“The Handbook of Bird Families” by Jonathan Elphick. This is an encyclopedia of world birds as found in the 234 avian families. Species in each family are discussed in detail — world location, range, habit, size, behavior, nesting, voice, food. Some species are illustrated.
Elphick is an author and editor specializing in ornithology. He has written several other books about birds. If you have questions about the difference of one species to another, the answer is in this book.
Paperback, large format, 416 pages, with glossary, index, and reading list. Price $35. Online fireflybooks.com.