A Photographic Companion to the Identification Guide to North American Birds, Part 1. \nThis photo guide accompanies Pyle Guide Part 1, and is extremely helpful as a visual aid in identification of molt limits and plumage patterns. Click above for the PDF download from IBP's publication database.\nFroehlich, D. 2003. Ageing North American landbirds by molt limits and plumage criteria. Slate Creek Press, Bolinas, California.\nPhoto courtesy of Tony Oppersdorf, 2011.