EVOLUTIONARY DETERMINANTS OF CLUTCH SIZE IN CAVITY-NESTING BIRDS - NEST PREDATION OR LIMITED BREEDING OPPORTUNITIES
EVOLUTIONARY DETERMINANTS OF CLUTCH SIZE IN CAVITY-NESTING BIRDS - NEST PREDATION OR LIMITED BREEDING OPPORTUNITIES
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DOI：
10.1086/285582
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发表时间：
1993-12-01
影响因子：
2.9
通讯作者：
MARTIN, TE
中科院分区：
文献类型：
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作者：
MARTIN, TE
近半个世纪以来，大型洞巢鸟类一直被认为是低巢捕食后果的经典例子。我的研究表明，巢穴捕食量的减少不能解释洞巢鸟类窝窝大小的原因。相反，北美和欧洲洞穴筑巢物种的窝巢大小与挖掘洞穴的倾向更密切相关。挖掘的倾向由物种的头骨和喙的形态决定。与挖掘新洞的物种相比，挖掘形态较弱的物种对现有洞穴的依赖程度更高，每年有更大的离群量和更多的幼虫。这些结果不能用挖掘的能源成本来解释。成人中非生殖死亡的可能影响无法评估。结果支持了一个新的假设，即依赖现有洞穴的物种的筑巢地点越有限，有利于更大的繁殖努力。
Large clutch sizes of cavity-nesting birds have been considered a classic example of the consequences of low nest predation for almost half a century. I show that reduced nest predation cannot explain large clutch sizes in cavity-nesting birds. Instead, clutch sizes of cavity-nesting species in North America and Europe are more closely related to the propensity to excavate nest holes. Propensity to excavate is determined by skull and bill morphology of species. Species with weaker excavating morphology depend on existing holes more and have larger clutches and more broods per year than species that excavate new holes. These results cannot be explained by energy costs of excavation. Possible effects of nonreproductive mortality among adults cannot be evaluated. The results support a new hypothesis that the more limited availability of nest sites for species that depend on existing holes favors greater reproductive effort.