Diet secrets of 'the Royals'( SALT LAKE CITY April 13 2009...)

SALT LAKE CITY, April 13, 2009 Two weeks after the rains begin, an elephant family named "the Royals" usually switches to a grass diet to bulk up for pregnancy and birth. But when they wandered off their African reserve one rainy season, cattle grazed the grass so short that elephants couldn't eat it, according to a University of Utah study.

The research which suggests how climate change and human encroachment may affect endangered elephants was led by Thure Cerling, a distinguished professor of geology and geophysics, and biology. He used Global Positioning System (GPS) tracking collars and analyzed carbon and other isotopes in tail hair to monitor the elephants' movements and diet from early 2000 to early 2006.

The study involved Victoria, Anastasia and Cleopatra three daughters of a mother elephant named Queen Elizabeth, who died of old age the first year of the study. The findings are set for publication Monday, April 13, in the online edition of the journal Proceedings of the National Academy of Sciences.

The research was conducted on the African savanna in and around the Samburu and Buffalo Springs national reserves in northern Kenya.

"Fifteen years ago, there was a lot of poaching in the area, and elephants were getting killed," Cerling says. "But in the past 15 years, security has improved considerably, so people are moving in with cattle. Now there's a suggestion the elephants are finding it harder to compete with the cattle than with the poachers."

The study also showed an intricate interplay in the timing of the rainy season, the growth of grass, when the elephants eat grass, and when they breed and give birth.

When rains begin, satellite measurements show increasing greenness as grasses grow. Two weeks later, after grass has grown long enough for elephants to grab with their trunks, elephant tail hair shows a ratio of carbon iso
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