The early public zoos were established in the first half of the 19th century. At that time animals were displayed as "curiosities" coming from far, exotic countries. The purpose of these menageries was to study animals' biology from a natural history perspective. With the development of the people's interest toward the environmental problems, the goal of zoos became to explain the value of ecosystems and the necessity of conserving biological diversity. To reach this goal zoos evolved from "living museums" to "conservation centres". A greater attention was paid to natural habitats and animal behaviour and the animals' enclosures were improved and transformed into dioramas or exciting "immersion exhibits". Today these centres, run by qualified staff, offer very faithful reproductions of each species' natural habitat.

Today's zoo fulfils precise functions vis-à-vis both animals and people. Firstly, it takes an active part in environmental education: it presents the spectrum of existing species together with the typical flora of their habitat, providing an ideal opportunity for biological and ethological study and research. It also acts as a breeding farm, in the best sense of the term, creating a stress-free environment for future parents and their offspring.

Although they are in captivity, animals live in an environment with a low level of genetic variation because the synergy between zoos guarantees the continuation of bloodlines. Diet is closely supervised and takes into consideration the biological phase of each species (reproduction, raising and weaning of offspring) in accordance with climatic variations.