Some of my other favorites have already been mentioned so I am going off into
new area.

Life Histories of North American Birds, Edited by A. C. Bent. (all 26
volumes) Excellent records, some beautiful writing, and some heart breaking accounts
as they shoot their way to ornithological knowledge. Remarkable stuff.

Studies in the Life History of the Song Sparrow. by Margaret Mose Nice. Hard
to find, and expensive but this is an incredible account of simple observation
being transformed into a brilliant study. I would love to see a biography of
Nice written someday.

The Goshawk, by T. H. White. The author of The Once in Future King, White was
an accomplished falconer (warning!). This is a well written unique account of
Falconry and this particular species.

Bird of Life, Bird of Death - A Political Ornithology of Central America. by
Jonathan Evan Maslow. Learn about Guatemala through the study of the Quetzal.

Season at the Point, by Jack Connor. The birds and people and the
interactions of each in Cape May New Jersey during hawk migration. What else can you want?

Population Ecology of Raptors, by Ian Newton. Still one of the best accounts
of the natural history of Falconiformes. This book was so hard to find back in
the 70s that a professor at San Jose State University would only let me read
his copy in his office when he was there.

Birds of the Pacific States, by Ralph Hoffmann. A true classic. If you check
enough good used book stores you can probably find one. The descriptions of
the species are poetic. Paintings and drawings by Major Allan Brooks. Today's
field guides have better and more complete illustrations and they do not have
the prose of Hoffmann.