Aromatase inhibition reduces specifically one display of the ring dove courtship behavior

The courtship behavior of the male ring dove (Streptopelia risoria) combines aggressive displays (chasing, bowing) and nest-oriented displays (nest soliciting). Aggressive displays depend on circulating testosterone, whereas nest soliciting is estrogen-dependent and appears to depend on the aromatization of androgen into estrogen within the brain. The present work tested the hypothesis that aromatase specifically modulates the nest soliciting display in intact male ring doves. Males were tested for courtship behavior with receptive females before and after being implanted with micro-osmotic pumps containing Fadrozole, a nonsteroidal aromatase inhibitor, or saline. Fadrozole at the higher dose reduced estrogen-dependent nest soliciting but did not affect androgen-dependent chasing and bowing. These results support the hypothesis that aromatase modulates nest soliciting in male ring doves, and provide further evidence for separate hormonal control of different courtship displays in this species. (C) 2001 Academic Press