It's easy to take bird nests for granted. But it will be much harder to do so after reading Avian Architecture.
This book takes a look at the structures that birds build, in all their myriad forms. These are mostly nests, of course, but also included are the bowers of bowerbirds and woodpecker food stores. The variety of structures and materials is staggering; they really are amazing feats of engineering. But the best thing about this book is that it shows you how birds build these things.
Finally! I've been wanting something like this for a long time.
Here's my full review of Avian Architecture