Even as numerous studies have documented that the red and yellow coloration resulting
from the deposition of carotenoids serves as an honest signal of condition, the evolution of …

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 …

Pterins are one of the major sources of bright coloration in animals. They are produced
endogenously, participate in vital physiological processes and serve a variety of signalling …

For decades, scientists have noted connections between individual condition and
carotenoid-based coloration in terrestrial and aquatic animals. Organisms that produce more …

The shared-pathway hypothesis offers a cellular explanation for the connection between
ketocarotenoid pigmentation and individual quality. Under this hypothesis, ketocarotenoid …

Carotenoid pigments produce the yellow and red colors of birds and other vertebrates.
Despite their importance in social signaling and sexual selection, our understanding of how …

The exploration of hybrid zones and the intergenomic conflicts exposed through
hybridization provide windows into the processes of divergence and speciation. Sex …

Intense red colours in birds are often owing to ketocarotenoids (KCs). In many land birds,
KCs are oxidized from dietary yellow precursors, presumably by the avian carotenoid …

The past decades have provided valuable information on how animals age in the wild.
However, examples of male reproductive senescence are scarce. In particular, few studies …

Across many taxa, males use elaborate ornaments or complex displays to attract potential
mates. Such sexually selected traits are thought to signal important aspects of male 'quality' …