First of all, I want to assure you that I'm no "Science Chimp." I have very little scientific knowledge of the birds in my backyard or elsewhere. I am, however, fairly obsessive about watching and identifying birds. If I have a day off--especially during FeederWatch season--it wouldn't be unusual for me to sit in front of the window watching birds for 4 hours (or more!)
So anyway, back to the original intent of this post. When I worked at Wild Birds Unlimited, I became more knowledgable about the birds because it was important for my job. The store sold a good variety of field guides and audio CDs for bird identification and I purchased many of them for my own use plus, I could share recommendations with the customers. The first bird song CD I purchased was John Fieth's "Bird Song Ear Training Guide," and I would listen to this CD in the car during my daily commute. I really like this CD for a couple of reasons: First of all, there are mnemonics included with each bird call (i.e., common yellowthroat sounds like "witchety, witchety, witchety"). And secondly, the birds are grouped by species, so if you've at least seen the bird enough for a partial ID (i.e., sparrow, vireo, or warbler), you can go to that section of birds and listen to them in alphabetical order until you hear the song that identifies your bird.
Especially in the spring, I listen to this CD repeatedly because I learn best from repetition. Once I start feeling more confident, I hit the random button on my CD player and see how well I do without having the birds in order. Listening to this CD has really sharpened my ID skills....sometimes I can't always remember the name of the bird and have to review the CD, but if I can remember the mnemonic, it makes it easier. Some of the more unusual birds I've been able to identify by their call (thanks to this CD) are: Common Snipe, Dickcissel, Long-Eared Owl, Warbling Vireo, and Great Crested Flycatcher.
The other CD I've used is the companion to my Birds of Minnesota field guide (by Stan Tekiela). This CD is really helpful because Stan does the narration which includes information about the bird and habitat where you're mostly likely to find the bird, in addition to the actual bird call. The one thing I really like about this CD is that it also gives the sound of woodpeckers tapping on the trees. A lot of times when I'm out in the woods, I'll hear a woodpecker tapping but can't see it. This CD helped me to figure out that was a yellow-bellied sapsucker I heard tapping on a tree.
Because I spend a lot of time out in the woods, especially in the dark, I found a couple of other CDs that helped to identify what I was hearing out there. Now just so you know, it wasn't too many years ago that I was totally terrified to be out there by myself in the dark--and hearing lots of creepy noises. However, Lang Elliot has produced two excellent CDs that helped me overcome my fear of the dark: "Wild Sounds of the Northwoods" and "A Guide to Night Sounds."
Since there are obviously no woman-eating critters in the woods of Southeastern Minnesota, there was really nothing for me to be so scared of (and "get a grip, Ruthie, you're carrying a weapon!") After listening to these two CDs, and identifying what some of those sounds were I was hearing, I now walk into the woods with no fear. In fact, it's kind of neat to hear these night-time sounds and know which birds or animals are making them.
In my collection of field guides, I have 12 just for birds. The one I like best for general ID is Kenn Kaufman's focus guide to Birds of North America. I really like the photograph format used in this book. I also like Stan Tekiela's field guides. I have 7 different ones that he's written--not just birds, but for wildflowers, mammals, and trees, too. His bird field guides are neat because the birds are sorted by color and size (from smallest to largest) within each color category. He also has produced these field guides for birds of specific states, so I have one for Minnesota and also for California (when I go to visit my brother). Some of the other states include Virginia, the Carolinas, Missouri, New York, Pennsylvania, and Georgia (they're available on Amazon.com or check at your local Wild Birds Unlimited).
So, there you go, Robin (Bumblebee)....this is probably more information than you were looking for, but aren't you glad I didn't try to put it all in an e-mail?