López-Idiáquez David, Doutrelant Claire, Pearman Peter B
Department of Plant Biology and Ecology, Faculty of Sciences and Technology, University of the Basque Country (UPV/EHU), Leioa, Bizkaia, Spain.
CEFE, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France.
J Anim Ecol. 2025 Jul;94(7):1461-1473. doi: 10.1111/1365-2656.70077. Epub 2025 Jun 12.
Avian plumage colouration is an iconic example of trait variability among species. Sexual, social and natural selection, and the environmental variables modulating them are the main drivers of this variability. So far, most research exploring environmental effects on the variability of plumage colouration has focused on the variation in overall plumage darkness. Research on other aspects of colour variation, such as the diversity of colours exhibited by a species (i.e. colour complexity), is limited and has produced inconsistent results. Furthermore, colour complexity has mostly been analysed at the whole-plumage level, despite the possibility that the colour complexity of different plumage patches may be sensitive to different environmental factors. Here, we quantify male and female colouration in 58 species of the family Paridae, and use multi-predictor Bayesian phylogenetic mixed models to estimate the relationship of colouration with biotic and climatic variables that quantify environment, and with several species-specific characteristics. We consider both the colouration of the whole plumage and the colouration of four separate colour patches (head, chest, back and wing). We find that Paridae species in climates with intermediate temperatures present more complex colouration than do species in warmer/colder climates. In addition, males, relatively small species, and species with relatively greater sexual dichromatism have more complex plumage colouration. We find that the numbers of predators and sympatric conspecifics are more associated with female colouration than with male colouration. Finally, the strength of the associations with colour complexity is specific to each plumage region: species recognition, beak size and climate variables related to competition for reproductive resources (i.e. precipitation seasonality) are more strongly associated with colouration complexity of the head and breast than with that of the back and wing. Overall, our results illustrate the importance of climatic and social variables, the link between colour complexity and dichromatism in both sexes, and the analysis of distinct plumage areas for understanding global patterns of colouration complexity and the processes that promote them.
鸟类羽毛颜色是物种间性状变异的一个标志性例子。性选择、社会选择和自然选择，以及调节它们的环境变量是这种变异的主要驱动因素。到目前为止，大多数探索环境对羽毛颜色变异影响的研究都集中在整体羽毛黑暗度的变化上。对颜色变异其他方面的研究，如一个物种所呈现颜色的多样性（即颜色复杂性），则较为有限，且结果并不一致。此外，尽管不同羽毛斑块的颜色复杂性可能对不同环境因素敏感，但颜色复杂性大多是在整个羽毛水平上进行分析的。在这里，我们对山雀科58个物种的雄性和雌性羽毛颜色进行了量化，并使用多预测变量贝叶斯系统发育混合模型来估计颜色与量化环境的生物和气候变量以及几个物种特异性特征之间的关系。我们既考虑了整个羽毛的颜色，也考虑了四个单独颜色斑块（头部、胸部、背部和翅膀）的颜色。我们发现，处于中等温度气候下的山雀科物种比处于较温暖/寒冷气候下的物种呈现出更复杂的颜色。此外，雄性、相对较小的物种以及具有相对较大两性异色性的物种具有更复杂的羽毛颜色。我们发现，捕食者和同域同种个体的数量与雌性羽毛颜色的关联比与雄性羽毛颜色的关联更强。最后，与颜色复杂性的关联强度因每个羽毛区域而异：物种识别、喙大小以及与生殖资源竞争相关的气候变量（即降水季节性）与头部和胸部颜色复杂性的关联比与背部和翅膀颜色复杂性的关联更强。总体而言，我们的结果说明了气候和社会变量的重要性、两性颜色复杂性与异色性之间的联系，以及对不同羽毛区域进行分析对于理解全球颜色复杂性模式及其促进过程的重要性。
