Understanding the genetic basis of convergence at broad phylogenetic scales remains a key challenge in biology. Kingfishers (Aves: Alcedinidae) are a cosmopolitan avian radiation with diverse colors, diets, and feeding behaviors—including the archetypal plunge-dive into water. Given the sensory and locomotor challenges associated with air-water transitions, kingfishers offer a powerful opportunity to explore the effects of convergent behaviors on the evolution of genomes and phenotypes, as well as direct comparisons between continental and island lineages. Here, we use whole-genome sequencing of 30 diverse kingfisher species to identify the genomic signatures associated with convergent feeding behaviors. We show that species with smaller ranges (i.e., on islands) have experienced stronger demographic fluctuations than those on continents, and that these differences have influenced the dynamics of molecular evolution. Comparative genomic analyses reveal positive selection and genomic convergence in brain and dietary genes in plunge-divers. These findings enhance our understanding of the connections between genotype and phenotype in a diverse avian radiation.

了解广泛系统发育尺度上趋同的遗传基础仍然是生物学中的一个关键挑战。翠鸟（鸟纲：翠鸟科）是一种世界性鸟类，具有多种颜色、饮食和摄食行为，包括典型的潜入水中。考虑到与空气-水转换相关的感觉和运动挑战，翠鸟提供了一个强大的机会来探索趋同行为对基因组和表型进化的影响，以及大陆和岛屿谱系之间的直接比较。在这里，我们使用 30 种不同翠鸟物种的全基因组测序来识别与趋同摄食行为相关的基因组特征。我们表明，范围较小（即岛屿上）的物种比大陆上的物种经历了更强的人口波动，并且这些差异影响了分子进化的动态。比较基因组分析揭示了潜水员大脑和饮食基因的正向选择和基因组趋同。这些发现增强了我们对不同鸟类辐射中基因型和表型之间联系的理解。