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.

由人为驱动的变化所引发的剧烈局地种群衰退，正日益成为生物多样性面临的普遍威胁。海鸟的生活史特征使其尤其易受此类变化影响，因此解析种群连通性与扩散动态对于开展有效的保护管理至关重要。本研究针对远洋海鸟白叉尾海燕（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，共对103个个体的360碱基对线粒体控制区位点进行测序，并对245个个体的18个核微卫星位点进行基因分型。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，其种群衰退速率与捕食速率之间的差异暗示存在来自其他大型繁殖群的个体迁入。分子方差分析（AMOVA）、F统计量（FST）、Φ统计量（ΦST）以及贝叶斯聚类分析结果显示，大西洋各繁殖群间不存在遗传结构（全局ΦST = -0.02，P>0.05；全局FST = 0.003，P>0.05；STRUCTURE分析的最优聚类数K=1），这与该洋盆内存在当代基因流或较强的历史种群关联相一致。太平洋与大西洋种群在遗传上存在显著分化（全局ΦST = 0.32，P<0.0001；全局FST = 0.04，P<0.0001；STRUCTURE分析的最优聚类数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，并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地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研究，才能更深入地理解这一过程。