The senses of an elephant

Elephant rush to a water hole - Hwange Game Reserve, 1975

Gary Gerhardt wrote an excellent and informative article in the Adventure section of the Rocky Mountain News on Saturday 1st July, 2006, describing how animals have developed super-acute senses of smell, vision and hearing to give them a survival edge. (See "Elevated senses are common attributes.") The article reminded me of a personal experience in the 1960's that brought home just how sharp the elephant's sense of smell is. The elephant's vision is poor and its hearing is good but its sense of smell is amazing. 

In 1968 I was employed by the Government of Rhodesia (now Zimbabwe) as an Entomologist in the Tsetse Control Branch (See note below.), and was on an extended, 7 month, field assignment in the southeast of that country on the border shared with Mozambique. A typical work day began about an hour before sunrise when leaving my tented camp and ended around noon. This avoided the hottest part of the day from noon until about 3 p.m. Returning to camp for a light lunch I would often go out later in the afternoon to explore the remote areas of Mozambique, looking for water holes and doing plant and game population assessments. 

Elephants were of particular interest to me. Tsetse Flies are always found in areas with specific vegetation types and where game densities are high. They can be carried great distances by elephant and elephant routes were important to explore. Elephants often engineer the primitive road networks of remote bush areas.

One afternoon I was by myself. Normally I would have a companion but for some reason on this particular day I had ventured out on my own. I drove along a rough track for several miles, took my bearings and left the Land Rover to hike to a prominent rocky feature I had seen on some aerial photographs. I left that rocky "outcrop" and crossed a 200 yard wide open grassy valley before stopping on another high rocky spur. The wind had been blowing from my left and when I was about halfway across I saw a small herd of elephant approaching from my left a considerable distance away. I knew they couldn't smell me because of the strong wind blowing from them toward me. 

Reaching the opposite high ground, I sat down and turned to look back across the open grassland and watch the herd, still walking at a leisurely pace toward where I had crossed. I could see the path I had taken quite clearly as there was a straight line of bent grass to mark my route. What happened next was remarkable. 

The instant the leading elephant reached my track, she halted abruptly. The others fanned out on either side of her and as each one "touched" the imaginary line my scent had created they stopped. It was as though an electrified fence had suddenly been erected in their way. Each member of the herd, about 12 or 15 in number, became agitated, sniffing the air with trunks extended, flapping their ears, and several trumpeted repeatedly. Their distress and confusion continued for about a minute, until the herd's matriarch turned and led them away at high speed back in the direction they had come. They absolutely would not cross the line I had unintentionally left with my scent. I was too far away for them to see me and they certainly couldn't hear me.

This was an extremely remote area but I had seen evidence of poaching. The game was undoubtedly familiar with human scent. What amazed me was the acuity of the elephant's sense of smell. With a strong wind blowing I would have thought my scent might have dissipated but that was not the case. I suspect the elephant's sense of smell is similar to that of the bears that Gary Gerhardt wrote about in his 2006 article.

Note: The Tsetse Fly carries the human "Sleeping Sickness" pathogen. This pathogen also causes "Nagana" which kills domestic livestock and is therefore of significant economic importance in Africa.