Szukana fraza: [Abstract = "Birds were provided with artificial diets containing either 100%, 50% or 10% of the recommended level of copper. Dietary copper did not affect the size of the black breast patch, the most obvious melanin\-based plumage trait in this species, nor did it affect the reflectance of the black feathers. In sum, we reject the hypothesis that dietary copper limits the size or blackness of the breast patch of the male house sparrow."]

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