Habitat fragmentation is a major extinction driver. Despite dramatically increasing fragmentation across the globe, its specific impacts on population connectivity across species with differing life histories remain difficult to characterize, let alone quantify. Here, we investigate patterns of population connectivity in six songbird species from Singapore, a highly fragmented tropical rainforest island. Using massive panels of genome‐wide single nucleotide polymorphisms across dozens of samples per species, we examined population genetic diversity, inbreeding, gene flow and connectivity among species along a spectrum of ecological specificities. We found a higher resilience to habitat fragmentation in edge‐tolerant and forest‐canopy species as compared to forest‐dependent understorey insectivores. The latter exhibited levels of genetic diversity up to three times lower in Singapore than in populations from contiguous forest elsewhere. Using dense genomic and geographic sampling, we identified individual barriers such as reservoirs that effectively minimize gene flow in sensitive understorey birds, revealing that terrestrial forest species may exhibit levels of sensitivity to fragmentation far greater than previously expected. This study provides a blueprint for conservation genomics at small scales with a view to identifying preferred locations for habitat corridors, flagging candidate populations for restocking with translocated individuals and improving the design of future reserves.

中文翻译：

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六种鸣鸟在分散的东南亚景观中存在细小的连通障碍。


栖息地破碎化是灭绝的主要驱动因素。尽管全球范围内的碎片化程度急剧增加，但其对具有不同生活史的物种之间的种群连通性的具体影响仍然难以表征，更不用说量化了。在这里，我们调查了新加坡这个高度分散的热带雨林岛屿的六种鸣禽的种群连通性模式。我们使用每个物种数十个样本的大量全基因组单核苷酸多态性面板，沿着一系列生态特异性检查了种群遗传多样性、近亲繁殖、基因流和物种之间的连通性。我们发现，与依赖森林的林下食虫动物相比，耐边缘物种和林冠物种对栖息地破碎化的恢复能力更高。新加坡的后者表现出的遗传多样性水平比其他地方邻近森林的种群低三倍。通过密集的基因组和地理采样，我们确定了诸如水库之类的个体障碍，可以有效地最大限度地减少敏感的林下鸟类的基因流，揭示陆地森林物种对破碎化的敏感性可能远远高于之前的预期。这项研究为小规模的保护基因组学提供了蓝图，旨在确定栖息地走廊的首选位置，标记候选种群以重新放养易位个体，并改进未来保护区的设计。