A female melanin ornament signals offspring fluctuating asymmetry in the barn owl.

Sex-linked inheritance, genetic correlations and sexual dimorphism in three melanin-based colour traits in the barn owl.

Theory states that genes on the sex chromosomes have stronger effects on sexual dimorphism than genes on the autosomes. Although empirical data are not necessarily consistent with this theory, this situation may prevail because the relative role of sex-linked and autosomally inherited genes on sexual dimorphism has rarely been evaluated. We estimated the quantitative genetics of three sexually ...

Signalling value of maternal and paternal melanism in the barn owl: implication for the resolution of the lek paradox

Secondary sexual characters often signal qualities such as physiological processes associated with resistance to various sources of stress. When the expression of an ornament is not sex-limited, we can identify the costs and benefits of displaying a trait that is typical of its own sex or of the other sex. Indeed, the magnitude and sign of the covariation between physiology and the extent to wh...

Dominant nestlings displaying female-like melanin coloration behave altruistically in the barn owl

Regulation of stress response is heritable and functionally linked to melanin-based coloration.

Sexual selection theory posits that ornaments can signal the genetic quality of an individual. Eumelanin-based coloration is such an ornament and can signal the ability to cope with a physiological stress response because the melanocortin system regulates eumelanogenesis as well as physiological stress responses. In the present article, we experimentally investigated whether the stronger stress...

Age-related change in melanin-based coloration of Barn owls (Tyto alba): females that become more female-like and males that become more male-like perform better

Ornament expression fluctuates with age in many organisms. Whether these changes are adaptively plastic is poorly known. In order to understand the ultimate function of melanin-based ornaments, we studied their within-individual fluctuations and their covariation with fitness-related traits. In barn owls (Tyto alba), individuals vary from reddish-brown pheomelanic to white, and from immaculate ...