男性的睾酮水平抑制雌鹦鹉产卵繁殖的实验：在虎皮鹦鹉

Male-like testosterone levels inhibit oviposition in a female parrot： A breeding experiment in budgerigars

在一些鸣禽物种的研究表明，雄激素类固醇激素治疗的女性testoste -酮（T）会影响女性的生殖行为和繁殖成功。作为对女性的影响似乎是种属特异性，目前还不清楚是否高T类似的效应发生在非鸣禽物种。在这里，我们研究了T对虎皮鹦鹉，雌性的生殖行为和产卵的影响虎皮鹦鹉，小鹦鹉物种与一夫一妻制父母行为的明显的性别差异。我们的实验增加T浓度男性喜欢T-治疗的女性相比对照组水平，我们允许女性繁殖。我们没有发现显著的治疗效果在延迟进入巢箱但治疗显著干扰产卵。我们的研究结果表明，T-治疗的女性的七倍，不可能产生一个离合器的女性比控制。我们发现，T处理对产卵有很强的抑制作用，我们的研究结果表明，雌鹦鹉患有男性喜欢血浆T水平的健身费用。因此，它是可能的，也是非鸣禽物种，在男性的睾酮水平更高的选择是通过选择相关的响应对健身成本而言，再现女性的约束。评估是否的确是这种情况需要进一步的工作，结合不同的方法对男性和女性的睾酮水平61 [现有生态演化的研究（4）：586-595，2015 ]。

Studies in several songbird species have shown that treating females with the androgenic steroid hormone testoste- rone （T） can negatively affect female reproductive behaviors and breeding success. As the effects of T on females appear to be species-specific, it is not clear if similar effects of high T occur in non-songbird species. Here, we studied the effects of T supplementation on female reproductive behavior and oviposition in the budgerigar, Melopsittacus undulatus, a small monogamous parrot species with distinct sex differences in parental behavior. We experimentally increased T concentrations to male-like levels in T-treated females compared to controls and we allowed females to breed. We found no significant effects of treatment on the latency to enter the nestbox but T treatment significantly interfered with oviposition. Our results show that T-treated females were seven times less likely to produce a clutch than control females. As we found that T treatment had a strong inhibitory effect on oviposition, our results indicate that female budgerigars suffer fitness costs from male-like plasma T levels. Therefore, it may be possible that, also in non-songbird species, selection for higher T levels in males is constrained by a correlated response to selection which imposes fitness costs on females in terms of reproduction. Evaluating whether or not this is indeed the case requires further work combining different approaches to the study of the evolution of male and female testosterone levels [Current Zoology 61 （4）： 586-595, 2015].