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Big Talkers
Earth's largest land animals have a lot to say—even when they
don't seem to be making a sound.
Thirsty and hot, 12 elephants plod across the fried African landscape. The water hole is less than a mile away now, and everyone in the herd is looking forward to a good, long drink. Tired calves want to stop, but mothers and aunts nudge them along. The older animals make soft, soothing noises. "We're almost there," they seem to say. "Just keep walking."
Suddenly everyone stops. Huge ears stretch out like satellite dishes. After a minute or two of what seems like silence, the animals turn and walk away from the water hole—fast. As they go, the adults huddle close to the calves.
So what happened? Why did the elephants change their course? They seemed to be listening to something. And whatever it was, they got the message to flee! Yet human ears heard nothing.
Elephants make plenty of sounds that humans can hear, such as barks, snorts, roars, and trumpet-like calls. Often a herd will use such sounds to talk with other elephants. But they weren't in the air this time.
Second Language
For years, elephants puzzled observers with this type of behavior. But now scientists have solved the mystery. They discovered that elephants have a "secret" language they use for communicating over long distances.
This special talk is based on infrasound, sounds so low in pitch that humans can't hear them. The sounds can travel for several miles, allowing the six-ton animals to keep in touch across grasslands and forests in Africa or Asia.
To study elephant infrasound, researchers use special equipment that can record low-pitch sound waves. Another machine, called a spectrograph, translates the recorded sound waves into images, or markings, that we can see. The images stand for various messages.
Translating infrasound helps scientists begin to understand elephant behavior. For example, it turns out that the elephants heading to the water hole may have heard warning calls from another herd. Perhaps a lion was slurping water and looking hungry. The cat would be no match for an adult elephant, but it might kill a calf. No drink would be worth that risk, so the herd turned away.
Long-Distance Calls
Elephants use infrasound to communicate many types of messages over long distances. Some of their talk helps hold families together. To understand how this works, you need to know a little about elephant families.
Females spend their lives with mothers, sisters, and children. They form tight-knit herds of 10 to 20 members. The oldest female elephant—the matriarch—takes charge. Males live with a herd until they are teenagers. Then they depart, living alone or joining with other males in a "bachelor herd."
The members of a herd often scatter over large areas to seek food for their mighty appetites. (An adult elephant can eat 300 pounds of grass and plants in a single day!) Long-distance calls let elephants know where their relatives are. And when the matriarch says, "Come here!" the herd gathers within minutes.
Like curious kittens, elephant calves sometimes wander off and get into trouble. When that happens, they cry for help. Adults respond with infrasound calls and other noises: "It's okay. We're coming to help you."
Adult males and females often live far apart, so they use infrasound to find each other at mating time. Females mate only once every four years or so. When a female is ready, she makes a special series of calls. Males who hear the calls storm toward her. Sometimes two or more males battle fiercely for a chance to court the female.
Hearing Aids
Elephants tune in to all this talk with their large, powerful ears. An African elephant's ear can grow to be six feet long and four feet wide. (Asian elephants have much smaller ears.) When straining to hear something, the animal turns toward the sound and opens its ears wide.
At the same time, the elephant may raise its trunk to sniff at the wind. Elephants have a keen sense of smell. Odors may help them figure out what they're hearing.
Elephants may have yet another way of learning what's going on around them. Although scientists haven't proved it, some think elephants can actually feel infrasound as the sound waves travel through the ground.
Distress Call
Communication skills help Earth's largest land animals survive in the wild. But even these skills can't save elephants from extinction.
In 1997 Africa's elephant population was about 500,000. That may sound like a lot, but there were 1.3 million African elephants in 1979. More than half of the elephant population vanished in only 18 years.
How did this happen? Poachers killed many elephants for their ivory tusks, because ivory can be sold for a lot of money.
And a growing human population wiped out vast amounts of elephant habitat to build farms and towns. Elephants from these areas wandered into human settlements. Some elephants ate valuable crops and made some farmers angry enough to kill them.
How Will We Answer?
Conservationists are working hard to save elephants. Wildlife groups are trying to persuade people around the world to stop buying ivory.
Elephant supporters are also working with African communities to maintain parks where elephants can be safe and will not harm crops. Some conservationists hope that tourists will visit these beloved animals there. That would mean jobs for local people, who would then view elephants as a valuable resource to protect.
Text by Peter Winkler
This article appears on pages 4-7 of our September 2001 issue
Creature Feature:
Find elephant audio and video, a map of the animals' range, and more!
Elephant Information Repository:
Get Jumbo-size information on elephant anatomy, behavior, and conservation.
The Lost Elephant:
Kids use their knowledge about elephants to help a baby elephant find its mother.
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