The Sibley Guide by David Allen Sibley is an exhaustive guide to birds in the United States. The great thing about the Sibley Guide is that he has multiple illustrations of each species showing regional differences and other variations. He is very specific and shows what you need to know to identify a species in the field. The illustrations are wonderful and educational. The draw backs to Sibley are twofold. 1) The size makes it impractical to use in the field. 2) There is little information about the behavior of the birds it covers. Still, I have one and use it all the time to study and to check something at home that I have seen in the field that I cannot place. It is an invaluable resource.
The Sibley Guide to Bird Life and Behavior contains a wealth of information. It is arranged by bird families and treats each family as a unit, using species to give specific examples of the family in general. I use it all the time to learn about birds and understand their behavior. It is not a book you can take out into the field. It is big and heavy. Because of its comprehensive nature, I highly recommend Sibley Guide to Bird Life and Behavior. It is a wonderful reference tool for birders. The only problem is that because it does deal with bird families, it is possible to find little about the particular species you are researching, but more about the family from which it comes. Still, it is very useful to the serious birder.
Sibley's Guides to Eastern and Western North America try to correct some of the short comings of the larger guide for the whole of North America. It is smaller and easier to carry in the field. It also has some rare birds for Eastern and Western North America when it seems reasonable to include them. Some complain that the colors are muted, or the pages too crowded with information. Those are minor points. All in all a good and useful guide. Many birders carry it out into the field--something you cannot do easily with Sibley's first guide.
This is a guide I have and use on occasion. It has pictures instead of illustrations. This can be helpful, but the quality of pictures for the purpose of identification can vary. The text information about the species are separate from the species, but the text does include range maps. Sometimes I consult it if I find that the illustrations in National Geographic and Sibley don't answer my questions to see if it adds anything to an identification I am trying to make.
Kaufman is a good-sized field guide that has digitally enhanced pictures. Any photograph can miss an important field mark. However, Kaufman's digitally enhanced photographs try to correct that and point out the important field marks. Some people feel this jazzes up photos too much and makes them too bright. I heard a lively conversation at an Audubon field trip about whether or not Kaufman is useful or just for beginners. There were seasoned birders who felt that Kaufman was easier to use than Sibley and liked that compact, easy to use quality. They left the Sibley guides for home study. I don't have Kaufman, but am attracted to the compact size and uncluttered look of the pages. It is next on my list. It seems like a good guide to take into the field.
I am including this for sentimental reasons. It was the first guide I ever bought. (It was an earlier 1960's edition that I bought in the 1980s.) It is great because it has it all simply in one place. It is illustrated and has range maps by the bird and not in a separate section. However, the accuracy of this guide has been questioned in recent years, and if I bring it into the field--even a more recent edition--I get comments about that. Evidently, it needs a thorough updating. That is a shame, because it is the perfect field guide to actually take with you. Small, compact, and informative.
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