Hi Kaufman Field Guide to Advanced Birding is an excellent guide. There is over 30 pages devoted to just the 8 most challenging hummingbird species. Also a few years ago John Vanderpole published an excellent video guide, along with John Dunn, on North American Hummingbirds
Cheers, Bob Righter Denver, CO -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/9E734FD3-BE10-40FF-960D-575E97DD2CCA%40earthlink.net.
