This has been quite an intriguing battle between Taccachantrieri and Jurek7, and the stereotypical behaviour of polar bears in zoos is obviously a hot topic. The fact remains that we have all seen many different species of bears pacing in many different zoos, and even the best, multi-million dollar exhibits haven't stopped such abhorrent activities. The solution is for zoos to get rid of concrete floors in bear enclosures, build extremely large exhibits, and incorporate dirt, sand, gravel, streams and all sorts of natural enrichment in the enclosures. Then build spacious night dens and allow the animals access to them 24/7. I'm planning on visiting the famous arctic exhibit at the Detroit Zoo this summer, as well as the fairly new Toledo Zoo complex, and maybe I'll get a glimpse of efficient, effective polar bear exhibits.