Effects of castration on postnatal differentiation in the Japanese quail (Coturnix coturnix japonica)

Male and female quail were neutered at 1 day or 1–6 wks after hatching, and Ss were implanted with silastic tubing containing testosterone at 2 mo. In a test after another 3 wks, male-type sexual behavior was more common in females neutered at or before 2 wks than afterward, whereas a time effect was not found among males. Findings indicate that sexual differentiation in quail results from demasculinization of females by ovarian secretions and that this is a continuous process that is completed at different stages of development for different androgen-dependent structures.