A wild bull elephant strolls across the Kenyan countryside, ears flapping, oblivious to conservationist Ian Craig, creeping up behind him, gun poised.
By Ishbel Matheson
BBC News, Northern Kenya
This is no ordinary hunt. The gun is not loaded with bullets, but tranquilliser darts.
The SIM card is fitted after the elephant has been sedated
Mr Craig and his fellow conservationists hope to keep a track on the elephants in the Samburu National Park in northern Kenya, by using mobile phones, so they can send SMS messages giving their latest location.
The dart hits home, and startled, the elephant careers off.
But within minutes, the 20-year-old jumbo is lying on its side, snoring deeply.
A team of wildlife scouts dashes out of the jeep, carrying screws, hammers, measuring tape - and something that looks like a huge dog collar.
The tranquilliser lasts only a few minutes. So in a frantic operation, they heave the collar under the elephant's neck.
On the front of the collar, is a box containing a tiny chip which could help to unravel the mystery of where Africa's elephants roam.
The chip contains a SIM card "which enables us to follow the movements of the elephants on a minute-by-minute basis," says Ian Craig of Lewa Wildlife Conservancy Trust.
A few miles away, at a research station, elephant expert Iain Douglas-Hamilton and software engineer David Gachuche pore over a laptop screen. A map of Samburu flashes up, with dozens of tiny dots marked.
Each dot represents the position of a "collared" elephant. Every hour, the SIM card sends a text with the elephant's location.
Over months, entire migration routes are being discovered.
"It's important for us to learn about elephant movements, because their situation is pretty precarious," says Mr Douglas-Hamilton of Save the Elephants, a Kenya-based research organisation.
"They are an animal with great demands and needs. And they're actually living with another animal with even greater demands, and that's the human species."
'Right of way'
Before the 1989 international ban on the ivory trade, the Kenyan elephant was on the verge of extinction.
The country's herds were cut from 167,000 in 1973, to 16,000 in 1989.
Since then, Kenya's elephant population has steadily recovered.
Now, conservationists know exactly where the elephants are
But bigger herds increase the potential for conflict with the local, human population.
By mapping precise movements, the jumbos' "right-of-way" through the bush can be established.
"I'm really surprised by the variation of elephant range. Some stay in an area of 10 square kilometres. There are others who will range over 500 square kilometres," Mr Douglas Hamilton says.
The research has been made possible because the African bush is no longer as remote as it used to be.
The massive growth in mobile telephone usage in Africa means, even in the depth of the wilderness, it is possible to make and receive mobile telephone calls.
In Samburu, the mighty elephant is being dwarfed by towering mobile telephone masts.
To find Anastasia, a matriarch with the herd known as the Royal Family, we checked her most recent text position, near a dried-up river bed.
Their movements can then be tracked on a map
We found her, enjoying a lazy afternoon by the river-bank, with elephant calves playing around her knees.
This technology is in its infancy.
In future, it may be possible to warn local farmers when their crops are about to be raided by hungry jumbos.
"For example, an elephant going close to a farm, could send a text message, saying: 'I'm about to invade your farm'," says software engineer Mr Gachuche.
It would be a neat solution to a jumbo-sized problem.