Melanin- versus carotenoid-based sexual signals: is the difference really so black and red?
A large number of coloured sexually selected ornamental traits in the animal kingdom are based on carotenoid and melanin pigments. The biochemical differences between these two classes of pigment, together with their different physiological roles, have led to the general belief that there will be a fundamental difference in the way in which they are […]
Dominant nestlings displaying female-like melanin coloration behave altruistically in the barn owl
When competing over parental resources, young animals may be typically selfish to the point of siblicide. This suggests that limited parental resources promote the evolution of sibling competition rather than altruistic or cooperative behaviours. In striking contrast, we show here that in 71% of experimental three-chick broods, nestling barn owls, Tyto alba, gave food to […]
Phenotypic correlates of melanization in two Sceloporus occidentalis (Phrynosomatidae) populations: Behavior, androgens, stress reactivity, and ectoparasites
Mechanisms underlying production of animal coloration can affect key traits besides coloration. Melanin, and molecules regulating melanin, can directly and indirectly affect other phenotypic traits including aggression, stress-reactivity, and immune function. We studied correlation of melanization with these other traits, comparing within- and between-population differences of adult male western fence lizards, Sceloporus occidentalis. We compared […]