At this very moment, millions of wild animals are kept in captivity in 10,000 zoos all over the world. Locked up in enclosures infinitely smaller than their natural habitat, in artificial environments that have little to do with their original savannah or forest, these animals can experience great suffering. Many of them end up with stereotypies (which are abnormal repetitive behaviors, a sign of psychological suffering). Boredom and frustration drive animals to incessant pacing, constant rocking, compulsive grooming and self-mutilation.
In zoos, enclosures are built primarily to enable visitors to easily observe the animals, often at the expense of their tranquility. As the animals are frequently exposed to noisy crowds and sometimes forced into contact with humans, they suffer from stress, which lowers their quality of life even further.
To justify their lucrative business, zoos tend to claim they protect endangered species. However, most species found in zoos are not threatened with extinction. From a conservatory point of view, their captivity is therefore of no benefit. The selection of species exhibited to the public is often based on the emblematic nature of the animals, not on conservation criteria.
Moreover, almost all animals in zoos were born in captivity, making it difficult, if not impossible, to return them to the wild. Whether they belong to endangered species or not, these animals will never be reintroduced into their natural habitats. In short, the argument that zoos contribute to the conservation of species simply doesn't stand.