Effects of Sunlight Exposure on Carotenoid-Based and Structural Coloration of the Blue-Tailed Bee-Eater

[摘要] Abstract. After a bird's molt is complete, the coloration of its plumage may be altered by external factors such as soiling. We tested how exposure to sunlight affects plumage coloration derived from carotenoid pigments and feather nanostructure. We studied these changes in the Blue-tailed Bee-eater (Merops philippinus) because that species combines yellow chin feathers (colored by carotenoid pigments), green back feathers (colored by a combination of carotenoid pigments and feather nanostructure), and turquoise-blue rump feathers (colored by feather nanostructure). We measured reflectance of feather samples and then exposed them to sunlight in boxes that allowed penetration of both UV and visible wavelengths of light. After exposure to sunlight, reflectance spectrometry revealed that all three regions became less colorful. According to models of avian sight, chromatic aspects of color change were too small to be perceived in the majority of individuals. In contrast, the reduction in brightness after expo...

[学科分类] 动物科学

[关键词] bee-eaters;color bleaching;Coraciiformes;keratin;Merops philippinus;UV radiation