Iridescence in the neck feathers of domestic pigeons.
We conducted structural characterizations, reflection measurements, and theoretical simulations on the iridescent green and purple neck feathers of domestic pigeons (Columba livia domestica). We found that both green and purple barbules are composed of an outer keratin cortex layer surrounding a medullary layer. The thickness of the keratin cortex layer shows a distinct difference between green and purple barbules. Green barbules vary colors from green to purple with the observing angle changed from normal to oblique, while purple barbules from purple to green in an opposite way. Both the experimental and theoretical results suggest that structural colors in green and purple neck feathers should originate from the interference in the top keratin cortex layer, while the structure beyond acts as a poor mirror.
Yin
Haiwei
H
Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China.
Shi
Lei
L
Sha
Jing
J
Li
Yizhou
Y
Qin
Youhua
Y
Dong
Biqin
B
Meyer
Serge
S
Liu
Xiaohan
X
Zhao
Li
L
Zi
Jian
J
D000818:Animals; D003116:Color; D003124:Colorimetry / Q000379:methods*; D010856:Columbidae / Q000502:physiology*; D003198:Computer Simulation; D005241:Feathers / Q000737:chemistry* / Q000502:physiology*; D008954:Models, Biological; D008956:Models, Chemical; D009333:Neck / Q000502:physiology