I'm not sure about other regions, but here in the US it's pretty common for zoos and aquariums to have temporary exhibits. They usually are usually a one year thing, attracting guests during the summer or spring. Here are some examples
Minnesota Zoo's Africa, Kangaroo, and Llama Exhibits
Exhibits with temporary frog or jelly displays
White Alligators (NC Zoo, Hogle Zoo, Brookfield Zoo) or Koalas (Santa Barbara Zoo, Kansas City Zoo, Indianapolis Zoo)
Sometimes even giant animatronic "bugs" or dinosaurs
Does anyone have any other examples?
Minnesota Zoo's Africa, Kangaroo, and Llama Exhibits
Exhibits with temporary frog or jelly displays
White Alligators (NC Zoo, Hogle Zoo, Brookfield Zoo) or Koalas (Santa Barbara Zoo, Kansas City Zoo, Indianapolis Zoo)
Sometimes even giant animatronic "bugs" or dinosaurs
Does anyone have any other examples?