Credit: Courtesy of San Diego Zoo Wildlife Alliance Top 5 Can’t Miss See some of the San Diego Zoo's thousands of rare animals while knowing a portion of the admission price aids conservation efforts.Hang out with giant pandas at the Smithsonian's National Zoo in Washington, D.C.Head to Vienna to visit the oldest zoo in the world, the Schönbrunn Zoo, which dates from the late 1700s.Learn about wild animals in the middle of New York City's urban jungle at the Bronx Zoo.Watch the famous crocodile demonstrations and marvel at Down Under wildlife at the Australia Zoo, where the Irwin family carries on Steve Irwin's conservation work. Catching a glimpse of your favorite animals up close can be a thrilling experience. And while zoos may be controversial, many of them provide a good opportunity for people to learn about the global environment and the work being done to preserve critical species for generations to come. When planning a visit, make sure your chosen zoo is as ethical as possible.…