On showy dwarfs and sober giants: body size as a constraint for the evolution of bird plumage colouration
On showy dwarfs and sober giants: body size as a constraint for the evolution of bird plumage colouration
复制标题
DOI：
10.3161/000164513x670007
复制
发表时间：
2013-06-01
影响因子：
0.7
通讯作者：
Carrascal, Luis M.
中科院分区：
文献类型：
--
作者：
Galvan, Ismael;Negro, Juan J.;Carrascal, Luis M.
鸟类羽毛颜色的演变可以用广泛的选择压力来解释，包括防御和广告需求。然而，羽毛颜色和体型之间的关系从未被详细研究过。在这里，我们假设身体大小代表羽毛颜色异质性进化的限制，因为身体羽毛的相对数量被认为随着身体大小的减少而增加，并且在基于胡萝卜素的着色的情况下，因为循环中的胡萝卜素的浓度随着身体大小的增加而减少。在这里，我们在一个包括测量雄性羽毛颜色异质性的数据集上测试这些预测，该数据集使用了来自55个鸟类科的111个物种的鸟类视觉感知模型。对92种鸟类的羽毛数量和身体大小之间的相关性的测试表明，这些变量之间存在正相关，而不是之前所说的负相关。正如预测的那样，在控制了系统发育、性别二色性、颜色视觉类型和栖息地的影响后，羽毛颜色异质性(以颜色广度衡量)与体型呈负相关，我们认为类胡萝卜素水平显示的负异速生长可能是导致这种负相关的机制。生活在开阔环境中的物种的羽毛颜色异质性低于植被较多的物种。我们的结果通过与体型大小的关系为鸟类颜色异质性的种间差异提供了一般的解释。
The evolution of bird plumage colouration may be explained by a wide range of selective pressures, including both defensive and advertising needs. However, the relationship between plumage colouration and body size has never been investigated in detail. Here we hypothesize that body size represents a constraint for the evolution of plumage colour heterogeneity because the relative number of body feathers was suggested to increase as body size decreases, and in the case of carotenoid-based colourations because the concentrations of circulating carotenoids decrease with increasing body size. Here we test these predictions on a dataset comprising measurements of male plumage colour heterogeneity using a model of avian visual perception in 111 species from 55 families of birds. A test of the correlation between number of feathers and body size in 92 species of birds showed a positive, instead of negative as previously suggested, association between these variables. As predicted, there was a negative relationship between plumage colour heterogeneity (measured as colour span, a measure of the contrast among colour patches) and body size after controlling for the effects of phylogeny, sexual dichromatism, colour vision type and habitat, and we suggest that the negative allometry shown by carotenoid levels may be the mechanism responsible for this negative relationship. Plumage colour heterogeneity was lower in species inhabiting open environments than in more vegetated habitats. Our results offer a general explanation for interspecific variation in bird colour heterogeneity through an association with body size.