How to tell when an elephant is joking

Elephants walk at a sedate 7 km/hr or 4.5 mph, and they can keep that up for a considerable time. They have large territories, and need to keep moving, so as not to eat one area out, but when it comes to fighting their main enemy, humans, they accelerate to a higher pace.

Asian elephants know they are safer.

African elephants will sometimes engage in what is called a mock charge, but at other times, they are deadly serious. In either case, the elephant will approach, people say, at some 50 km/hr (30 mph), and reversing at this speed can be risky, so safari drivers need to know the difference when 6 tons of elephants is heading your way.

In a mock charge, the elephant’s ears are standing out wide from the head and the trunk is curled. In a serious charge, the elephant has his ears back and trunk down, but there is more to the charge than that.

They even stop by to look at the cameras.

Researchers have discovered that elephants hear through their feet, sending out rumbles at 20 Hz, so low that humans can hardly hear them.

Sound travels through soils at around 3300 metres a second, or 10,000 feet a second (that’s around 6800 mph, close to 12,000 kph), almost ten times as fast as in air, and the low sound travels amazing distances: as much as 10 kilometres or six miles.

In nature, female elephants use the mock charge to chase off lions or hyenas, and the effect of moving the ears away from the head is to make her look even larger than she is. It is possible that the sounds emitted and transmitted across the African plains also vary, but that only other elephants can tell the difference.

And given that the speed of the elephant sounds through the ground exceed the escape velocity of our planet, it is just as well that elephants cannot charge as fast as their sounds can travel through the soil!

There is just one problem with the safari-driver claims, and that is the speed attributed to the elephant: John Hutchinson and his colleagues studied and videotaped large numbers of elephants, and found the highest speed observed was more like 25 km/hr or 15 mph.

And interestingly, the elephants don’t run, even at top speed, not according to Olympic standards. The official definition of a walk is that at least one foot must be on the ground at any one time, and while elephants have been snapped with three feet off the ground, they have never been caught lifting all four at once.