Note on a bronze-bourbon red mosaic

A mosaic occurred in theF 2 generation of a cross of a Bronze male on a Bourbon Red female. This bird was bronze on the head, neck, shoulders, tail and part of the rump with some patches of bronze feathers surrounded by red on the wings. The rest of the bird was covered with feathers typical of the Bourbon Red variety which thus formed a continuous band around the middle of the body. The difference in the plumage colour of the two varieties was found to depend upon a single pair of autosomal genes, the ratio in theF 2 generation being approximately 1 Bronze to 2F 1 pattern to 1 Bourbon Red. The hybrids resembled the Bronze variety more than the Bourbon Red, particularly in down pattern and adult plumage, but were readily distinguished from both parental varieties. The possible mechanisms that may account for this case are discussed.