Sexual selection in the barn swallow Hirundo rustica .4. Aerodynamic adaptations
Sexual selection in the barn swallow Hirundo rustica .4. Aerodynamic adaptations
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DOI：
10.1046/j.1420-9101.1995.8060671.x
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发表时间：
1995-11-01
影响因子：
2.1
通讯作者：
Saino, N
中科院分区：
文献类型：
--
作者：
Moller, AP;deLope, F;Saino, N
第二性征被认为是昂贵的生产和维护，这将选择形态修改，减少这种成本的幅度。在这里，我们测试是否羽毛装饰，性夸张的最外层尾部羽毛的男性谷仓燕子Hirundo rustica，一个特性，目前受到定向女性配偶偏好，和其他方面的形态用于飞行已被修改，以增加空气动力学性能。这是通过比较种群内的性别，种群内尾巴长度不同的个体，以及欧洲不同地区的种群来完成的。与雌性相比，雄性家燕通过装饰羽毛的形态改变减少了细长尾羽的阻力。最外层尾羽的形态特征与种群内雄性和雌性的尾长无关。与雌性相比，雄性的翅膀和尾巴形态（中央尾羽和翅膀的长度、翼展、翼面积、翼载荷和长宽比）发生了变化。长尾巴的家燕有形态上的尾巴和翅膀修改，减少了大装饰品的成本，在种群中也看到了类似的修改。因此，通过降低成本的形态学改变，夸大第二性征的成本降低了。可靠的信号理论的假设，即信号应该是昂贵的，但更多的是低比高质量的个人，没有违反，因为长尾男性家燕有最大的成本降低形态特征。
Secondary sexual characters are assumed to be costly to produce and maintain, and this will select for morphological modifications that reduce the magnitude of such costs. Here we test whether a feather ornament, the sexually exaggerated outermost tail feathers of male barn swallows Hirundo rustica, a trait currently subject to a directional female mate preference, and other aspects of the morphology used for flight have been modified to increase aerodynamic performance. This was done by making comparisons among sexes within populations, among individuals varying in tail length within populations, and among populations from different parts of Europe. Male barn swallows experienced reduced drag from their elongated tail feathers by morphological modifications of the ornamental feathers as compared to females. Morphological features of the outermost tail feathers were unrelated to tail length in both males and females within populations. Wing and tail morphology (length of central tail feathers and wings, wing span, wing area, wing loading, and aspect ratio) was modified in males compared to females. Barn swallows with long tails had morphological tail and wing modifications that reduced the cost of a large ornament, and similar modifications were seen among populations. The costs of the exaggerated secondary sexual character were therefore reduced by the presence of cost-reducing morphological modifications. The assumptions of reliable signalling theory, that signals should be costly, but more so to low than to high quality individuals, were not violated because long-tailed male barn swallows had the largest cost-reducing morphological characters.