Birds are often coloured yellow, olive, orange or red by carotenoids, which are plant pigments that are ingested with food. Here we test whether there are consistent patterns of intraspecific geographic variation in male carotenoid‐based plumage coloration linked to latitude, temperature, precipitation and primary productivity. It has been suggested that patterns of geographic variation should be different for yellow, compared to the metabolically derived red carotenoid‐based coloration, but this has not been tested.

中文翻译：

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基于类胡萝卜素的羽毛颜色饱和度随澳大利亚雀形目的升高而增加

鸟类通常将类胡萝卜素染成黄色，橄榄色，橙色或红色，类胡萝卜素是食物中摄取的植物色素。在这里，我们测试男性类胡萝卜素的羽毛着色中是否存在与纬度，温度，降水和初级生产力相关的种内地理变异的一致模式。有人建议，与基于代谢的红色类胡萝卜素为基础的着色相比，黄色的地理变异模式应有所不同，但这尚未得到测试。