Elephants are the largest land animals now living. They typically live for 60-70 years. African elephant can live 80 years. Like most other captive animals, African elephant live longer in captivity. Elephants have six teeth, some of which are continually replaced, much like sharks. Elephant tusks are actually just specialized upper incisors. These are used primarily for digging and defense. An elephant needs an average of 120-140 kg of vegetation a day to survive. As large predators are hunted, the local small grazer populations (the elephant's food competitors) find themselves on the rise. The increased number of herbivores ravage the local trees, shrubs, and grasses.