A Field Guide to the Birds East of the Rockies, by Roger Tory Peterson. Boston: Houghton Mifflin Company. $9.95 (paperback). $15 (hardback).

Now bird lovers, from novice to expert, can more easily identify over 500 species. Roger Tory Peterson, the world-celebrated naturalist, has impressively updated his 1947 edition of this famous guide. Features include 390 New three-color range maps, a new section on how to identify birds, an updated systematic checklist, and 136 new or repainted color illustrations (the old edition had 36 color plates and 24 in black and white). Peterson's quick-reference system and fresher narrative make for easier reading, and a new waterproofed cover will protect the paperback even in the hands of the most intrepid birder.