Africa’s giants call long distance

Text by Conrad Brain

| This article was first published in the Flamingo November 2009 issue.

Imagine if your telecommunication company gave you only half an hour each day to make a long-distance call. You would probably make absolutely certain that you were ready to make the call the moment the lines were opened – as would everybody else – and for that time there would be a flood of long-distance calls and communication.

In today’s world of long-distance communication we tend to forget that our co-inhabitants of planet earth also have long-distance communication needs and for the largest land-living mammal on earth, the scenario of having only a tiny window of long-distance communication opened each day is as real as can be.

Elephants, like most animals, have huge communication needs. Species survival depends on getting your message across. Messages of love, location, danger, joy, desire, in fact every aspect of life and death are communicated by animals every second of the day and night. For many species, the distance from sender to receiver remains quite small and the transmissions are affected by obstacles, barriers and other physical features of the terrain.

But that’s not all. The transmission is affected by the nature of the call itself – its frequency, wavelength and other related features. The lower the frequency, the longer the wavelength of a call and the less affected it is by obstacles of terrain. Elephants are masters of low-frequency calls, so low that they are way below our hearing threshold – we probably hear only less than one third of all calls made by elephants. The rest remain their secret and scientists are working on unraveling this secret language. We can only ‘hear’ this apparently silent communication by using specialised recording equipment and then speeding up the playback ten times to bring it to within our hearing capacity.

Using this method of recording elephants, a startling discovery was made: elephant talk increased significantly at one very specific time of day – a very short period of huge amounts of elephant chatter crisscrossing savannah, forest and desert. So why the sudden and specific spike in communication? Had the telecommunication company perhaps designated a specific time to elephants for free airtime? Sounds somewhat silly, but that is exactly what is happening. The only difference is that the telecommunication company is Mother Nature (no charge involved) and the distance covered by these calls far exceeds our imagination.

The lower atmosphere of our planet is a highly dynamic space. Alternate heating and cooling of the earth’s surface sends columns of air rocketing upwards and surging back down. These events dominate conditions in the lower atmosphere and are sometimes even spectacularly visible as huge columns of dust and debris are spiraled skywards. During these conditions of unsettled air, of mixed hot and cool elemental folds, a virtual curfew of communication is imposed on those creatures relying on direct transmission through the lower atmosphere. Then as the day winds down and the sun approaches the horizon, a perceptible literal calm ensues and the communication curfew starts to lift. All forms of wildlife now take advantage of this and the talk shows begin.

Elephants are not exempt of this but have a trump card to play. They wait a little longer. Under certain very specific conditions during these periods of calm and at around 30 metres above the earth’s surface a strong inversion layer forms – an extremely narrow band of air within which there is a dramatic temperature and wind-direction change. This layer forms – for the elephants – an acoustic ceiling. The elephants are now able to generate their extremely low-frequency calls and literally bounce them off this layer, keeping them within this transmission space and sending the signal an extremely long way. It is still too early to put an exact figure to this communication distance but conservatively speaking it probably exceeds 200 square kilometres.

Understanding and researching long-distance elephant communication may provide us with critical information for their conservation in a world where their natural home ranges are being imposed upon at a rapid rate. Concepts like promoting a natural shift of large herds of elephants to new rangelands and using acoustic cues to help this could become significant as could the use of infrasonic calls as a ‘silent’ alternate in the human elephant conflict situation. Besides this, understanding the language of elephants gives us a tantalising glimpse into the culture and lives of elephants and this may even be important in understanding our position and survival on our shared earth.

Conrad Brain has a doctorate in Veterinary Science, spent 12 years in Etosha as park veterinarian and is currently the Environmental Specialist at Wilderness Safaris.