Urbanisation impacts plumage colouration in a songbird across Europe: evidence from a correlational, experimental, and meta-analytical approach

Urbanisation is increasing rapidly across the globe, transforming landscapes, presenting organisms with novel challenges, shaping phenotypes, and impacting fitness. Urban individuals are claimed to have duller tones in carotenoid-based traits, the so-called ″urban dullness″ phenomenon. However, at the intra-specific level, this generalisation is surprisingly inconsistent and often based on examples from few populations or a limited geographic area. Here, combining correlational, experimental, and meta-analytical results from a common songbird, the great tit (Parus major), we investigated carotenoid-based plumage coloration in urban and forest populations across Europe. We find that, as predicted, urban individuals are paler than forest individuals, although there are large population-specific differences in the magnitude of the urban-forest contrast in colouration. Our meta-analysis indicates a non-significant effect of environmental pollution on carotenoid-based plumage for the species..., Great tit plumage carotenoid colouration (chroma and brightness) measurements from 5 urban/forest population pairs, in addition to cross-sectional data, a cross-fostering experiment for one urban/forest population and a meta-analysis on the effects of anthropogenic stressors (urbanisation and pollution) on great tit plumage colouration.,

全球城市化进程正快速推进，它重塑地表景观，为各类生物带来全新生存挑战，塑造生物表型，并影响其适合度。有研究表明，城市环境中的个体在类胡萝卜素（carotenoid）依赖型性状上的色彩更为黯淡，即所谓的“城市黯淡（urban dullness）”现象。然而在种内尺度下，这一普遍性结论却出人意料地缺乏一致性，且多数相关研究仅基于少数种群或有限地理区域的案例。本研究以广布鸣禽大山雀（Parus major）为研究对象，整合相关性研究、实验及元分析结果，对欧洲范围内城市与森林种群的类胡萝卜素依赖型羽色展开了调查。研究结果显示，正如预期那般，城市种群个体的羽色较森林种群更为浅淡，尽管不同种群间羽色的城乡差异幅度存在显著异质性。本研究的元分析结果表明，环境污染对该物种类胡萝卜素依赖型羽色的影响并不显著。本数据集包含5组城乡种群配对的大山雀羽色类胡萝卜素色度与亮度测量数据，此外还附带横断面调查数据、一组城乡种群的交叉抚育实验数据，以及关于人为胁迫因子（城市化与污染）对大山雀羽色影响的元分析数据集。