How elephants communicate: A whole new world of secret conversations

Posted on Wed June 24, 2020.

WARNING: By reading the following article, you are at risk of having your mind blown...

From the powerful, high-pitched trumpets and roars that echo throughout the landscape to the tender, low-frequency rumbles of a mother comforting her baby; elephants communicate in many different ways.

Here, Elly dives into the fascinating world of elephant communication and discovers that these gentle giants may just be talking about us behind our backs...

Animal communication is a topic that has captivated me for as long as I can remember. There is no doubt that human speech is an evolutionary masterpiece, but our gift of the gab pales when you begin to explore the special ways that other animals are 'talking' to one another.

My favourite example of this is elephants. On many occasions, my guests and I have been fortunate enough to sit quietly with a herd of these peaceful pachyderms as one of the leading females ushers her family away with a harmonic rumble, reminiscent of the growl made by T-Rex in Jurassic Park. But, what exactly is the meaning behind these sounds?

In much the same way as humans have developed language to communicate, elephants have evolved an intricate array of different sounds that are a fundamental part of their complex social lives. In the example above, an elephant may be using these rumbles to communicate to her family "Let's go" and using her body language to signal the direction.

Elephant families that have been temporarily separated may also engage in a kind of greeting ceremony, touching each other with their trunks and letting out a different rumbling sound to show their excitement at being reunited. This kind of interaction is key to cementing the close family bonds within a herd and developing a cohesive sense of teamwork.

Elephants are also known to 'talk' to one another about potential threats, including one of their least favourite co-inhabitants: honeybees. Bees can be dangerous if elephants get stung around their eyes or in their trunks, and the thin skin of baby elephants also makes them more vulnerable. As a result, elephants have a developed a specific 'anti-bee' rumble that serves as a warning signal to others in the area.

If an elephant calf is hungry, it will make a soft 'begging' rumble while walking beside its mother, lifting its trunk and touching her mammary glands as a sign of its desire to feed. Obliging mothers will respond by moving their front leg forward and allowing the calf to feed, whereas those trying to wean their infants may deny them access to milk, often resulting in the youngster making a 'cry' in protest - the equivalent of an elephant tantrum!

When a human baby cries, the vocal cords vibrate in an irregular manner which produces a sound that is very harsh to our ears. Interestingly, the exact same vocal mechanism is used by baby elephants when they scream or roar. For humans and elephants alike, these sounds are difficult to ignore and both species are hard-wired to respond to make sure the youngster is not in danger.

In the wild, predators may be lurking around every corner. If a baby elephant is attacked by a lion, for example, it will let out a piercing scream and its mother and other adult females will rush to its aid. They may use threatening trumpets and roaring to scare off the predator and return the calf to the safety of the herd.

This threatening display of foot stomping, ear flapping and roaring may serve a purpose well beyond scaring off a lion, however. It simultaneously provides a warning signal that can travel several kilometres through the ground to alert other herds that danger is present and scientists have only recently managed to unravel the mystery around this type of communication.

'Infrasounds' are sound waves with a frequency that is too low for human ears to pick up. At less than 20 hertz, these powerful sounds provide elephants with kind of "private" communication channel. Given low frequency sounds can travel much further than high frequency ones, this is perfect for long-distance communication across a vast African landscape. But, how do they manage to create such sounds?

A team of voice researchers and cognitive biologists removed the larynx from an elephant (that died of natural causes) and manually blew air through it while manipulating the vocal folds. They found that elephants are able to produce these sounds using the same mechanism that humans use when they sing, except their immense larynx produces notes far lower than our strongest contralto or bass singers!

These super low frequency sound waves travel as vibrations through the surface of the ground, known as 'seismic' communication - a term usually used when referring to the vibrations cause by earthquakes. Elephants have two systems for sensing these seismic vibrations, which I will attempt to describe for you without getting too technical...

The first is bone conduction. This is when vibrations travel from the tips of the toes, through the foot bones, up the leg and into the middle ear. The second has a funky name: 'somatosensory reception' - try saying that three times fast! In laymen's terms, this describes special cells in the base of the foot that can detect these vibrations in the earth and communicate this information directly to the brain via nerves.

A couple of years ago, a team of researchers worked out a way to 'eavesdrop' on these secret elephant conversations using equipment typically designed for monitoring earthquakes. These tools allowed them to listen to vibrations in the ground as elephants moved about and vocalized to one another.

Elephants appear to rely more on detecting vibrations through the bones in their feet than the sensory receptors, positioning themselves at a right angle to the sound so that their ears are at different distances from it. This helps them to pinpoint the direction of the vibrations, which is particularly important if you are a male searching for a potential mate.

Female elephants in estrus (that is, ready to mate), will put out a type of 'estrus rumble'. In doing so, she hopes to attract the attention of some handsome, high-ranking bulls who will receive her advertisement, ascertain which direction it is coming from and head off in search of this enticing mating opportunity.

An elephant's trunk also contains a high concentration of these special vibration-sensing cells, known as Pacinian corpuscles, and researchers have watched elephants press their trunks against the ground to more effectively determine the source of this seismic communication. Males seem to do this more than females do, although it is currently not clear why this is the case.

It is simply mind-blowing to imagine that these gentle giants are having multiple silent 'conversations' from kilometres apart, conveying information about everything from potential danger to possible mating opportunities. Next time you are on safari and you see an elephant pause, press its trunk to the ground or rest quietly on its tip-toes, imagine what fascinating message he or she might be listening to. Above all, don't forget to be kind to an elephant - you never know when they might be talking about you behind your back!

 

Article written by Elly Gearing with photos courtesy of Nerise Bekker and Elly Gearing.