Multiple ornaments correlate with aspects of condition and behaviour in female northern cardinals, Cardinalis cardinalis

Abstract

Male ornamentation in socially monogamous birds has been shown to provide information to potential mates on aspects of condition and behaviour. We studied female ornamentation in the socially monogamous, biparental northern cardinal to determine whether expressions of multiple ornaments correlate with aspects of female condition and behaviour. Expressions of the ornamental red-orange bill, red underwing feathers, head crest and blackish face mask were compared to several measures of condition, parental behaviour and intrasexual aggression. Red-orange bill colour of females was correlated with both body size and an index of body condition. Redness of the underwing feathers was correlated with body size, body condition, date of first nest produced and reproductive success. Face mask expression was correlated with both nestling feeding rate and level of intrasexual aggression. The length of head crest feathers did not correlate with any measured aspect of condition or behaviour. These results are consistent with the hypothesis that ornaments in female cardinals provide redundant information to prospective mates on aspects of female condition and behaviour.