麻雀两性羽色的比较

Is Tree Sparrow Sexual Dichromatic in Plumage Coloration?

鸟类对色彩有较强的区分能力。基于鸟类视觉模型的研究发现,在人类看来类似的羽色,在鸟类眼中存在差别。本研究通过量化麻雀(Passer montanus saturatus)羽毛的反射光谱以及身体量度和喉部、耳羽的黑色斑块面积,比较其在雌鸟和雄鸟之间的差异。研究发现,麻雀雌鸟和雄鸟的身体量度、喉部和耳羽的斑块面积在繁殖季和非繁殖季均无显著差异。基于鸟类的视觉模型,麻雀头顶、喉部、耳羽、腰部的羽色,在雌鸟和雄鸟间无明显分化。基于上述结果,我们认为麻雀的雌鸟和雄鸟在外形上没有表现出性二型。

Color discriminability in birds is enhanced both by tetrachromacy and colored oil droplets. Most sexually monochromatic passerine birds, from a human visual perspective, were actually sexually dichromatic from an avian visual perspective, based on comparisons of plumage reflectance data using a visual model. In this study, we compared the plumage reflectance, body measurements and patch sizes between male and female Tree Sparrow（Passer montanus saturatus）. Totally, 45 individuals（18 males and 27 females） captured in 2014 and fed in the campus of Beijing Normal University were used in this study. In the non-breeding season（15 Jan. 2017） and breeding season（17 Apr. 2017）, body size, area of black throat and ear patch, and reflectance spectrums of crown, throat, ear covert and rump were measured from 29 birds each time. Based on multivariate analysis of variance of body measurements（Table 1） and independent t-test of patch sizes（Fig. 1）, we found there is no obvious difference between males and females, in both breeding season and non-breeding season. From an avian visual perspective, Tree Sparrow is a sexually monochromatic bird through analysis of bird vision model that based on the plumage reflectance data（Table 2 3, Fig. 2）. Summarily, there is no sexual dichromatic in Tree Sparrow in our analysis. We wish the above results can provide basic information for the evolution of sexual dichromatism in Old World Sparrows.