House Finches are familiar birds all across North America. Researchers have shown that the red coloration of males is produced from carotenoid pigments in the birds' diet. Male House Finches develop brighter plumage when they are growing in new feathers, if they eat more fruits containing carotenoids. Females prefer more brightly colored males. Redder males also attract females in better condition, and such a pair raises, on the average, more young. You can learn more at AAAS.org.

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