Male traits and female choice in Java Sparrows: preference for large body size
Male traits and female choice in Java Sparrows: preference for large body size
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DOI：
10.2326/osj.10.73
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发表时间：
2011-06-01
影响因子：
0.6
通讯作者：
Hasegawa, Toshikazu
中科院分区：
文献类型：
--
作者：
Hasegawa, Ai;Soma, Masayo;Hasegawa, Toshikazu
雌雀是雌性交配偏好实验研究的重要模式物种，但研究只集中在该家族的两个物种，即斑马雀Taeniopygia guttata和孟加拉雀Lonchura striata var。而我们对其他与之密切相关的物种知之甚少。因此，我们调查的Java麻雀Padda oryzivora，这也属于家庭Estrildidae的性二型和女性的选择，开辟了比较研究的潜力，更好地了解这个家庭的性选择。首先，我们采取了8个形态特征的测量6名男性和6名女性爪哇麻雀：自然翅长，最大翅长，跗长，尾长，暴露的culmen长度，法案宽度，法案深度和身体质量。我们定量证实，爪哇麻雀显示两性异形的法案深度，男性比女性更深的法案。其次，我们通过分析雄性求偶歌的声学结构和句法结构来研究个体差异。在收集了雄性形态和歌曲相关特征的数据后，我们进行了双向选择测试，询问哪种雄性特征预测雌性爪哇麻雀更喜欢哪种雄性。在选择试验中，我们将一个装有雌性的笼子放在两个笼子之间，每个笼子里有一个雄性，并通过点采样每30秒记录一次雌性的位置。我们进行了逐步回归分析，以评估女性花在每个男性和男性的形态和歌曲相关的特征面前的时间之间的关系。结果表明，雌性对大体型的偏好是基于大体型，这可能是雄性质量的一个很好的指标。然而，没有偏好观察到歌曲相关的性状或性二形法案深度。也许两性在嘴的大小上的差异是雄性与雄性竞争的进化结果。
Estrildine finches are important model species in experimental studies on female mating preferences, but research has focused on only two species from this family, namely, the Zebra Finch Taeniopygia guttata and the Bengalese Finch Lonchura striata var. domestica, and we know comparatively little about other closely related species. Therefore, we investigated sexual dimorphism and female choice in the Java Sparrow Padda oryzivora, which also belongs to the family Estrildidae, to open up the potential for comparative research and to better understand sexual selection in this family. First, we took measurements of eight morphological traits of six male and six female Java Sparrows: natural wing length, maximum wing length, tarsus length, tail length, exposed culmen length, bill width, bill depth and body mass. We quantitatively confirmed that Java Sparrows show sexual dimorphism in bill depth, with males having deeper bills than females. Second, we examined individual variation in male courtship songs by analyzing their acoustic and syntactical structure. After collecting data on male morphological and song-related traits, we conducted two-way choice tests to ask which kinds of male traits predicted which males were preferred by female Java Sparrows. In the choice tests, we put a cage with a female in between two cages each containing one male and recorded the position of the female every 30 seconds by point sampling. We performed a stepwise regression analysis to assess the relationship between the time females spent in front of each male and male morphological and song-related traits. The results indicated that females base their preference upon large body size, which is likely to act as a good indicator of male quality. However, no preference was observed for song-related traits or sexually dimorphic bill depth. Perhaps the sexual dimorphism in bill size is instead the evolutionary outcome of male-male competition.