海南昌江家燕(Hirundo rustica)种群的卵色及其窝内窝间变异

Egg color and its intra- and inter-clutch variation of a barn swallow( Hirundo rustica )population in Changjiang,Hainan,China

量化鸟类的卵色及其窝内、窝间变异,对于理解鸟类卵色的进化及其适应性具有重要意义。具有较小的卵色窝内变异和较大的窝间变异,有利于寄主反寄生行为对策的进化。最近的研究表明,除了同种寄生,家燕(Hirundo rustica)同时也是杜鹃(Cuculus spp.)的重要寄主之一。本研究利用光纤光谱仪,对海南昌江家燕种群的卵色进行量化分析。结果表明:家燕卵背景色的反射光谱明显高于斑点色,斑点色在长波光部分有较高的波峰和波谷,表明在黄色和红色光上具有较高的色彩饱和度;虽然肉眼看到的家燕卵的背景和斑点颜色截然不同,但基于鸟类视觉模型的统计分析表明,两者的色调的可见光部分(RGB)并无显著差异,而在人眼无法探测的紫外光(UV)部分及色度和亮度上均存在极显著差异;家燕卵色的窝内、窝间变异分析结果表明,家燕卵的背景色和斑点的窝内变异不显著;而在窝间变异上,UV、色度和亮度均无显著差异,但色调RGB具有显著差异,斑点的窝间变异大于背景色。本研究是家燕卵色定量化分析的首次报道。

Quantization of egg color and intra and interclutch variation plays an important role in understanding the evolution and adaptability of bird egg coloration. Host species utilized by cuckoos have less variation in egg appearance within a clutch and more variation between individuals while species with no history of cuckoo parasitism present opposite properties. In this study, fiber spectrophotometer was used to quantitatively analyze the egg color of a barn swallow （Hirundo rustica） population in Changjiang, Hainan, China. Egg reflectance of ground color in barn swallows was higher than that of the pattern color. The egg pattern reflectance had higher wave crest and lower wave vale, which indicated that egg pattern had bigger color saturation than ground color. Although ground and pattern colors look obviously different by human eyes, avian visual modeling showed that their difference in hue （red, green and bluesensitive cones, RGB） was not statistically significant. However, the chroma, brilliance and ultraviolet （UV） of barn swallow eggs were highly different between ground color and pattern. The intraclutch variation between ground color and pattern was not statistically different. As to the interclutch variation, the hue RGB of pattern was higher than that of the ground color while the UV, chroma and brilliance were not statistically different. To our knowledge, this is the first quantitative study of barn swallow egg coloration.