Female ring doves held under long (16 h per day) or short (8 h per day) photoperiods were treated daily for 15 days with saline, estrogen, or progesterone, alone or in combination. Seven days after the start of hormone therapy females were placed with reproductively active males for 4 h per day for 9 days. There was no difference in egg-laying, courtship, and nest-building by control birds under the two photoregimes.Ovarian follicles remained small in all birds receiving hormone treatment. Oviducts of birds receiving progesterone alone remained small in the short-photoperiod group, but at long photoperiods oviducts became enlarged. Estrogen stimulated oviduct growth at both photoperiods. The combined hormone treatment resulted in considerably greater oviduct development than estrogen alone, and in this case the oviducts of birds under long photoperiod were significantly heavier than those of short-photoperiod birds.Female soliciting and nest-building activity remained low in progesterone-treated females under short photoperiod, but increased rapidly under long photoperiod. Birds treated with estrogen and estrogen and progesterone performed considerable soliciting and nest-building. There was a marked tendency for birds under long-photoperiod conditions to be more active in nest-oriented behaviour. Copulatory behaviour by the female (begging and sexual crouch) occurred infrequently in all hormone-treated birds.
Ovarian activity of female ring doves (Streptopelia risoria) exposed to marginal stimuli from males
