The Warbler Guide (above) & App (below).

The Warbler Guide enables you to quickly identify any of the 56 species of warblers found in the United States and Canada. This award-winning guide has proven to be the favorite among birders and features more than 1,000 stunning color photos with extensive species accounts, and a new system of vocalization analysis that helps you distinguish songs and calls. Learn all you can about this interesting group of songbirds through the 560 pages of this authoritative book. There is also an associated App for you to download to your mobile device or cellphone.

For more information from Princeton University Press about The Warbler Guide by Tom Stephenson and Scott Whittle, see https://press.princeton.edu/books/paperback/9780691154824/the-warbler-guide

The Warbler Guide App is the perfect companion to Princeton’s widely acclaimed book The Warbler Guide. This innovative app delivers the full power of The Warbler Guide in your pocket along with unique new app-only features. Exciting new 3D graphics enable you to view a bird from the exact angle you see it in the field, and the whole range of warbler songs is easily played, compared, and filtered. The app quickly helps you identify birds by observation or by songs, quickly and intuitively. See https://press.princeton.edu/books/app/9780691196534/warbler-guide-app