The colorful phenotypes of birds have long provided rich source material for evolutionary
biologists. Avian plumage, beaks, skin, and eggs—which exhibit a stunning range of cryptic …

Birds display a rainbow of eye colours, but this trait has been little studied compared with
plumage coloration. Avian eye colour variation occurs at all phylogenetic scales: it can be …

Thirty years of research has made carotenoid coloration a textbook example of an honest
signal of individual quality, but tests of this idea are surprisingly inconsistent. Here, to …

Colourful traits in females are suggested to have evolved and be maintained by sexual
selection. Although several studies have evaluated this idea, support is still equivocal …

Plumage is among the most well-studied components of integumentary colouration.
However, plumage conceals most skin in birds, and as a result the presence, evolution and …

Unlike wild and domestic canaries (Serinus canaria), or any of the three dozen species of
finches in genus Serinus, the domestic urucum breed of canaries exhibits bright red bills and …

Evolutionary biologists have long been interested in understanding the factors that promote
diversification in organisms, often focussing on distinct and/or conspicuous phenotypes with …

In the past 30 years, carotenoid‐based animal signals have been an intense focus of
research because they can potentially broadcast an honest reflection of individual …

When constraints on antipredator coloration shift over the course of development, it can be
advantageous for animals to adopt different color strategies for each life stage. Many …

Female ornaments have long been considered non-functional, but a paradigm shift has
occurred over the 2 last decades. The adaptive nature of female ornaments is now widely …