Identification of raptors can be tricky. Perched in the distance. Soaring high overhead. Similar species. Size differences subtle. Males smaller, females larger. Plumage in light and dark phases.

Many guide books offer help. Princeton Press just released a pair taking this to a higher level.

"Birds of Prey of the East" and "Birds of Prey of the West" — soft-covered 5.25 by 8-inch guide books with hundreds of painted illustrations and color photos, including habitat types.

The birds are shown perched and flying, in all color-phases. The artist zeros in on critical differences seen on heads, tails, and wings. Individual feathers are shown for some birds.

The text is, well, author Brian K. Wheeler's text is an education if you care to take the class. Most of us probably will sit-in on the lessons, focusing on our question of the moment. There is an answer.

I am a serious critic of maps in bird books. Tiny maps with confusing colors, I've written to publishers with my complaints. This pair of books has the best maps I have seen. Period.

They are big and bold, full-pages in most cases, no possible confusion on colors (some of us have color perception problems, but none here).

Maps show permanent, summer, and winter ranges. Irregular nesting sites and observations are marked. Summer, winter, and all-season dispersal is shown. In the case of the Bald Eagle a map and accompanying table indicates nesting by area and estimated number of nests (you haven't seen that before).

This is a guide book, and the maps are like having a guide at your side.

There is the usual taxonomy explanations, discussion of the books' format and the natural history text. There is text to help you understand the illustrations — why such detail? There is an anatomy and plumage glossary. Reading this will delay your trip departure, but you will be a better birder with investment of time here.

Checking Red-tailed Hawks, for instance? Pay attention to the label of the page of illustrations you see. Several ages and color morphs are covered. Know where you are. Don't confuse these books with, say, your faithful Peterson or Sibley guides. These books answer the questions those books pose.

(Princeton University Press, released June 19, 304 pages, maps, index, bibliography, guide to abbreviations, flexible binding, $27.95 each.)