Data from: A shortage of males causes female reproductive failure in yellow ground squirrels

Sexual conflict theory suggests that female breeding success is strongly influenced by individual life history and environmental conditions and is much less affected by mate availability. Female mating failure due to a shortage of males remains poorly studied and understood. We present data on the effects of male availability on female breeding success in a wild colony of yellow ground squirrels (Spermophilus fulvus). A female’s probability of breeding increased with the local density of males and was higher with higher male-biased operational sex ratio (OSR) but was independent of local female density, female age, and body condition, which are factors commonly assumed to influence female reproduction. The positive effect of male availability (as measured by OSR) on female breeding success was consistent across the years, and we conclude that male limitation contributes to female mating failure. This pattern, which is not commonly recorded in species with conventional sex roles, can be explained by a combination of sociodemographic and life history traits (sex differences in age of maturation, female-skewed adult sex ratio and seasonally varying OSR, solitary living at low population density, and low mobility of females combined with mate-searching tactics of males) that are not confined to S. fulvus. Our findings indicate that the role of female mating failure (due to a shortage of males) in shaping mammalian life history may be underestimated.性冲突理论（Sexual conflict theory）指出，雌性繁殖成功率主要受个体生活史与环境条件的调控，而受配偶可获得性的影响相对微弱。因雄性短缺导致的雌性交配失败现象，迄今仍未得到充分研究与阐释。本研究针对黄地松鼠（Spermophilus fulvus）的野生种群，探究了雄性可获得性对雌性繁殖成功率的影响。研究发现，雌性的繁殖概率随当地雄性密度升高而上升，且在雄性偏向的操作性别比（operational sex ratio, OSR）更高时更高；但该概率与当地雌性密度、雌性年龄及身体状况无关——而这些因素通常被认为会影响雌性繁殖。雄性可获得性（以操作性别比衡量）对雌性繁殖成功率的正向效应在各年份间保持一致，由此我们推断，雄性限制是导致雌性交配失败的重要因素。这种模式在具有典型性别角色的物种中并不常见，其可通过以下社会人口学与生活史特征的组合得到解释：性成熟年龄的性别差异、雌性偏倚的成年性别比与季节性变化的操作性别比、低密度种群下的独居生活、雌性较低的移动能力，以及雄性的配偶搜寻策略——这些特征并非仅存在于黄地松鼠中。本研究结果表明，因雄性短缺导致的雌性交配失败，在塑造哺乳动物生活史过程中的作用可能被低估了。