Bird-frog

tapirage: "Macaws and other parrots supplied most of the plumage, but that of other species — Muscovy ducks, flamingos, egrets and the petite paradise tanager — was also prized. Some colors were produced artificially in a process known as tapirage. Birds with, say, green and blue feathers were plucked and then rubbed with frog secretions; the feathers would then grow back in an unnatural yellow-orange hue." —NYT