Sexual dimorphism or dichromatism has long been considered the result of sexual selection. However, for many organisms the degree to which sexual dichromatism occurs has been determined within the confines of human perception. For birds, objective measures of plumage color have revealed previously unappreciated sexual dichromatism for several species. Here we present an unbiased assessment of p...

BACKGROUND In complex sexual signaling systems such as plumage color, developmental or genetic links may occur among seemingly distinct traits. However, the interrelations of such traits and the functional significance of their integration rarely have been examined. METHODOLOGY/PRINCIPAL FINDINGS We investigated the parallel variation of two reflectance descriptors (brightness and UV chroma) ...

Why do some bird species show dramatic sexual dichromatism in their plumage? Sexual selection is the most common answer to this question. However, other competing explanations mean it is unwise to assume that all sexual dichromatism has evolved by this mechanism. Even if sexual selection is involved, further work is necessary to determine whether dichromatism results from competition amongst ri...

Sexual dichromatism in birds is often attributed to selection for elaboration in males. However, evolutionary changes in either sex can result in plumage differences between them, and such changes can result in either gains or losses of dimorphism. We reconstructed the evolution of plumage colors in both males and females of species in Maluridae, a family comprising the fairy-wrens (Malurus, Cl...

The performance of animal in a given environment differs between and within species, breeds strains genotypes, as result genetic variation. A total 200 turkeys comprising 50 exotic (Nicholas white) each Nigerian locally adapted (black, white lavender) was used to investigate variation body weight some biometric traits turkey at the Turkey Breeding unit Teaching Research Farm Ambrose Alli Univer...

Flamingos (Phoenicopteriformes) are obligate colonial species that nest in large colonies, with monogamous pairs rearing a single chick following synchronised group courtship display. Within this relatively simplistic behavioural description, deviations from these social and reproductive norms apparent. Same sex pairings, multi-bird relationships extra pair copulations documented the literature...

Recent behavioural experiments have shown that birds use ultraviolet (UV)-reflective and fluorescent plumage as cues in mate choice. It remains controversial, however, whether such UV signals play a special role in sexual communication, or whether they are part of general plumage coloration. We use a comparative approach to test for a general association between sexual signalling and either UV-...

Elaborate secondary sexual traits, such as the ornamental plumage of birds, may be favored by female choice because they serve as honest indicators of male quality. Elaborate traits are thought to be honest signals because they are expensive to produce and increase predation risk. Here we investigate another potential cost of elaborate traits, i.e., the time and energy required to maintain them...

The tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes have been accepted as major genes involved in the plumage pigmentation of chickens. The co-segregation of plumage coloration and sequence polymorphism in TYR and MC1R genes were investigated using an intercross between black and white plumage color types of the Dongxiang blue-shelled chicken. Profiles of plumage color changing and ge...