1. Many seabird breeding colonies have recovered from heavy anthropogenic disturbance after conservation actions. The widely distributed red‐tailed tropicbird, Phaethon rubricauda, was used as a model species to assess potential anthropogenic impacts on the genetic diversity of breeding colonies in the Pacific Ocean.
2. Cytochrome c oxidase subunit I and control region sequences analyses were conducted across the range of the species in the Pacific Ocean. The study sites were at islands without human‐related disturbance (non‐impacted islands) and with human‐related disturbance (impacted islands). We hypothesized that (i) breeding colonies of the red‐tailed tropicbird on impacted islands have lower genetic diversity compared with colonies on non‐impacted islands, and (ii) breeding colonies of the red‐tailed tropicbird show significant fine and broad‐scale genetic structure across the Pacific Ocean. Bayesian skyline analyses were conducted to infer past changes in population sizes.
3. Genetic diversity was similar between impacted and non‐impacted islands. There was significant broad‐scale genetic structure among colonies separated by over 6,000 km, but a lack of significant fine‐scale genetic structure within Australasia and Hawai'i, although a significant level of differentiation was found within Chile with Φ_ST analyses. Skyline analyses showed that effective population sizes remained relatively constant through time, but experienced either a slight decrease or the end of an expansion event through the last 1,000 years. These changes may be related to the arrival of humans on Pacific islands.
4. Impacted islands may have received immigrants from other relatively close islands, buffering the loss of genetic diversity. However, it is also possible that colonies have retained ancestral variation or that a large effective population size coupled with a long generation time (13 years) has prevented the loss of genetic diversity in human‐impacted islands. Future research using higher‐resolution markers is needed to resolve the population genetic structure of the red‐tailed tropicbird in an ecological time‐scale.

中文翻译：

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太平洋中高度易变且受人类影响的海鸟的遗传多样性，种群结构和历史人口统计学：红尾热带鸟，Phaethon rubricauda

1. 在采取保护行动后，许多海鸟繁殖群体已从严重的人为干扰中恢复过来。广泛分布的红尾热带鸟（Phaethon rubricauda）被用作模型物种，以评估人为因素对太平洋繁殖种群遗传多样性的潜在影响。
2. 在太平洋的整个物种范围内进行了细胞色素C氧化酶亚基I和控制区序列分析。研究地点位于无人为干扰的岛屿（非受影响的岛屿）和受人为干扰的岛屿（受影响的岛屿）。我们假设（i）与未受影响的岛屿上的殖民地相比，在受影响的岛屿上的红尾热带鸟类的繁​​殖群体具有较低的遗传多样性，并且（ii）在红色的热带鸟类的繁​​殖群体中显示出明显的精细和广泛的遗传整个太平洋的结构。进行贝叶斯天际线分析以推断过去人口规模的变化。
3. 受灾和未受灾的岛屿之间的遗传多样性相似。有由6000余公里的分离群体中显著大规模的遗传结构，但缺乏内澳大利亚和夏威夷显著精细尺度遗传结构，虽然分化的显著水平内智利发现Φ _ST分析。天际线分析显示，有效人口规模在一段时间内保持相对恒定，但在过去的1000年中经历了略微下降或扩张事件结束。这些变化可能与人类到达太平洋岛屿有关。
4. 受灾岛屿可能已经从其他相对较近的岛屿接收了移民，从而缓冲了遗传多样性的丧失。但是，也有可能殖民地保留了祖先的变异，或者有效的种群数量庞大，加上较长的世代时间（13年），已经阻止了人类影响岛屿遗传多样性的丧失。需要使用更高分辨率的标记物进行未来的研究，以在生态时间尺度上解决红尾热带鸟类的种群遗传结构。