The premiere zoo body in the North America is the Association of Zoos And Aquariums or AZA. Association of Zoos and Aquariums An alternative group formed several years ago is the Zoological Association of America or ZAA. Welcome to ZAA.org An even newer alternative group (which I just learned about) is the United States Zoological Association or USZA. USZA | Official Site As far as I can tell, the top tier zoos are in the AZA and the second tier are in the ZAA and the third tier (only about a dozen so far) are in the USZA. Snowleopard is correct, no question the AZA zoos are the best of the bunch. However, knowing just a little bit about the politics of the AZA (from what I hear as a volunteer at an AZA zoo and from a couple of acquaintances at non AZA zoos) I can fully understand why some zoo directors flatly refuse to join AZA.
I think Arizona docent is mostly correct. At least about how the zoo bodies are perceived. In zoo reality I feel many unaccredited zoo facilities are far better actual animal facilities that many AZA. As an example many AZA zoos keep various hoofstock but can't really rival the massive natural drive in parks in the country. AZA has excellent standards and do a nice job but to me use allot of concrete and smaller environments. Seeing animals in big natural environments is awefully hard to replicate in most city zoos.
USZA appears to be a joke. They have on their site recommendations for keeping solenodons and giant armadillos.
"a joke" seems a good assessment. In their site's Conservation part they have a link for white tigers (embarrassingly enough for me, to a New Zealand site)
