Botanical gardens, zoos, and aquariums are the most conventional methods of ex situ conservation. Also in ex situ conservation, all of which house whole, protected specimens for breeding and reintroduction into the wild when necessary and possible. These facilities provide not only housing and care for specimens of endangered species, but also have an educational value. They inform the public of the threatened status of endangered species and of those factors which cause the threat, with the hope of creating public interest in stopping and reversing those factors which jeopardize a species survival in the first place. They are the most publicly visited ex situ' conservation sites, with the WZCS (World Zoo Conservation Strategy) estimating that the 1,100 organized zoos in the world receive more than 600 million visitors annually. Globally there is an estimated total of 2,107 aquaria and zoos in 125 countries. Additionally many private collectors or other not-for-profit groups hold animals and they engage in conservation or reintroduction efforts. Similarly there are approximately 2,000 botanical gardens in 148 counties cultivating or storing an estimated 80,000 taxa of plants.