How do zoos get their animals?
Thanks for asking! It appears that most zoos - at least, zoos accredited by international bodies like the Association of Zoos and Aquariums - acquire animals by breeding, exchanging, and buying animals from other zoos. Declining wild populations and the challenges of breeding in captivity require careful management of zoo populations and their genetic diversity. Some zoos are reported to acquire animals by wild catch and trafficking, but this is *generally* seen as a violation of professional standards.
Of course, zoo management is a complicated topic, so I'm going to post a number of sources for further reading. If you have access to an Omaha Public Library account, you should be able to open this industry snapshot from Business Insights: Global. See also these articles from Scientific American and the Zoological Society of Milwaukee. The USDA maintains a highly informative Animal Welfare Information Center, as does the Detroit Zoological Society's Center for Animal Welfare and the aforementioned AZA. If you are looking for contrasting viewpoints and analysis, you might consult the websites of organizations like PETA and CAPS.