Phenotypic plasticity in the scaling of avian basal metabolic rate
Phenotypic plasticity in the scaling of avian basal metabolic rate
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DOI：
10.1098/rspb.2005.3415
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发表时间：
2006-04-22
影响因子：
4.7
通讯作者：
Jetz, W
中科院分区：
文献类型：
--
作者：
McKechnie, AE;Freckleton, RP;Jetz, W
许多鸟类表现出短期的，可逆的基础代谢率（BMR）的调整，但表型可塑性鸟类代谢多样性的整体贡献仍然不清楚。现有的BMR数据包括生活在自然环境中的鸟类和在更同质的人工环境中圈养的鸟类的估计值。所有以前的分析种间变异BMR汇总这些数据。我们很高兴。pothesized，表型可塑性是一个重要的贡献者种间变异的鸟类BMR，圈养种群表现出一般差异的BMR相比，野生捕获种群。我们测试了这一假设拟合一般线性模型的BMR数据为231种鸟类，使用广义最小二乘方法来纠正系统发育相关性时，必要的。圈养鸟类的BMR与体重相关的标度指数（0.670）明显低于野生鸟类（0.744）。在控制迁徙趋势和栖息地干旱的情况下，圈养和野生鸟类之间的代谢比例差异仍然存在。我们的研究结果表明，表型可塑性是鸟类种间代谢变异的主要贡献者。鸟类的代谢比例部分取决于环境因素，这一发现为预测比例指数变化的模型（如异速生长级联模型）提供了进一步的支持。
Many birds exhibit short-term, reversible adjustments in basal metabolic rate (BMR), but the overall contribution of phenotypic plasticity to avian metabolic diversity remains unclear. The available BMR data include estimates from birds living in natural environments and captive-raised birds in more homogenous, artificial environments. All previous analyses of interspecific variation in BMR have pooled these data. We hy. pothesized that phenotypic plasticity is an important contributor to interspecific variation in avian BMR, and that captive-raised populations exhibit general differences in BMR compared to wild-caught populations. We tested this hypothesis by fitting general linear models to BMR data for 231 bird species, using the generalized least-squares approach to correct for phylogenetic relatedness when necessary. The scaling exponent relating BMR to body mass in captive-raised birds (0.670) was significantly shallower than in wild-caught birds (0.744). The differences in metabolic scaling between captive-raised and wild-caught birds persisted when migratory tendency and habitat aridity were controlled for. Our results reveal that phenotypic plasticity is a major contributor to avian interspecific metabolic variation. The finding that metabolic scaling in birds is partly determined by environmental factors provides further support for models that predict variation in scaling exponents, such as the allometric cascade model.