Elephants come in two species: Asian elephants and African elephants. They also divide the African elephant into forest elephants (Loxodonta cyclotis) or savanna elephants (Loxodonta africana). According to the Wildlife Conservation Society "over 60% of forest elephants have been slaughtered in the past decade". Elephants are also known as pacyderms. Elephants are the largest living mammal today. Elephants are herbivorous - that means they eat plants, and a lot of them!.
There are two reasons elephants are becoming extinct. First their habitats are disappearing because of man building cities and planting farms so the trees are disappearing (also because the elephants de-nude a forest pretty quickly because they need to eat a LOT - 400 lbs a day per animal - to give them energy). Second, man hunts the elephant both for the meat to eat and primarily to sell the tusks for the ivory.
Conservationists estimate that there are only approximately 30,000 to 35,000 Asian elephants in the wild (Very endangered) and less than 500,000 African elephants living in the wild today. That's why zoo conservation is critical to saving these endangered animals. See more about what the Denver Zoo is doing to help. Part of this story is also covered in this article.