An interesting book is "Captive Beauty: Zoo Portraits by Frank Noelker (published in 2004). It is a fairly large, glossy collection of exactly 50 photos of zoo animals. Many of the shots show animals against murals, or in environments where human-made structures are evident in all directions. For example, photo #28 has a grizzly bear in an outdated pit at Paris Zoo in 1998, photo #3 has a giraffe inside its indoor quarters at the Bronx Zoo in 1997, and photo #31 has a white tiger against a painted mural at Baton Rouge Zoo in 1999.
A couple of the photos have the wrong labels, and it is essentially a photographic journey that is borderline anti-zoo. My favourite part of the entire book is the writing section, which is comprised of an emotional forward by Jane Goodall and a terrific, 14-page introduction by Nigel Rothfels (author of "Savages and Beasts: The Birth of the Modern Zoo").