What are the advantages and disadvantages of keeping animals in zoos? By the year 2050 scientists predict that one quarter of Earth's animal species will become extinct. Species are rapidly losing their habitats due to the growth of the human population. This is happening both in the rainforests of South America and even in Britain. Housing development and agricultural growth put pressure on our own native species. Perhaps one of the main reasons for the existence of zoos is to preserve and protect the animals, which are endangered by such human development. Another purpose they serve is to make it possible for people to learn about these animals by making you able to see them in conditions, which are as close as possible to the natural ones without having to travel the world. The question we have to consider is do zoos really achieve these goals