Pairing success relative to male plumage redness and pigment symmetry in the house finch: temporal and geographic constancy

Male house finches (Carpodacus mexicanus) have carotenoid-based ornamental plumage coloration. In previous research it was shown that for a single population of house finches in a single year, males that paired were on average redder in plumage coloration than males that did not pair, and males with redder plumage tended to nest earlier than males with less red plumage. Here we show that these patterns continued over 6 years and at two widely separated locations. We also tested whether the symmetry of carotenoid-based crown pigmentation differed between paired and unpaired males and found that paired males have, on average, more perfect symmetry of crown pigmentation than males not paired. These observations support the idea that expression of carotenoid-based plumage coloration by males is a persistent and widespread criterion in female mate choice in the house finch.