The questions I am most frequently asked are, “What is the best bird book for this area?” or “What is the best bird book for identification? or “What book do you use?” Actually, I use three books most frequently.
I use my “Peterson Field Guide Western Birds” by Roger Tory Peterson, published by Houghton Mifflin Co. most often. I have many of them, covering different fields in my own library. I think I would use his bird guide if I had only one choice. I like his illustrations and the text in his books are a little longer than many other guides. He often mentions other birds that are similar to the bird you are looking up, and then he gives the differences to look for. This comparison to similarly colored birds is very useful and is even better in some of the earlier editions.
My second choice is the National Geographic Society “Field Guide to Birds of North America.” It is quite similar in format to the Peterson guide but different author and illustrators. I like to compare a bird in several different books for each drawing may show different poses and/or colors that help in identification. The color in bird books depends largely upon what colors are available in printer inks and how much rapport there is between artist and printer.
Both of these books are small, light weight and can be carried in the field.
My third choice is “The Sibley Guide to Birds,” published by Alfred A. Knopf. It is an excellent guide and shows most of the odd or unusual coloring in a species that may occur in different ages and/or sex of the species. At times, there are even illustrations of hybrids, which are unusual in the bird world. It is an excellent book, and there is a new revised edition either just out or coming out soon. The only complaint is that it is not a field guide; it weighs a ton. You simply cannot carry it in the field all day. Hopefully the new edition will be lighter. But even the old one is great to have in the car or at home.
There are many other books I use, especially if it is a bird I have never seen before or if I think it is a bird that is rare or unusual in the area. The Jefferson County Library has quite a few good bird books in the system, but you often have to wait for them to be returned by some other user or to be sent from some other library. Looking at books in the library gives you the opportunity to use the book to see if it is just what you want before you buy it.
Although I am not online, many of my friends are. They tell me that these guides are often listed on eBay. They are often much less expensive. These books are usually sold by someone who received them as a present and wants a newer, updated edition, so they are sometimes in pristine condition.
Be sure it is in good condition before you pay for any book that has been carried in the field for someone may have dropped it in the creek, or it may have dried out in the sun or be windblown until it is tattered along the edges.
Due to the recent interest in birding, there has been a rash of new bird books in recent times. The older books are still excellent for identification, but the new editions are best for getting the new names as designated by the American Ornithologists Union and for determining population trends such as the arrival and spread of the Eurasian Collared Dove in America.
Books make great presents, so let all the folks who give you birthday or Christmas presents know what books you want. All of these should be available at HearthFire Books in Evergreen or maybe even a used copy at Mountain Books in Conifer.
You could also try any of the major bookstores in Denver, or if not, you can order them.