One Field Guide

On BIRDCHAT this week, someone asked the following question about field guides.

If you could only have one field guide (whether due to economics, strange legislation, storage space, personal conviction or other unusual circumstance), which would you own?

Remember, only one! No hedging.

If I could only have one guide, it would be The Sibley Guide to Birds. What I like about the guide is that it includes illustrations of a range of plumage variations for every species. Both sexes are depicted if a bird is sexually dimorphic, and breeding, non-breeding, juvenile, and subadult plumages are shown, if applicable. Geographic variation is also illustrated for widespread species. In addition, I feel that its illustrations are generally more true-to-life than those in other guides.

There are some downsides to The Sibley Guide. The major one is that the complete guide is large and heavy compared to other guides, and it will not fit into even the largest pockets. (I get around that by carrying the eastern edition when birding.) A second disadvantage is that Sibley chose not to illustrate most subspecies – or at least not to label them as such. (He explained his reasoning here.) In most cases, that does not present a problem, but if the AOU splits a species (as happened with Canada Goose / Cackling Goose a few years ago), it may be difficult to tell which forms match up with which new species.

A plurality of BIRDCHAT posters agree with my choice; however, there were many votes for National Geographic's Field Guide to the Birds of North America. That guide has some advantages, especially since it is easier to carry around. Peterson and Kaufman also received significant support.

So which guide would you choose if you could only have one?