Contrasting patterns of selection on the size and coloration of a female plumage ornament in common yellowthroats

摘要: Females often possess ornaments that appear smaller and duller than homologous traits in males. These may arise as nonfunctional by-products of sexual selection males cause negative viability or fecundity females proportion to the cost their production maintenance. Alternatively, female function signals quality are maintained by social selection. In a 4-year study 83 common yellowthroats (Geothlypis trichas) 222 young, we found strong on yellow bib, carotenoid-based plumage ornament is target with larger bibs were older, more fecund bibs. However, bib size positively covaried total brightness carotenoid chroma, aspects coloration under colourful laid fewer eggs first clutch, likely suffer brood loss due predation less return area. Selection against limits value indicator constrain elaboration attributes