A BIRDER’S GUIDE TO MAINE, by Elizabeth C. and Jan Erik Pierson and Peter D. Vickery, Down East Books, 400 pages, paperback, $23.95.

Sitting in a gas station last fall waiting for the tank to be filled, I watched as a flock of Canada geese landed in a freshly harvested cornfield across the road. A moment after their feet hit the ground, their beaks did too, and they silently began to feast upon the corn that had fallen to the ground during the harvest.

I watched the magnificent creatures, common, but fascinating nonetheless, methodically begin combing each square foot of the field. I left long before they did, with a feeling of satisfaction — an odd feeling that somehow I had participated in their fall ritual of migration, merely by watching them feed.

It wasn’t until I read the newly released book, “A Birder’s Guide to Maine” by Elizabeth and Jan Pierson and Peter Vickery, that I truly appreciated the vital role open land plays in the migration, breeding and food source of many bird species.

The Canada goose may be one of the more evident species during the fall months, but it is certainly not the only bird whose existence is dependent on the resource of open land.

Building upon the success of their original book, “A Birder’s Guide to the Coast of Maine” (Down East Books, 1981), Elizabeth and Jan Pierson have compiled this definitive guide for birding in Maine. In addition to updating the information from their first book, the Piersons have added the expertise of avian ecologist Peter Vickery and expanded the scope of their book to cover the entire state.

This new release is chock-full of useful information for both the novice and the advanced birder. Maps and detailed instructions describe the best birding sites statewide, and the text offers specific information on what species are likely to be seen at a particular time.

Ponds, lakes, marshes, parks and sanctuaries are all listed with a convenient notation that tells their location in the Maine Atlas.

For those who will be traveling great distances to go birding, the authors have thoughtfully provided information for local accommodations.

This reference book will prove especially helpful next fall, when annual migrations bring huge numbers of hawks and falcons to Maine’s mountains and when many species of ducks frequent Maine’s rivers and coast.

It also has a great function year round. A comprehensive birder’s checklist of noted sightings, appendixes — including an annotated listing of birds of special interest — and index are included in this new release.

A resource list will help guide readers to other information, including books, periodicals, birder hot lines, workshops and courses, and organizations.

Elizabeth and Jan live in South Harpswell, and have been birding together since they met during an ornithology course at Bowdoin College in 1974. Elizabeth is a consulting biologist and free-lance editor. Jan is director of Field Guides Inc., which runs worldwide birding tours.

Their collaboratior, Peter Vickery, is a resident of Richmond. As a professional avian ecologist, he has written many natural history magazine articles and leads birding tours all over the globe. Vickery is author of “The Annotated Checklist of Maine Birds.”

“A Birder’s Guide to Maine” is available at many bookstores, or by calling Down East Books at 1-800-766-1670.