Domestication changes in Japanese quail (Coturnix japonica): a review

Domestic quail (Coturnix japonica domestica) is a domesticated gallinaceous bird that originated in East Asia with ancestor the wild Japanese quail (Coturnix japonica). Subsequently, to domestication, quail have undergone a number of morphological, ethological and productive changes that make them quite different from those of their wild ancestors. These reflect greater intraspecific differences than even in the differences between species in the genus Coturnix. Unlike the wild quail, a variety of other plumage colours are seen in the domestic quail, the most popular being variations of golden, tuxedo, extended brown and recessive white. The average live weight of the wild Japanese quail varies within 85-110 g, whereas the domestic quail are about 45% to more than 250% heavier, depending on their productive type. Major differences are visible in the migratory, sexual, nesting and brooding behaviour, and other ethological reactions such as vocalisation, mating calls, aggression and fighting. A number of productive parameters have been affected by domestication. Wild Japanese quail lay about 5-14 eggs per clutch, with 2-3 broods per year. Domestic quail could lay more than 250 eggs per year with average egg weight increase of 20% in egg production to 100% in meat production compared to their ancestors. This review summarises how domestication and human impact affect a number of features, significantly altering the Japanese quail. The aim is to emphasise the changes that occurred during the domestication of Japanese quail, supporting the proposal of using the term 'domestic quail' (Coturnix japonica domestica).