National Audubon Society Sibley Guide to Birds
Here's what other sites are saying:
The National Audubon Society's comprehensive and innovative guide written and illustrated by America's most gifted painter of birds. Author: David Allen Sibley. Softcover, 544 pages, full-color illustrations and maps. Alfred Knopf Inc., copyright 2000. Features more than 6,600 beautifully detailed illustrations with descriptions of 810 species and 350 regional populations.