title: Structural origin of the colored reflections from the black-billed magpie feathers.
abstract: The structural origin of the weak iridescence on some of the dark feathers of the black-billed magpie, Pica pica (Corvidae), is found in the structure of the ribbon-shaped barbules. The cortex of these barbules contains cylindrical holes distributed as the nodes of an hexagonal lattice in the hard layer cross section. The cortex optical properties are described starting from a photonic-crystal film theory. The yellowish-green coloration of the bird's tail can be explained by the appearance of a reflection band related to the photonic-crystal lowest-lying gap. The bluish reflections from the wings are produced by a more complicated mechanism, involving the presence of a cortex second gap."
authors.affiliation: Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium. jean-pol.vigneron@fundp.ac.be
authors.forename: Jean Pol
authors.initials: JP
authors.lastname: Vigneron
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Colomer
authors.forename: Marie
authors.initials: M
authors.lastname: Rassart
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Ingram
authors.forename: Virginie
authors.initials: V
authors.lastname: Lousse
mesh_terms: D000818:Animals; D001717:Birds / Q000033:anatomy & histology* / Q000502:physiology*; D003124:Colorimetry / Q000379:methods*; D003198:Computer Simulation; D005241:Feathers / Q000502:physiology* / Q000648:ultrastructure*; D008027:Light; D008954:Models, Biological; D012542:Scattering, Radiation