Color differences among f t g

Full list of author information is available at the end of the articleFindings Plumage color variation in birds, within or between species, has long attracted the attention of evolutio-nary biologists and ecologists because of its potential importance in crypsis, adaptation in general, sexual selection and speciation [1]. Within species, plumage color variation is also an interesting example to stu-dy selective mechanisms for maintaining polymorph-ism in natural populations [2,3]. Feral pigeons show extreme plumage variation, which originated from artificial selection of domestic stock [4]. They show two major types of melanin-based colorations: black coloration, due to the deposition of eumelanic pig-ments in the feathers, and a less frequent ash-red coloration, due to the deposition of pheomelanic pigments [5]. Within each color type, feral pigeons also display continuous variation in the amount of melanin pigment present in feathers [4], from pure white to a full dark melanic coloration. Coloration in pigeons is highly heritable [4,6] and is only weakly influenced by environmental conditions [4]. Crosse