Norma Fischer, age 12, of Sioux City, Iowa, for her question:

WHAT IS THE LIFE SPAN OF AN ELEPHANT?

The Indian elephant has a longer life expectancy than the average worldwide human population. Aside from man, he has no serious natural enemies. In the wild, the big fellow lives a fascinating life, full of peaceful tranquillity. For example, would you believe that he spends most of his long life purring in his own special way?

The African elephant may stand 10 1/2 feet tall and weigh 6 tons. Barring accidents and food shortages, he can expect to live 50 years. This is somewhat longer than the average life spans among several human populations of Africa. The Indian elephant is a foot or so shorter and weighs only about 4 tons. But his average life span is around 70 years.

    The life of a wild elephant is centered in his herd of friends and relatives, where each member contributes to the protection of the entire group. Every few years or so scientists learn something new about their fascinating ways.  But surely the newest bit of information is the most fascinating of all.

It is well known that the wild herd creates elephantsize tummy rumblings, heard perhaps a mile away. Observers blamed these gassy rumblings on their enormous meals of vegetation. Now we know that this is not the whole story.

Scientists noticed that the noises are controllable. When strangers approach, an elephant stops rumbling. Other elephants within range also stop, and the signal is relayed. If the strangers depart peaceably, the rumbling resumes otherwise the herd makes arrangements to, protect itself. The tummy rumblings are a sort of purring sound, used continuously to keep in touch with each other.

This strange purring is one of many protective devices that the average elephant uses to enable him to outlive the average human. However, elephants, like people, have population problems. With no serious natural enemies, they tend to multiply too fast for their food supplies. Unless the thriving herds are reduced, they devour all the vegetation and face death by starvation.