Plumage coloration is generally perceived as a static trait and therefore not a good indicator of current condition. However, changing of feather colors after molt does occur and may have important implications for signal function and sexual selection. We studied longitudinal changes in blue tit...

Intraspecific sexual and social communications are among the most important factors shaping costly color traits in birds. Condition capture models assume that only animals in superior condition can develop and maintain a colorful plumage. Although there is good evidence that carotenoid-based...