Data from: Estimation of bumblebee queen dispersal distances using sibship reconstruction method

Dispersal ability is a key determinant of the propensity of an organism to cope with habitat fragmentation and climate change. Here we quantify queen dispersal in two common bumblebee species in an arable landscape. Dispersal was measured by taking DNA samples from workers in the spring and summer, and from queens in the following spring, at 14 sites across a landscape. The queens captured in the spring must be full sisters of workers that were foraging in the previous year. A range of sibship reconstruction methods were compared using simulated datasets including or no genotyping errors. The programme Colony gave the most accurate reconstruction and was used for our analysis of queen dispersal. Comparison of queen dispersion with worker foraging distances was used to take into account an expected low level of false identification of sister pairs which might otherwise lead to overestimates of dispersal. Our data show that Bombus pascuorum and B. lapidarius queens can disperse by at least 3 km and 5 km, respectively. These estimates are consistent with inferences drawn from studies of population structuring in common and rare bumblebee species, and suggest that regular gene flow over several kilometres due to queen dispersal are likely to be sufficient to maintain genetic cohesion of ubiquitous species over large spatial scales whereas rare bumblebee species appear unable to regularly disperse over distances greater than 10 km. Our results have clear implications for conservation strategies for this important pollinator group, particularly when attempting to conserve fragmented populations.扩散能力（dispersal ability）是决定生物应对生境破碎化（habitat fragmentation）与气候变化（climate change）倾向的关键因素。本研究针对农田景观（arable landscape）中的两种常见熊蜂（bumblebee）物种，量化了其熊蜂后（queen）的扩散能力。研究通过在14个样点开展采样分析：于春季与夏季采集工蜂（worker）的DNA样本，并于次年春季采集熊蜂后的DNA样本。春季捕获的熊蜂后，必然为前一年夏季觅食的工蜂的全同胞姐妹。我们采用包含或不包含基因分型错误（genotyping error）的模拟数据集，对一系列同胞关系重建（sibship reconstruction）方法进行了对比评估。结果显示，软件Colony的重建精度最高，因此被应用于本次熊蜂后扩散能力的分析。为抵消预期存在的低水平姐妹对误识风险——该风险可能导致扩散距离估算偏高——我们将熊蜂后扩散距离与工蜂觅食距离进行对比校正。研究数据表明，拟黄熊蜂（Bombus pascuorum）与红足熊蜂（B. lapidarius）的熊蜂后，其扩散距离分别至少可达3千米与5千米。上述估算结果与基于常见及稀有熊蜂物种种群结构的研究推论相符，表明：由熊蜂后扩散介导的常规跨千米基因流，足以维持广布熊蜂物种种群在大空间尺度上的遗传一致性；而稀有熊蜂物种则无法实现10千米以上的常规长距离扩散。本研究结果对这一重要传粉昆虫类群的保护策略具有明确的指导意义，尤其是在开展破碎化种群保护的实践中。