Data from: Evaluation of sex differences in the stopover behavior and postdeparture movements of wood-warblers

Sex differences in the behaviors underlying avian protandry, where males arrive at breeding areas earlier than females, are still poorly understood for most species. We tested for sex differences in stopover behavior, refueling rates, and post-departure movements during spring migration in two consecutive years in wood-warblers (Parulidae) at a coastal site on Lake Erie, Ontario, using automated radio telemetry (black-throated blue warblers Setophaga caerulescens and magnolia warblers S. magnolia) and analysis of plasma metabolites as indicators of refueling (magnolia warblers, American redstarts S. ruticilla and common yellowthroats Geothylpis trichas). We found no differences between sexes in stopover duration or refueling index, although we did find subtle sex differences in the onset and end of diel activity, with males beginning to forage earlier in the morning than females and male magnolia warblers ending diel activity later in the evening than female magnolia warblers. More obvious were annual differences in stopover duration and the timing of diel activity, with shorter stopovers and an earlier onset of diel activity in the year with a warmer spring. We also did not find any evidence that sexes differed in their post-departure ground speeds or migration routes. In wood-warblers, males and females can differ in some aspects of their stopover ecology, but these differences are likely context dependent and likely do not drive protandry in a consistent way.关于鸟类雄性先熟迁徙（avian protandry，即雄性较雌性更早抵达繁殖区域）的行为机制差异，目前多数鸟类物种的相关研究仍存在大量认知空白。本研究于加拿大安大略省伊利湖沿岸的监测站点，以连续两年的周期开展春季迁徙相关研究，旨在检验森莺科（Parulidae）鸟类的停歇行为、燃料补给速率以及离境后移动模式的性差异：针对黑喉蓝林莺（Setophaga caerulescens）与木兰林莺（S. magnolia）采用自动化无线电遥测技术（automated radio telemetry）采集数据，并通过分析血浆代谢物（plasma metabolites）作为燃料补给状态的检测指标，观测对象同时涵盖美洲红尾林莺（S. ruticilla）与普通黄喉林莺（Geothlypis trichas）。研究结果显示，雌雄个体在停歇时长与燃料补给指数方面并无显著差异，但在昼夜活动节律的起始与结束节点上存在细微性差异：雄性林莺会较雌性更早于清晨开启觅食活动，而木兰林莺的雄性个体则会较雌性更晚结束当日的昼夜活动。更为突出的差异则体现在年度间的变化：暖春年份的停歇时长更短，且昼夜活动节律的起始时间更早。此外，本研究未发现雌雄个体在离境后地面飞行速度或迁徙路线上存在差异。综上，森莺科鸟类的雌雄个体在停歇生态的部分维度上确存在性差异，但这类差异大概率具有情境依赖性，且无法持续驱动雄性先熟迁徙现象的发生。