LONDON – The hair on the tip of elephants’ tails could help humans keep them alive, says a study published today.

Researchers use the cautionary tale of Lewis the elephant to show what should be done to save the great creatures.

Scientists tracked the diet of the bull as he ate lowland grasses in a sanctuary during rainy times, then “streaked” 25 miles across dangerous human settlements to the mountains, where he ate shrubs and trees.

But the analysis shows that Lewis would occasionally raid farmers’ cornfields at night.

Those risky dining habits, probably spurred-on by a need for energy to impress the opposite sex, would eventually cost Lewis his life.

The research team combined the tracking of seven elephants in Kenya’s Samburu National Reserve with an analysis of chemical isotopes in tail hair to study their diet and movements as they hunted for sustenance, security, or sex.

This analysis and the use of radio tracking collars will help researchers anticipate where elephants are likely to come into conflict with people over crops and where they will encounter poachers.

This will help find the best place to establish sanctuaries.

In the case of Lewis, he was shot after the study was completed, possibly by a farmer.

Most crop raiding is done by bulls, probably driven by the need for high quality food to build up their strength for sexual contests for females.

“This is a new method to understand elephant behavior and help ensure their survival,” Professor Thure Cerling of Utah University said. He, Professor Fritz Vollrath, and Henrik Rasmussen of Oxford University and colleagues publish their findings today in the Proceedings of the National Academy of Sciences.

Elephants’ tail hair can grow to almost 50 centimeters at about a millimeter each day, Mr. Rasmussen said. By chopping it into small sections it is possible to study a year’s diet by analyzing “stable isotopes” of carbon and nitrogen.

Plants in dry areas such as Samburu have high levels of rare nitrogen-15 while plants in wetter areas – such as forests on Mount Kenya – have lower ratios.

Meanwhile trees and shrubs produce different ratios of carbon isotopes to warm season tropical grasses, corn, millet, and crabgrass.

So scientists can link elephants’ diets to their movements and plot maps of where they have been.

The conservation group Save the Elephants has placed 80 collars on elephants in the past decade to identify habitats and travel corridors. Mr. Cerling had isotope data from Lewis’s tail hair from 2000 until February 2002, when the radio collar failed.

The collar showed that Lewis spent rainy seasons in lowland Samburu, then trekked 25 miles to the Imenti Forest, about 6,500 feet up Mount Kenya. While in the forest, the bull made night raids into subsistence farms.

Lewis made three trips between mountain forest and arid lowlands between February and July 2002, with each 25-mile trek taking only 15 hours and called “streaking” because the elephants “are essentially going as fast as they can,” Mr. Cerling said.

“They spend their time in one area and suddenly make this dash across the country and spend a long time in another area.

“Fewer and fewer do this because the distance between safe areas is getting greater and there are more fences, more guns and more people.”