Feathersbeta-KeratinsPorcupinesMicrotomyBirdsOptical PhenomenaPigmentationForeign-Body MigrationFlight, AnimalMelaninsAnimal StructuresFinchesColorEndoleakModels, AnatomicBlood Vessel ProsthesisMicroscopy, Electron, ScanningMaterials TestingPigments, BiologicalNanostructuresProsthesis DesignKeratinsMorphogenesisFourier AnalysisBlood Vessel Prosthesis ImplantationEpidermisAortographyMicroscopy, ImmunoelectronBiomechanical PhenomenaChickensStentsStaining and Labeling