The hydration state of animals vying for reproductive success may have implications for the tempo and mode of sexual selection, which may be salient in populations that experience increasing environmental fluctuations in water availability. Using red-sided garter snakes as a model system, we tested the effect of water supplementation on courtship, mating behavior, and copulatory plug (CP) production during a drought year. Over 3 days of mating trials, water-supplemented males (WET males, n = 45) outperformed a control group that was not supplemented with water (DRY males, n = 45). Over 70% of WET males mated but just 33% of DRY males did so. As a group, WET males mated 79 times versus 28 times by DRY males. On the last day of mating trials, over 70% of WET males were still courting, with 19 of them mating, whereas less than 25% of DRY males were courting and only one mated. CP deposition accounted for 4–6% of the mass lost by mating males, but hydration did not affect CP mass or water content. These findings suggest that, in years of low water availability, the number of courting males and the intensity of their courtship declines, thereby affecting sexual selection and conflict, at least within that year.

中文翻译：

---

脱水的雄性不太可能潜入交配池

争夺繁殖成功的动物的水合状态可能会对性选择的节奏和模式产生影响，这在水资源可用性环境波动增加的人群中可能很突出。我们使用红边吊袜带蛇作为模型系统，测试了在干旱年份补水对求偶、交配行为和交配插头 (CP) 生产的影响。在 3 天的交配试验中，补水雄性（WET 雄性，n = 45）优于未补水的对照组（DRY 雄性，n = 45）。超过 70% 的 WET 雄性交配，但只有 33% 的 DRY 雄性交配。作为一个群体，WET 雄性交配 79 次，而 DRY 雄性交配 28 次。在交配试验的最后一天，超过 70% 的 WET 雄性仍在求偶，其中 19 只交配，而只有不到 25% 的 DRY 雄性在求偶并且只有一只交配。CP 沉积占交配雄性损失的质量的 4-6%，但水合作用不影响 CP 质量或水含量。这些发现表明，在水资源匮乏的年份，求爱的雄性数量和求爱的强度都会下降，从而影响性选择和冲突，至少在当年是这样。