Guide to North American Birds
Credits: All illustrations © David Allen Sibley. All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman © 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved. Bird call audio © Lang Elliott & Associates. Photography sourced in part from VIREO, the worldwide bird photography collection of the Academy of Natural Sciences of Drexel University.