Roles of Sex Steroids in the Crowings with Sexual and Non-Sexual Motivations in Female Japanese Quail, <i>Coturnix Japonica</i>

Abstract

To examine the sex differences in the crowing behavior of the Japanese quail, we investigated the effects of sex steroids on calling behaviors using female birds, and the data were compared with those obtained in our previous study in male birds which was performed using the same experimental procedures as those in the present study. We injected the female quails daily from 11 to 41 days after hatching with testosterone propionate (TP), 5α-dihydrotestosterone (DHT; a non-aromatizable androgen), estradiol benzoate (EB) or vehicle, and examined their calling behaviors in both sexual and non-sexual contexts. In a non-sexual context of the birds being isolated in a recording chamber, androgens, either TP or DHT, induced crowing in place of distress calling while EB simply inhibited distress calling. These effects of sex steroids on the calling behaviors were almost identical to those in the male quails. In a sexual context of the birds being left undisturbed in their home cages, crowing was induced by chronic treatment with TP, but not either DHT or EB, suggesting that both estrogenic and androgenic actions are required to induce the sexually motivated crowing. Although these results were basically the same as those in the male quails, the crowing in the female quails occurred much less frequently compared to that of the male quails. These data suggest that in the Japanese quail, crowing behavior, when it is restricted to sexually motivated one, is quantitatively different between male and female in the responsiveness to sex steroids.