Mr. Barton has been active in birding and conservation in the New Jersey area, and perhaps because of his long career in advertising, and as a nature columnist, he writes entertainingly, and best of all, knows when to end a paragraph. He does not chitter on about birders' joys, but concentrates on the birds -- sightings he has made from the Atlantic, ""Middle,"" and Pacific flyways. There is a section on insects and plants and throughout pleasant oddments for the sojourning birder: a brief and rewarding visit to the old Chesapeake and Ohio Canal, a discussion of ""life zones"" at Yosemite, observations on the declining bluebird population, etc. Barton closes with a chapter on environmental protection, which offers some firm advice and information for those prepared for ""personal participation, with daily work and boring chores."" In spite of Mrs. Barton's tendency to exclaim ""By gravy!"" when spotting a boreal chickadee, the Bartons are models of 20th century birders -- alert, companionable and contributing -- By George!