Tracing Social Networks of the Asian Elephant

Some social Asian elephants with many companions face the same difficulty, a new study reports. Other elephants are more reserved and instead maintain a few strong relationships.

Shermin de Silva and her colleagues tracked the behavior of nearly 300 female elephants in Uda Walawe National Park in Sri Lanka for about two years and found that elephant social networks are complex, and that behavior varies quite a bit.

Their work appears in the current issue of the journal BMC Ecology.

“There’s a lot of individual variation,” said Dr. de Silva, who conducted the research as part of her doctoral thesis at the University of Pennsylvania. “Each individual is free to choose their own companions.”

Most elephants gathered in groups of three, although a group could be as large as 16. And while certain elephants stuck to the same companions for long periods, others moved around.

One group of five elephants seemed to always stay together. About 16 percent of the observed elephants completely changed their top five friends during the study period.

“If you think about it, the amount of time you can devote to a friendship decreases with the number of friends you have,” Dr. de Silva said. “The fewer friends you have, the more strongly bonded you are with those few friends.”

It is not clear why the elephants choose to move from one social circle to another, said Dr. de Silva, who now runs the Elephant, Forest and Environment Conservation Trust, an organization she founded in Sri Lanka.