July 29, 2006, 12:43AM
A new field guide that you can actually carry in the field

By GARY CLARK

Birds common in Mexico often wander up to Texas, particularly in the Rio Grande Valley, but also in other parts of the state, as well. That's why it's a good idea have handy a field guide to Mexican birds.

Most such field guides are not easily carried, but a new paperback guide by Ber van Perlo, Birds of Mexico and Central America, is one you can toss in your rucksack or stick in your hip pocket.

The book is a pocket guide, not a comprehensive reference guide like Howell and Webb's Guide to the Birds of Mexico and Northern Central America (Oxford University Press, $39.95). Yet the little book has an amazing breadth of information, and a quick thumbing through leads you to just about any family of birds you may want to find.

The book illustrates and describes the more than 1,500 birds that occur from Mexico to Panama, including Belize, Guatemala, Honduras, El Salvador, Nicaragua and Costa Rica. The color illustrations are beautifully rendered, though in many cases the images are small.

But thumbnail pictures are OK if accurately portrayed, and most birds in van Perlo's field guide are portrayed rather well. Male, female and juvenile plumaged birds are illustrated along with "races" (although defining races in birds is sometimes controversial).

An example of a Latin American bird with two races is the brown jay that resembles a magpie and frequently shows up along the border of South Texas. It has two putative races that are shown in the field guide (Plate 72), one with a white-tipped brown tail and one with an all brown tail. The latter bird is the one that shows up in South Texas.

Some birds that occur in Latin America are migratory and breed in the summer in North America. So, when you bump into a bird in Latin America like a wood thrush that breeds in East Texas, it's helpful to see how it compares with resident Latin American thrushes like nightingale thrushes (among my favorites of Latin American birds). This guide carefully illustrates the thrushes for comparison.

I have two criticisms. First, the book illustrates birds in isolated profile, not in dynamic action within their habitat such as shorebirds feeding on beaches or trogons perching in trees. Second, it uses a gray-scale layout for the distribution maps in the back of the book rather than color maps, which would have been easier to decipher.

Naturalist Gary Clark and photographer Kathy Adams Clark can be reached at http://home.houston.rr.com/wondersofnature/.

http://www.chron.com/disp/story.mpl/life/4080237.html