Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield, UK.
Bird Group, Department of Life Sciences, the Natural History Museum at Tring, Tring, UK.
Nat Ecol Evol. 2022 May;6(5):622-629. doi: 10.1038/s41559-022-01714-1. Epub 2022 Apr 4.
It has long been suggested that tropical species are generally more colourful than temperate species, but whether latitudinal gradients in organismal colourfulness exist remains controversial. Here we quantify global latitudinal trends in colourfulness (within-individual colour diversity) by collating and analysing a photographic dataset of whole-body plumage reflectance information for >4,500 species of passerine birds. We show that male and female birds of tropical passerine species are generally more colourful than their temperate counterparts, both on average and in the extreme. We also show that these geographic gradients can be explained in part by the effects of several latitude-related factors related to classic hypotheses for climatic and ecological determinants of organismal colourfulness. Taken together, our results reveal that species' colourfulness peaks in the tropics for passerine birds, confirming the existence of a long-suspected yet hitherto elusive trend in the distribution of global biodiversity.
长期以来，人们一直认为热带物种通常比温带物种更具色彩，但生物色彩的纬度梯度是否存在仍存在争议。在这里，我们通过整理和分析超过 4500 种雀形目鸟类的全身羽毛反射信息的摄影数据集，量化了全球色彩多样性（个体内部颜色多样性）的纬度趋势。我们表明，热带雀形目鸟类的雌雄个体通常比温带同类更具色彩，无论是平均水平还是极端水平都是如此。我们还表明，这些地理梯度可以部分解释为与经典假设有关的几种与纬度相关的因素的影响，这些因素与生物色彩的气候和生态决定因素有关。总的来说，我们的研究结果表明，在雀形目鸟类中，物种的色彩在热带达到顶峰，这证实了在全球生物多样性分布中存在一种长期以来一直被怀疑但迄今仍难以捉摸的趋势。
