Niche variation and the maintenance of variation in body size in a burying beetle
Niche variation and the maintenance of variation in body size in a burying beetle
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DOI：
10.1111/een.12275
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发表时间：
2016-02-01
影响因子：
2.2
通讯作者：
Royle, Nick J.
中科院分区：
文献类型：
--
作者：
Hopwood, Paul E.;Moore, Allen J.;Royle, Nick J.
1.在埋葬甲虫（Nicrophorinae），身体大小是已知的，既提供了繁殖力优势（女性）和成功的资源防御（男性和女性）。尽管如此，在自然种群中观察到相当大的体型变化。一个可能的解释是，这种变化的维持，即使在种内和种间的资源竞争，个体可能会根据身体大小的不同大小的育种资源进行分类。我们测试了预测，“越大越好”，在野外和实验室中，通过实验操纵可用的繁殖资源大小（小鼠尸体）和竞争对手的身体大小的组合在Nicrophorus vespilloides（Herbst 1783）。在该领域，大的女性甲虫遗弃小尸体，没有繁殖，往往比他们更大的尸体，但小女性使用尸体不加区别地与大小。在实验室中，大型甲虫在较大的尸体上比小型甲虫养育更多的后代，但在较小的尸体上，小型甲虫比大型甲虫具有繁殖优势。子代体尺与胴体体尺协变，与亲本体尺无关。目前的综合结果表明，育种资源价值取决于个人的身体大小，身体大小的变化是环境引起的：保持可用的胴体大小的差异。这产生了一种机制，通过这种机制，个体专业化导致这些甲虫通过身体大小增加生态位变化。
1. In burying beetles (Nicrophorinae), body size is known to provide both a fecundity advantage (in females) and successful resource defence (in males and females). Despite this, considerable variation in body sizes is observed in natural populations.2. A possible explanation for the maintenance of this variation, even with intra- and inter-specific resource competition, is that individuals might assort according to body size on different-sized breeding resources.3. We tested prediction that 'bigger is always better', in the wild and in the laboratory, by experimentally manipulating combinations of available breeding-resource size (mouse carcasses) and competitor's body size in Nicrophorus vespilloides (Herbst 1783).4. In the field, large female beetles deserted small carcasses, without breeding, more often than they did larger carcasses, but small females used carcasses indiscriminately with respect to size. In the laboratory, large beetles reared larger broods (with more offspring) on larger carcasses than small beetles, but on small carcasses small beetles had a reproductive advantage over large ones. Offspring size covaried with carcass size independently of parental body size.5. The present combined results suggest breeding resource value depends on an individual's body size, and variation in body size is environmentally induced: maintained by differences in available carcass sizes. This produces amechanism by which individual specialisation leads to an increase in niche variation via body size in these beetles.