In the wilds of Africa, when it's time for a family of elephants gathered at a watering hole to leave, the matriarch of the group gives the "let's-go rumble"—as it's referred to in scientific literature—kicking off a coordinated and well-timed conversation, of sorts, between the leaders of the clan.
First, the head honcho moves away from the group, turns her back and gives a long, slightly modulated and—to human ears—soft rumble while steadily flapping her ears. This spurs a series of back and forth vocalizations, or rumbles, within the group before the entire family finally departs.
This curious behavior, measured and documented in a study published in the October issue of Bioacoustics, shows how this cognitively advanced species uses well-coordinated "conversations" to initiate cooperation within the group, said lead author Caitlin O'Connell-Rodwell, PhD, a field biologist and instructor in otolaryngology at the Stanford University School of Medicine. The use of "rumbles" to initiate departure helps explain the group's ability to work together to achieve more complicated tasks, such as rescue operations to save a calf from drowning.