Estimations on the influence of evolutionary and ecological forces as drivers of population gene diversity and genetic structure have been performed on a growing number of colonial seabirds, but many remain poorly studied. In particular, the population genetic structure of storm-petrels (Hydrobatidae) has been evaluated in only a few of the 24 recognized species. We assessed the genetic diversity and population structure of the Black Storm-Petrel (Hydrobates melania) and the Least Storm-Petrel (Hydrobates microsoma) in the Gulf of California. The two species were selected because they are pelagic seabirds with comparable ecological traits and breeding grounds. Recent threats such as introduced species of predators and human disturbance have resulted in a decline of many insular vertebrate populations in this region and affected many different aspects of their life histories (ranging from reproductive success to mate selection), with a concomitant loss of genetic diversity. To elucidate to what extent the population genetic structure occurs in H. melania and H. microsoma, we used 719 base pairs from the mitochondrial cytochrome oxidase c subunit I gene. The evaluation of their molecular diversity, genetic structure, and gene flow were performed through diversity indices, analyses of molecular and spatial variance, and isolation by distance (IBD) across sampling sites, respectively. The population genetic structure (via AMOVA and SAMOVA) and isolation by distance (pairwise p-distances and FST/1–FST (using ΦST) were inferred for H. microsoma. However, for H. melania evidence was inconclusive. We discuss explanations leading to divergent population genetic structure signatures in these species, and the consequences for their conservation.

中文翻译：

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加利福尼亚湾黑色风暴海燕和最小风暴海燕共存种群的不同遗传结构

已经对越来越多的殖民地海鸟进行了关于进化和生态力量作为种群基因多样性和遗传结构驱动因素的影响的估计，但许多研究仍然很少。特别是，仅在 24 种公认物种中的少数物种中评估了风暴海燕（Hydrobatidae）的种群遗传结构。我们评估了加利福尼亚湾的黑色风暴海燕 (Hydrobates melania) 和最小风暴海燕 (Hydrobates microsoma) 的遗传多样性和种群结构。选择这两个物种是因为它们是具有可比生态特征和繁殖地的远洋海鸟。最近的威胁，例如引入的捕食者物种和人类干扰，导致该地区许多岛屿脊椎动物种群数量下降，并影响了它们生活史的许多不同方面（从繁殖成功到配偶选择），并伴随着遗传多样性的丧失. 为了阐明黑猩猩和微粒体中种群遗传结构的发生程度，我们使用了来自线粒体细胞色素氧化酶 c 亚基 I 基因的 719 个碱基对。它们的分子多样性、遗传结构和基因流的评估分别通过多样性指数、分子和空间方差分析以及跨采样点的距离隔离 (IBD) 进行。