Bebbington Kat, Kingma Sjouke A, Fairfield Eleanor A, Spurgin Lewis G, Komdeur Jan, Richardson David S
School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, 9700CC, Groningen, The Netherlands.
Behav Ecol. 2017 Mar-Apr;28(2):407-418. doi: 10.1093/beheco/arw167. Epub 2016 Dec 19.
Many studies have assessed the costs of sibling rivalry in systems where offspring always have competitors, but conclusions about sibling rivalry in these species are restricted to interpreting the cost of changes in the relative level of competition and are often complicated by the expression of potentially costly rivalry related traits. Additionally, the majority of studies focus on early-life sibling rivalry, but the costs of competition can also affect later-life performance. We test a suite of hypothesized immediate (early-life body mass, telomere length, and survival) and delayed (adult reproductive potential and lifespan) costs of sibling rivalry for offspring of differing competitive ability in Seychelles warblers, where most offspring are raised singly and hence competitor success can be compared to a competition-free scenario. Compared to those raised alone, all competing nestlings had lower body mass and weaker competitors experienced reduced survival. However, the stronger competitors appeared to have longer adult breeding tenures and lifespan than those raised alone. We propose that comparisons with competition-free groups, as well as detailed fitness measures across entire lifetimes, are needed to understand the evolution of sibling rivalry and thus individual reproductive strategy in wild systems.
许多研究评估了在后代始终存在竞争者的系统中同胞竞争的成本，但关于这些物种中同胞竞争的结论仅限于解释竞争相对水平变化的成本，而且往往因潜在代价高昂的竞争相关性状的表达而变得复杂。此外，大多数研究关注的是早期的同胞竞争，但竞争成本也会影响后期的表现。我们测试了一系列关于塞舌尔莺不同竞争能力后代同胞竞争的假设即时成本（早期体重、端粒长度和存活率）和延迟成本（成年繁殖潜力和寿命），在塞舌尔莺中，大多数后代是单独饲养的，因此可以将竞争者的成功与无竞争的情况进行比较。与单独饲养的雏鸟相比，所有参与竞争的雏鸟体重都较低，较弱的竞争者存活率降低。然而，较强的竞争者似乎比单独饲养的竞争者有更长的成年繁殖期和寿命。我们认为，需要与无竞争组进行比较，以及对整个生命周期的详细适合度测量，以了解同胞竞争的进化，从而了解野生系统中的个体繁殖策略。
