To accomplish this, they spend as many as 18 hours per day feeding. Females produce calves at intervals of about every five years. While adult elephants have no natural predators, young elephants are occasionally preyed on by lions, hyenas or crocodiles. Most physical growth occurs by age 15, and top mental ability is reached at ages 30-45. Elephants have four molars, which are replaced five times, for a total of six sets in a lifetime.
Death comes when the last set of molars wear out and the animal can no longer eat.
Although African and Asian elephants look much alike, there are several physical characteristics that distinguish them from one another. Tusks are elongated upper incisors, one on each side of the jaw. They begin to appear at age two, and grow throughout the animal's lifetime. Tusks are used for fighting, pushing, lifting and digging for water. African elephants live in socially complex 'family units' comprising of related adult cows and their immature offspring.