Sex biased natal dispersal in a closed, saturated population of Seychelles warblers Acrocephalus sechellensis
Sex biased natal dispersal in a closed, saturated population of Seychelles warblers Acrocephalus sechellensis
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DOI：
10.1111/j.0908-8857.2008.04124.x
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发表时间：
2008-01-01
影响因子：
1.7
通讯作者：
Komdeur, Jan
中科院分区：
文献类型：
--
作者：
Eikenaar, Cas;Richardson, David S.;Komdeur, Jan
个体从纳塔尔地到第一次繁殖地以及繁殖地之间的距离，对种群的动态和遗传结构有重要影响。几乎所有以前的研究扩散的问题，因为研究领域只包括一部分人口，移民可能已经混淆了死亡率。因此，远距离扩散者可能被忽视，扩散数据偏向于短距离。通过研究一个几乎封闭的人口塞舌尔莺Acrocephalus sechellensis，我们得到了几乎无偏的结果，在几个方面的扩散。在大多数其他鸟类物种，纳塔尔扩散距离是女性偏见的塞舌尔莺。雌性后代也比雄性后代更远离纳塔尔地寻找繁殖空缺。纳塔尔扩散距离的性别偏见，但是，取决于当地的繁殖密度。在雄性中，扩散距离随着与纳塔尔区域接壤的区域数量的增加而减小，而在雌性中，扩散距离不随局部密度而变化。繁殖者的传播是罕见的，与大多数物种不同，性别之间的距离没有差异。我们认为，我们的研究结果有利于这样一个想法，即纳塔尔传播距离在塞舌尔莺的性别偏见是由于避免近亲繁殖，而不是资源的竞争或交配内的竞争。
The distances that individuals disperse, from their natal site to the site of first breeding and between breeding sites, have important consequences for the dynamics and genetic structure of a population. Nearly all previous studies on dispersal have the problem that, because the study area encompassed only a part of the population, emigration may have been confounded with mortality. As a result long-distance dispersers may have been overlooked and dispersal data biased towards short distances. By studying a virtually closed population of Seychelles warblers Acrocephalus sechellensis we obtained almost unbiased results on several aspects of dispersal. As in the majority of other avian species, natal dispersal distance was female biased in the Seychelles warbler. Female offspring also forayed further from the natal territory in search of breeding vacancies than male offspring. The sex bias in natal dispersal distance did, however, depend on local breeding density. In males, dispersal distance decreased as the number of territories bordering the natal territory increased, while in females, dispersal distance did not vary with local density. Dispersal by breeders was rare and, unlike in most species, distances did not differ between the sexes. We argue that our results favour the idea that the sex bias in natal dispersal distance in the Seychelles warbler is due to inbreeding avoidance and not resource competition or intrasexual competition for mates.