Population divergence in sexual ornaments: The white forehead patch of Norwegian pied flycatchers is small and unsexy
Population divergence in sexual ornaments: The white forehead patch of Norwegian pied flycatchers is small and unsexy
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DOI：
10.1111/j.1558-5646.1999.tb04536.x
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发表时间：
1999-08-01
期刊：
影响因子：
3.3
通讯作者：
Saetre, GP
中科院分区：
文献类型：
--
作者：
Dale, S;Slagsvold, T;Saetre, GP
性选择模型表明，种群可能很容易在男性第二性征上发生分化。研究了一个西班牙种群的红腹姬鹬，Ficedulahypoleuca，和一个瑞典种群的密切相关的领姬鹬，F。albicollis的研究表明，雄性的白色前额是一种性选择的特征。我们研究了白色额头补丁的男性蝇（n = 487）在挪威人口超过7年。男性与大额头补丁一般更鲜艳，但补丁的高度与体重，身体大小，或寄生虫负载。在雏鸟期的条件似乎没有影响补丁的高度作为一个成年人。斑块高度略有增加，从第一年到第二年的成年人，但在较高的年龄保持相对恒定。贴片高度与存活率无关。逐年的变化表明，男性谁增加了补丁的高度也增加了体重，这表明前额补丁的表达可能是部分条件依赖性。然而，体重的变化只解释了一小部分男性之间的补丁高度的方差。因此，斑块高度不是雄性质量的良好指标。此外，斑块大小也不相关的男性喂养雏鸟的能力，表明女性不会获得直接的好处，通过选择男性与大斑块。然而，斑块高度可能是一个费舍尔性状，但这需要遗传力，并没有显着的父亲-儿子的相似性斑块高度。在交配采样期间，每个女性访问的男性的比较表明，所选择的男性没有较大的额头补丁比被拒绝的男性。实验操作的补丁高度并不影响男性交配成功。这些结果表明，女性不使用补丁大小作为择偶线索。最后，斑块高度并不能预测雄性争夺巢箱的结果，这表明前额斑块不是性内选择的地位线索。挪威斑姬鹬的前额比西班牙斑姬鹬和瑞典领姬鹬都小。我们认为，这种模式可以解释为缺乏性选择的额头补丁在挪威人口相比，其他人群，补丁显然是性选择。我们讨论了这些人口的分歧，如女性的选择替代第二性征（一般羽毛颜色）和Ficedula flycatchers之间的物种形成可能的原因。
Models of sexual selection suggest that populations may easily diverge in male secondary sexual characters. Studies of a Spanish population of the pied flycatcher, Ficedula hypoleuca, and a Swedish population of the closely related collared flycatcher, F. albicollis, have indicated that the white forehead patch of males is a sexually selected trait. We studied the white forehead patch of male pied flycatchers (n = 487) in a Norwegian population over seven years. Males with large forehead patches were in general more brightly colored, but patch height was not correlated to body mass, body size, or parasite loads. Conditions during the nestling period did not seem to influence patch height as an adult. Patch height increased slightly from the first to the second year as adults, but then remained relatively constant at higher ages. Patch height was not related to survival. Year-to-year changes showed that males who increased in patch height also increased in body mass, suggesting that expression of the forehead patch may be partly condition dependent. However, changes in body mass explained only a small proportion of the variance in patch height between males. Thus, patch height would not be a good indicator of male quality. Furthermore, patch size was also not related to male ability to feed nestlings, indicating that females would not obtain direct benefits by choosing males with large patches. However, patch height could be a Fisher trait, but this requires heritability and there was no significant father-son resemblance in patch height. Comparisons of the males visited by each female during the mate sampling period indicated that chosen males did not have larger forehead patches than rejected males. Experimental manipulation of patch height did not affect male mating success. These results indicate that females do not use patch size as a mate choice cue. Finally, patch height did not predict the outcome of male contests for nestboxes, suggesting that the forehead patch is not an intrasexually selected cue of status. Norwegian pied flycatchers have smaller forehead patches than both Spanish pied flycatchers and Swedish collared flycatchers. We suggest that this pattern may be explained by the lack of sexual selection on the forehead patch in the Norwegian population as compared to the other populations, where the patch is apparently sexually selected. We discuss possible reasons for these population divergences, such as female choice on an alternative secondary sexual character (general plumage color) and speciation among Ficedula flycatchers.