Carotenoid pigmentation in birds’ plumage is considered an honest indicator of phenotypic quality, and thus a target of sexual selection. But carotenoids also fulfill essential physiological functions, and therefore, carotenoids should only appear in plumage if they are in excess of those needed physiologically. We explored the presence of carotenoid-based plumage coloration in columbids and it...

in vitro and in vivo can be attributed to crowding? The answer to this question depends upon the particular reaction and the microscopic environment in which the reaction is taking place. Early demonstrations of the large effect of crowding on association equilibria and rates were based upon studies of the behavior of mutant and normal hemoglobins in erythrocytes. Hemolysate is a fairly simple ...

To increase plumage color uniformity and understand the genetic background of Korean chickens, we performed a genome-wide association study of different plumage color in Korean native chickens. We analyzed 60K SNP chips on 279 chickens with GEMMA methods for GWAS and estimated the genetic heritability for plumage color. The estimated heritability suggests that plumage coloration is a polygenic ...

Plumage coloration in birds serve multiple purposes, including species recognition, sexual selection cues, and camouflage. Differences in plumage coloration can be used to infer evolutionary relationships, identify distinct taxonomic units, and characterize geographic variation. With the advent of electronic devices to quantify plumage coloration quickly and reliably, taxonomic or geographic di...

Carotenoids cannot be synthesized by birds and thus have to be ingested with food, suggesting that carotenoid-based plumage coloration is environmentally determined. However signaling functions ascribed to plumage imply that plumage coloration is the outcome of an evolutionary process based on genetic variation. By means of a cross-fostering design we show significant effects of both a common r...

BACKGROUND Sexual signals, such as bright plumage coloration in passerine birds, reflect individual quality, and testosterone (T) may play a critical role in maintaining signal honesty. Manipulations of T during molt have yielded mixed effects on passerine plumage color, in most cases delaying molt or leading to production of drab plumage. However, the majority of these studies have been conduc...

The ability to perceive the near ultraviolet part of the light spectrum (the wavelength 320–400 nm) has been detected in many bird species. This ability is an important bird sense. The ecological importance of UV perception has been studied mainly in the context of intraand inter-sexual signalling, common species communication and also in foraging. Some birds of prey use UV reflectance in their...

Iridescence is produced by coherent scattering of light waves from alternating layers of materials of different refractive indices. In birds, iridescent colours are produced by feather barbules when light is scattered from alternating layers of keratin, melanin and air. The structure and organization of these layers, and hence the appearance of bird species with different types of plumage iride...