Data from: Population genetic structure and long-distance dispersal among seabird populations: implications for colony persistence

Dramatic local population decline brought about by anthropogenic-driven change is an increasingly common threat to biodiversity. Seabird life history traits that make them particularly vulnerable to such change, therefore understanding population connectivity and dispersal dynamics is vital for successful management. Our study used a 360 base-pair mitochondrial control region locus sequenced for 103 individuals and 18 nuclear microsatellite loci genotyped for 245 individuals to investigate population structure in the Atlantic and Pacific populations of the pelagic seabird, Leach’s storm-petrel Oceanodroma leucorhoa leucorhoa. This species is under intense predation pressure at one regionally important colony on St Kilda, Scotland, where a disparity between population decline and predation rates hints at immigration from other large colonies. AMOVA, FST, ΦST and Bayesian cluster analyses revealed no genetic structure among Atlantic colonies (Global ΦST = -0.02 P >0.05, Global FST = 0.003, P>0.05, STRUCTURE K = 1), consistent with either contemporary gene flow or strong historical association within the ocean basin. The Pacific and Atlantic populations are genetically distinct (Global ΦST = 0.32 P <0.0001, Global FST = 0.04, P <0.0001, STRUCTURE K = 2), but evidence for inter-ocean exchange was found with individual exclusion/assignment and population coalescent analyses. These findings highlight the importance of conserving multiple colonies at a number of different sites and suggest that management of this seabird may be best viewed at an oceanic scale. Moreover, our study provides an illustration of how long-distance movement may ameliorate the potentially deleterious impacts of localised environmental change, although direct measures of dispersal are still required to better understand this process.人为活动驱动的环境变化所引发的剧烈局域种群衰退，正日益成为威胁生物多样性的常见问题。海鸟的生活史特征使其对这类环境变化格外脆弱，因此解析种群连通性与扩散动态，对于实施高效的保护管理而言至关重要。本研究针对远洋海鸟白腰叉尾海燕（Leach’s storm-petrel，*Oceanodroma leucorhoa leucorhoa*）的大西洋与太平洋种群展开种群结构分析：对103个个体的360碱基对线粒体控制区（mitochondrial control region）位点进行测序，同时对245个个体的18个核微卫星（nuclear microsatellite）位点进行基因分型。该物种在苏格兰圣基尔达岛一处具有区域重要性的繁殖群中承受着极强的捕食压力，种群衰退速率与捕食压力间的失衡暗示该种群存在来自其他大型繁殖群的个体迁入。通过分子变异分析（AMOVA, Analysis of Molecular Variance）、固定指数（FST）、分化固定指数（ΦST）以及贝叶斯聚类分析，研究未发现大西洋各繁殖群间存在遗传结构（全局ΦST = -0.02，P>0.05；全局FST = 0.003，P>0.05；STRUCTURE分析最优聚类数K=1），这一结果与该洋盆内存在当代基因流或强烈的历史种群关联相符。太平洋与大西洋种群则呈现显著的遗传分化（全局ΦST = 0.32，P<0.0001；全局FST = 0.04，P<0.0001；STRUCTURE分析最优聚类数K=2），但通过个体排除/归属分析以及种群溯祖分析，发现了跨洋个体交换的证据。本研究结果凸显了在多个不同地点保护多个繁殖群的重要性，同时表明该海鸟的保护管理最佳尺度应设定为洋盆尺度。此外，本研究阐释了长距离扩散如何缓解局域环境变化所带来的潜在有害影响，尽管仍需开展扩散的直接观测以进一步解析这一过程。