Classification of hybrid crows in quail using artificial neural networks.

In galliforms, calls are strongly determined genetically and no influence of learning has ever been demonstrated. Hybridization is a useful tool for investigating patterns of heritability. The vocal repertoire of the European quail (Coturnix c.

Testosterone levels and the free running rhythm of feeding activity in Japanese quail in darkness.

Castrated male Japanese quail were reared in total darkness for 7 months. In order to mimic changes in concentration of plasma testosterone during sexual development, the birds were implanted on three occasions with increasing numbers of testosterone-filled capsules. The feeding activity of each bird was recorded and concentrations of plasma testosterone were measured before and after capsules were implanted.

Sexual development and free-running period in quail kept in constant darkness.

In Japanese quail (Coturnix coturnix japonica) sexual development may occur in total darkness (DD). Linked to sexual maturation, variations of the rhythm of feeding activity were observed: in DD, the amount of activity increased and the period of the free-running rhythm lengthened. During the first weeks in DD all the quails presented a free-running period less than 24 hr (22.