Wingfield J C, Monk D
Department of Zoology, University of Washington, Seattle 98195.
Horm Behav. 1994 Jun;28(2):146-54. doi: 10.1006/hbeh.1994.1012.
Previous studies on several species have shown that behavior of female vertebrates given estradiol implants to maintain sexual receptivity resulted in elevated levels of testosterone in males and even delayed termination of breeding in their otherwise untreated mates. However, the efficacy of such treatment in the non-breeding season was unclear. In this study, female song sparrows, Melospiza melodia morphna, given implants of estradiol in autumn showed elevated sexual behavior--especially "chitters," a loud, female-specific vocalization used mostly during the breeding season. Males in autumn appeared to ignore the sexual behavior of these females, showed no difference in response to simulated territorial intrusion, and had basal circulating levels of testosterone when compared with males tested in an area of control females. However, by late winter (February) males in the area where females were treated with estradiol had elevated levels of testosterone compared to control males and those of both groups sampled in autumn. These data indicate that sexual behavior of females, experimentally induced by estradiol implants, failed to increase sexual and territorial behavior in males during the autumn. On the other hand, reproductive behavior of females did appear to accelerate the vernal increase in testosterone concentrations in blood of males.
此前对多个物种的研究表明，给雌性脊椎动物植入雌二醇以维持性接受能力，会导致雄性体内睾酮水平升高，甚至会使未接受治疗的配偶的繁殖期延长。然而，这种治疗在非繁殖季节的效果尚不清楚。在本研究中，秋季接受雌二醇植入的雌性歌带鹀（Melospiza melodia morphna）表现出性行为增加，尤其是“啁啾声”，这是一种响亮的、雌性特有的叫声，主要在繁殖季节发出。秋季的雄性似乎忽略了这些雌性的性行为，对模拟领地入侵的反应没有差异，与在对照雌性区域测试的雄性相比，其睾酮的基础循环水平也没有变化。然而，到了冬末（2月），与对照雄性以及秋季采样的两组雄性相比，接受雌二醇治疗的雌性所在区域的雄性睾酮水平升高。这些数据表明，秋季通过植入雌二醇实验诱导的雌性性行为，未能增加雄性的性行为和领地行为。另一方面，雌性的生殖行为似乎确实加速了雄性血液中睾酮浓度的春季升高。
