MELANIN CONCENTRATIONS IN FEATHERS FROM WILD AND DOMESTIC PIGEONS

Vanes from secondary remiges and greater coverts (i.e., feathers that form the wing bars of the wild coloration type) were analyzed for their eumelanin and pheomelanin contents. The samples were taken from wild rock pigeons and from domestic breeds representing different coloration types of known genetic background. The bars in the wild rock pigeons and in similarly colored domestic birds are eumelanic but also contain some pheomelanin. In ash red (BA) pigeons the bars are pheomelanic with drastically reduced eumelanin concentrations, and in brown (b) specimens they are of a pheomelanic to mixed type. Mutant S (spread) eliminates the differences in the melanin concentrations between the bars and the adjacent areas, resulting in a uniform coloration. Its effects on eumelanin and pheomelanin contents vary in dependence from the alleles at the color locus and from other genes. Recessive red (e e) pigeons are pheomelanic. The effects of the dilution factor (d) cannot be described by a single dilution index but depend on combination with other genes. Our findings are consistent with the idea that the greater variation of coloration in domesticated animals than in their wild ancestors is caused by mutations that affect the distribution, amounts, and proportions of pigments but not their chemistry. © 1992 Oxford University Press.