Data for: Sex-biased infections scale to population impacts for an emerging wildlife disease

Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios, and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity, and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behavior. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.

人口统计学因素是塑造传染病传播动态的核心基础。构成种群结构的各类特征（如年龄与性别），可对疾病传播模式、感染强度及种群结局产生影响。然而现有研究极少将这些过程从个体层面衔接至种群尺度的效应。此外，疾病相关人口统计学差异背后的潜在机制往往尚不明确。本研究针对蝙蝠的多宿主真菌病——白鼻综合征（White-nose Syndrome），探究其性别偏向性感染特征，并关联不同性别间的疾病相关死亡率、种群性别比例失衡情况，以及感染性别差异背后的潜在机制。研究团队在7年间的42个监测位点中，收集了5种蝙蝠的宿主性状、感染强度及存活数据。结果显示，5个蝙蝠物种的雌性个体感染程度均显著高于雄性；同时雌性个体的冬季表观存活率更低，且随时间推移在种群中所占比例持续偏低。值得注意的是，雌性偏向的感染特征在冬眠早期即已显现，其潜在驱动因素可能为雌雄个体在秋季交配行为中的差异：雄性蝙蝠在秋季更为活跃，这或可抑制这类低温生长真菌的增殖。雌性蝙蝠承受的更高疾病压力，可能通过限制种群招募率、提升阿利效应（Allee Effect）发生风险，对冬眠季之外的蝙蝠种群产生级联影响。