The Sibley Guide to Birds.

Now comes "The Sibley Guide to Birds," an encyclopedic illustrated guide to the birds of North America.

He's the author of "The Sibley Guide to Birds" (Alfred A. Knopf, 2000), a vast, highly regarded and precisely detailed new bird book.

Sibley wrote the field guide The Sibley Guide to Birds.

Sibley, David Allen (2000): The Sibley Guide to Birds.

National Audubon Society: The Sibley Guide to Birds.

National Audubon Society: The Sibley Guide to Bird Life & Behavior.

The 2000 publication of "The Sibley Guide to Birds" sold 500,000 copies by 2002.

He is the author and illustrator of The Sibley Guide to Birds, considered by many to be the most comprehensive guide for North American field identification.

These days the most popular bird book is "The Sibley Guide to Birds."