Animals for entertainment. These include animals in circuses, game parks, rodeos and zoos. Except for rodeo animals, these are often unusual animals from other countries. For instance, they include apes and monkeys; bears, including polar bears; common, native and exotic birds; dingoes and other wild dogs; lions, tigers and other big cats; giraffe, moose, hippopotamus, rhinoceros and other grazing animals; common and uncommon reptiles and many others. These animals have special needs in their natural state and when kept for entertainment. They are studied to ensure that those special needs can be met and so that they can be kept in a good state of welfare. In zoos, they are also studied to help save endangered species.