Two illustrations from the book Colouration in Animals and Plants by Alfred Tylor, 1886 Illustration by S. T. Dadd in the book Wild Traits in Tame Animals by Louis Robinson, 1897Three illustrations from the book Marvels of Animal Life by Charles Frederick Holder, 1885Painting by John James Audubon from the Field Museum of Natural History Bulletin, Volume 47, 1976
