CHANGES IN PLASMA-LEVELS OF LUTEINIZING-HORMONE AND SEX STEROID-HORMONES IN RELATION TO MULTIPLE-BROODEDNESS AND NEST-SITE DENSITY IN MALE STARLINGS
CHANGES IN PLASMA-LEVELS OF LUTEINIZING-HORMONE AND SEX STEROID-HORMONES IN RELATION TO MULTIPLE-BROODEDNESS AND NEST-SITE DENSITY IN MALE STARLINGS
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DOI：
10.1086/physzool.60.2.30158643
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发表时间：
1987-03-01
期刊：
影响因子：
--
通讯作者：
WINGFIELD, JC
中科院分区：
文献类型：
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作者：
BALL, GF;WINGFIELD, JC
研究了两个双窝欧洲椋鸟种群生殖周期中血浆睾酮（T）、孕酮（P）和促黄体生成素（LH）水平的变化。在一个种群中，巢址（巢箱）平均相距6米（密集站点），而在另一个，巢箱平均相距60米（分散站点）。在这两个群体中，血浆T水平高，在两个产卵阶段，当男性配偶守卫和捍卫巢洞。在第一次嵌套尝试期间观察到T的较高循环水平，当所有对拥有箱启动离合器时。此外，血浆T水平较高的男性筑巢在密集的网站相比，男性在分散的网站。只有约30%的这些对开始第二离合器后，成功地提高了第一窝。虽然血浆T水平上升的男性在第二离合器开始，他们显着低于T水平的生产过程中测量的第一离合器。循环水平的LH成为最大的在每个产卵阶段的方式类似的T，但没有变化作为巢址密度的函数。还检查了循环T的变化与T依赖性第二性征，雄性票据颜色的关系。我们发现，票据颜色的季节性变化是敏感的循环水平的T仅略高于基础和远低于男性男性侵略期间观察到的。循环水平的T仅略高于基础和远低于男性男性侵略期间观察到的。循环水平的P是恒定的，从1月至7月，在繁殖前期和繁殖期没有显着变化。这与圈养雄性的研究结果一致。
Changes in plasma levels of testosterone (T), progesterone (P), and luteinizing hormone (LH) were studied over the reproductive cycle in two double-brooded populations of European starlings (Sturnus vulgaris). In one population, nest sites (nest boxes) averaged 6 m apart (dense site), and in the other, nest boxes average 60 m apart (dispersed site). In both populations, plasma levels of T were high during the two egg-laying stages when males were mate guarding and defending nest holes. A higher circulating level of T was observed during the first nesting attempt, when all pairs in possession of a box initiated clutches. Furthermore, plasma levels of T were higher in males nesting at the dense site compared with those in males at the dispersed site. Only about 30% of these pairs initiated second clutches after successfully rearing the first brood. Although plasma levels of T rose in males during the second clutch initiation, they were significantly lower than T levels measured during production of the first clutch. Circulating levels of LH became maximal during each egg-laying stage in a manner similar to those of T but did not vary as a function of nest-site density. Changes in circulating T were also examined in relation to a T-dependent secondary sexual characteristics, male bill color. We found that the seasonal change in bill color is sensitive to circulating levels of T only slightly above basal and much lower than those observed during times of male-male agression. Circulating levels of T only slightly above basal and much lower than those observed during time of male-male agression. Circulating levels of P were constant from January to July, with no significant changes during the prebreeding and breeding periods. This is consistent with results of studies with captive males.