Griggio M, Serra L, Licheri D, Campomori C, Pilastro A
Konrad Lorenz Institute for Ethology, Vienna, Austria.
J Evol Biol. 2009 Apr;22(4):782-92. doi: 10.1111/j.1420-9101.2009.01700.x.
Growing evidence suggests that structural feather colours honestly reflect individual quality or body condition but, contrary to pigment-based colours, it is not clear what mechanism links condition to reflectance in structural feather colours. We experimentally accelerated the moult speed of a group of blue tits (Cyanistes caeruleus) by exposing them to a rapidly decreasing photoperiod and compared the spectral characteristics of their structural feather colours with those of control birds. Blue tits were sexually dimorphic on the UV/blue crown and on the white cheek feathers. Moult speed, however, dramatically reduced brightness and the saturation only on the UV/blue crown feathers, whereas structural white on the cheek feathers was basically unaffected by moult speed. Given that the time available for moulting is usually confined to the period between the end of the breeding season and migration or wintering, UV/blue colours, but not structural white, may convey long-term information about an individual's performance during the previous breeding season. The trade-off between fast moulting and structural colour expression may represent a previously unrecognized selective advantage for early-breeding birds.
越来越多的证据表明，羽毛的结构色能够诚实地反映个体质量或身体状况，但与色素基颜色不同的是，目前尚不清楚是什么机制将身体状况与结构色的反射率联系起来。我们通过将一组蓝山雀（蓝冠山雀）暴露在快速缩短的光照周期下，实验性地加快了它们的换羽速度，并将它们结构羽色的光谱特征与对照鸟类进行了比较。蓝山雀在紫外/蓝色冠羽和白色脸颊羽毛上存在性别二态性。然而，换羽速度仅显著降低了紫外/蓝色冠羽的亮度和饱和度，而脸颊羽毛上的结构白色基本上不受换羽速度的影响。鉴于换羽的可用时间通常局限于繁殖季节结束至迁徙或越冬之间的时间段，紫外/蓝色羽毛颜色而非结构白色，可能传达了有关个体在前一个繁殖季节表现的长期信息。快速换羽与结构色表达之间的权衡可能代表了早繁殖鸟类此前未被认识到的选择优势。
