COMPLETELY REVISED AND UPDATED: From renowned birder, illustrator, and New York Times best selling author David Sibley, the most authoritative guide to the birds of the West, in a portable format that is perfect for the field. Compact and comprehensive, this guide features 715 bird species, plus regional populations, found west of the Rocky Mountains. Entries include stunningly accurate illustrations--more than 5,046 in total--with descriptive captions pointing out the most important field marks. Each entry has been updated to include the most current information concerning frequency, nesting, behavior, food and feeding, voice description, and key identification features. Here too are more than 652 updated maps drawn from information contributed by 110 regional experts across the continent, and showing winter, summer, year-round, migration, and rare ranges. This new and improved edition includes: - Updated habitat, description, behavior, and conservation text for each species account and all family pages. - New and revised illustrations of species and regional forms. - New design featuring species accounts in columns, allowing for better comparison and more illustrations and text. - Current taxonomic order and up-to-date common names. - All maps revised to reflect the most current range information. - More species and rarities included.