In birds almost the entire skin is covered by plumage. Therefore concomitantly with the evolution of feathers a system of coloration had to be developed. From the reptilian heritage keratin either uncoloured or with diffuse pigments, melanosomes and air-filled cavities have been provided. By means of sophisticated interactions of this basal equipment the most luxurious costumes in the animal kingdom have evolved. Colouration and the kind of plumage presented is closely related to age (natural down, juvenile or adult plumage), sex (nuptial or hen’s plumage) or behaviour, e.g. camouflage (with seasonal changes in many species), mating behaviour, aggression in territorial defense.
Keywords
- Structural Colour
- Interference Colour
- Melanin Granule
- Preen Gland
- Diffuse Pigment
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.