鸟类颜色多样性是演化生物学与动物生态学关注的热点问题之一。鸟类喙色展现出丰富的颜色多样性，但其演化模式仍未得到很好的研究。因此，本研究测量了鸡雁小纲462个物种的喙色，并基于物种系统进化树重建了雌雄喙色复杂度、类胡萝卜素色度预计物种性二色水平的祖先状态。进而在考虑物种系统进化关系的前提下，探究了食性、栖息地、社会环境、繁殖策略和性别等生态学因素对鸟类喙色的影响。祖先状态重建结果表明，鸡雁小纲共同祖先喙色为较浅的褐色，喙色复杂度中等，性二色程度较低。对喙色影响因素的分析发现，（1）雄性具有更高的喙色复杂度；（2）物种体型、分布区纬度、雌雄孵卵投入以及迁徙行为与喙的红色色度显著相关；（3）喙的性二色水平与分布中心纬度、集群和迁徙行为，体型性二态、雌雄孵卵投入及婚配制度等因素均显著相关。通过对鸡雁小纲物种喙色祖先状态的重建以及影响因素的分析，作者推测自然选择可能是鸡雁小纲物种喙色演化的主要驱动因素。

The diversity of avian colors is one of the hot issues in evolutionary biology and animal ecology. Avian bills represent rich color diversity, but its evolution pattern has not been well studied. Therefore, in this study, we measured the bill colors of 462 species in Galliformes and Anseriformes, and reconstructed the ancestral states of the color complexity, red chromaticity and sexual dichromatism of male and female bill. In addition, we explored the effects of life history traits considering the phylogeny of these species. The results of ancestral reconstruction shows that the common ancestor of Galloanserae species was light brown in bill color, medium in color complexity, and low in sexual chromatism. The analysis of potential influencing factors of bill color shows that: (1) males have greater color complexity; (2) red chromaticity of bill is significantly related to species size, latitude of distribution center, brooding division and migration; (3) sexual dichromatism is significantly related to the latitude of distribution center, whether it is cluster or not, whether it is migrate or not, and size dimorphism, brooding division and mating system. Based on the reconstruction of the ancestral state and the analysis of the influencing factors, we speculate that natural selection might be the main driver for the evolution of bill color in Galloanserae species.