Adaptive radiations have helped shape how we view animal speciation, particularly classic examples such as Darwin's finches, Hawaiian fruitflies and African Great Lakes cichlids. These 'island' radiations are comparatively recent, making them particularly interesting because the mechanisms that caused diversification are still in motion. Here, we identify a new case of a recent bird radiation w...

Plumage is a complex component of the avian phenotype. The plumage of an individual is composed of numerous hierarchically arranged developmental and morphological modules. We present a hierarchical model of plumage that provides an intellectual framework for understanding the development and evolution of feathers. Independence, covariation, and interaction among plumage modules create numerous...

Colour ornamentation in animals is exceptionally diverse, but some colours may provide better signals of individual quality or more efficient visual stimuli and, thus, be more often used as sexual signals. This may depend on physiological costs, which depend on the mechanism of colour production (e.g. exogenously acquired colouration in passerine birds appears to be most sexually dichromatic). ...

Males in many bird species develop elaborate carotenoid-based plumage ornaments that play an important role as signals of individual quality in intraor intersexual selection. In the present study, we investigated which of several factors related to male condition and health affect the brightness and coloration of the carotenoid-based orange–red breeding plumage in males of the red bishop (Euple...

The broad palette of feather colours displayed by birds serves diverse biological functions, including communication and camouflage. Fossil feathers provide evidence that some avian colours, like black and brown melanins, have existed for at least 160 million years (Myr), but no traces of bright carotenoid pigments in ancient feathers have been reported. Insight into the evolutionary history of...

Sequence variation in the melanocortin-1 receptor (MC1R) gene explains color morph variation in several species of birds and mammals. Ruffs (Philomachus pugnax) exhibit major dark/light color differences in melanin-based male breeding plumage which is closely associated with alternative reproductive behavior. A previous study identified a microsatellite marker (Ppu020) near the MC1R locus assoc...

The avian plumage color gamut is the complete range of plumage colors, as seen by birds themselves. We used a tetrahedral avian color stimulus space to estimate the avian plumage color gamut from a taxonomically diverse sample of 965 plumage patches from 111 avian species. Our sample represented all known types of plumage coloration mechanisms. The diversity of avian plumage colors occupies onl...

A review is presented of the seven commonest types colour aberrations in birds together with suggestions for a standardised universal nomenclature to identify and distinguish these aberrations. These are: Leucism (congenital absence melanin-producing cells), Progressive Greying (progressive loss Albino (total melanin due lack key enzyme), Brown (incompletely coloured melanin), Ino (even less co...

Parasites influence the expression of secondary sexual traits and the health of infected individuals. We set out to test the influence of reputed exogenous parasites, plumage bacteria, including feather-degrading bacteria (FDB), on secondary sexual characteristics and body condition of wild adult eastern bluebirds Sialia sialis. Previous work has shown that FDB alter the coloration of structura...

Several studies have suggested that peak plumage reflectance in birds matches color preferences used in mate choice. We tested this hypothesis in adult satin bowerbird males that have a short-wavelength saturated blue-black plumage with a peak reflectance in the UV. We found that the chroma of the blue (405!480 nm), but not the peak reflecting UV (320! 400 nm) portion of the male plumage spectr...