The African elephant, the largest land animal now alive, is in danger of extinction(灭绝). The reasons are very similar to those in other cases of near extinction; the beast is the source of a highly valued commodity—in this case, ivory(象牙)—and the animal's habitat (居住地) is being more and more fenced in by human settlements. East African elephants are most immediately threatened because they are victims of an illegal trade in ivory. At the same time, a growing human population has forced all African elephants back into once remote parks, where elephant density has in many cases exceeded the natural food supply.