Professor Cerling, helped by James Ehleringer and Christopher Remien (two University of Utah colleagues), George Wittemyer of Colorado State University and member of "Save the Elephants" in Nairobi, and Iain Douglas-Hamilton, who founded the association "Save the Elephants", conducted a research around the Samburu and Buffalo Springs national reserves in northern Kenya analyzing carbon and other stable isotopes in elephant tail hair to discover where and what Victoria, Anastasia and Cleopatra, three daughters of a mother elephant named Queen Elizabeth, usually eat over a six-years period (2000–2006). In order to monitor their life, the elephants were equipped with a Global Positioning System that recorded their positions every hour for the whole research period. For getting the sample of tail hair, elephants were immobilized with drug-filled dart guns when necessary. Considering that the hair grows about an inch per month, a single hair contained isotopic information to diet during an 18-month period.