While there are many different specific personality types
, people are often categorized as either introverted or extroverted. Some like to keep to just a few close friends, rarely leaving their small comfort zones, while others are more outgoing, collecting friends wherever they go; most of us fall somewhere the middle. But we're not the only mammals with this type of social diversity. Researchers in Sri Lanka have now found that many female Asian elephants
—previously believed to be kind of antisocial—are social butterflies, changing their circle of friends as the seasons pass. Moreover, they maintain close ties with pals even after extended periods of separation. In an Asian elephant society, females and calves stick together in groups of a few individuals, called herds, while males roam about more independently, doing male things. These small bands are part of much a larger group. In the new study
, published in the journal BMC Ecology, researchers wanted to see how the relationships of individual female elephants changed over time, so they stalked nearly 300 pachyderms for five seasons in the Udawalawe National Park
in Sri Lanka. As expected, Shermin de Silva, a behavioral ecologist at the Elephant, Forest and Environment Conservation Trust
in Sri Lanka, and her team found that the elephants often stuck to groups consisting of only three adults, and some of the elephants hung out with their favorite companions throughout the seasons. Other elephants sometimes changed groups for a period, but ultimately met up with old pals after over a year of separation—de Silva says that the elephants can sustain their long-distance friendships
by communicating with chemicals and noise
. And to the researchers' surprise, some females were extremely extroverted, changing friends on a day-to-day basis; in fact, 16 percent of the elephants completely changed their "top five" friends (what is this, Myspace?) over the course of the two-year study. The researchers also found that the elephants' bonds would increase during the dry seasons, when water resources were scare—elephant friends would team up to chase away unfamiliar females. In all, the research shows that female Asian elephants live in a very dynamic society, where individuals leave and rejoin small groups at will. This behavior is similar to those seen in other intelligent mammals, like dolphins and chimpanzees, and simultaneously maintaining many relationships suggests "a high level of cognitive capacity," behavioral ecologist Phyllis Lee told ScienceNOW
. But it's not that surprising that these animals are cognitively advanced, is it? Previous research has shown that Asian elephants can cooperate with one another
to complete a task, and they have some semblance of self-awareness
. (via ScienceNOW
)
Image: Flickr/pastorbuhro
