Shawkey Matthew D, Estes Anne M, Siefferman Lynn M, Hill Geoffrey E
Department of Biological Sciences, Auburn University, 331 Funchess Hall, Auburn, AL 36849, USA.
Proc Biol Sci. 2003 Jul 22;270(1523):1455-60. doi: 10.1098/rspb.2003.2390.
Evidence suggests that structural plumage colour can be an honest signal of individual quality, but the mechanisms responsible for the variation in expression of structural coloration within a species have not been identified. We used full-spectrum spectrometry and transmission electron microscopy to investigate the effect of variation in the nanostructure of the spongy layer on expression of structural ultraviolet (UV)-blue coloration in eastern bluebird (Sialia sialis) feathers. Fourier analysis revealed that feather nanostructure was highly organized but did not accurately predict variation in hue. Within the spongy layer of feather barbs, the number of circular keratin rods significantly predicted UV-violet chroma, whereas the standard error of the diameter of these rods significantly predicted spectral saturation. These observations show that the precision of nanostructural arrangement determines some colour variation in feathers.
有证据表明，羽毛的结构颜色可以作为个体品质的真实信号，但尚未确定导致物种内部结构色表达变化的机制。我们使用全光谱光谱法和透射电子显微镜来研究海绵层纳米结构的变化对东部蓝鸲（Sialia sialis）羽毛结构紫外（UV）-蓝色着色表达的影响。傅里叶分析表明，羽毛纳米结构高度有序，但不能准确预测色调变化。在羽枝的海绵层内，圆形角蛋白棒的数量显著预测了紫外-紫色色度，而这些棒直径的标准误差显著预测了光谱饱和度。这些观察结果表明，纳米结构排列的精度决定了羽毛的一些颜色变化。
