Five weeks after the rainy season starts, and three week after the proportion of grass in the elephants' diet reaches maximum levels, females in the 800-member Samburu-Buffalo Springs elephant population are most likely to conceive.
"That's never been quantified before," Cerling says.
The elephants give birth 22 months after conception, with the peak of births just in time for another rainy season to provide water and grass for offspring. Fifty to 60 calves are born annually in the Samburu-Buffalo Springs elephant population.
Cerling conducted the study with two University of Utah colleagues James Ehleringer, a distinguished professor of biology, and Christopher Remien, a doctoral student in mathematics and with conservation biologists George Wittemyer of Colorado State University and Save the Elephants in Nairobi, and Iain Douglas-Hamilton, who founded Save the Elephants and is affiliated with Oxford University.
On the Trail (or Tail) of the Royals Using Stable Isotopes
To keep track of elephants in the Samburu and Buffalo Springs reserves, Save the Elephants named different family units and many elephants within them. Cerling compares elephant families with school cliques.
"There are some elephant families that are good friends and socially near other elephant families, and some families that don't like each other and actively avoid each other," he says. The Royals are "one of the dominant families, like the cheerleaders in high school. They camp out in the best places, where the food and water are best."
Isotopes are different forms or weight of a single element for example, common carbon-12 versus rare carbon-13. The method used in the stud
|Contact: Lee Siegel|
University of Utah