的精子质量。为验证后宫雄性所观测到的较低精子质量是否由较高的交配频率所引发，我们将两种社会地位的雄性个体暂时移出了其栖息种群，借此评估了不同社会地位雄性在禁欲后精子质量的变化差异。此外，脱离领地守卫与雌性守卫职责的后宫雄性，其躯体维持成本预计会有所降低。基于精子竞争模型（sperm competition models），我们预测，随着交配前繁殖投入的减少，雄性会将更多资源投入到射精产物中。与我们的预测相符，后宫雄性的精子质量得到了显著提升，而偷配雄性的精子质量则未出现明显变化……