Sexually dimorphic ornamental traits are widely regarded as indicators of nutritional condition. However, variation of nutritional condition outside the reproductive and the ornament production seasons has rarely been considered, although it affects the generality of information content, especially for ornaments that may be used across the year. We measured several indicators of migratory and molt condition in male and female blackcaps (Sylvia atricapilla) during their autumn migration, and quantified their crown reflectance. We detected robust correlations between migratory and molt condition indices, and the correlation structure was similar in the two sexes. Furthermore, the across‐season measure of body condition was positively related to the darkness of the black crown in males, while being unrelated to reflectance traits of the reddish crown in females. Our results reinforce the possibility that some melanin‐based ornaments may be year‐round indicators of individual quality via their dependence on nutritional condition.

中文翻译：

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黑色素基装饰物的暗度与整个季节的营养状况呈正相关

两性性装饰性特征被广泛认为是营养状况的指标。但是，尽管它会影响信息内容的普遍性，特别是对于可能全年使用的装饰品，但很少考虑在生殖和装饰品生产季节之外的营养状况变化。我们测量了雄性和雌性黑cap（西尔维娅·阿特里卡皮拉（Sylvia atricapilla）的迁徙和蜕皮状况的几个指标）在秋季迁移期间，并量化了其冠状反射率。我们检测到迁徙和蜕皮状况指数之间存在稳固的相关性，并且两种性别的相关结构相似。此外，跨季节的身体状况测量与雄性黑冠的暗度成正相关，而与雌性红冠的反射特性无关。我们的结果加强了某些基于黑色素的装饰品通过依赖营养状况而成为个体品质全年指标的可能性。