In elephant family groups made up of related females and their young, it is clear that the animals produce vocal sounds to coordinate action. This happens when it's time to leave a waterhole, for example. The matriarch or dominant female steps away from the waterhole and turns to the direction she intends to move in. Then she flaps her ears as she makes a short call referred to as the "let's go" rumble.

What follows is a highly coordinated "conversation" of sorts. The female elephants in the group add their own rumbles, each waiting for the previous individual to finish what it has to say first.

Elephants coordinate action so that they can remain together (at least within acoustic range), while moving to the next resource. It is safer for females and their offspring to travel as a group to protect their young from potential predation.

Male elephants also live in groups, often referred to as bachelor herds. But it's never been clear how they coordinate their actions. Previous research using camera trap data seemed to show that subordinate males simply followed older males to resources.

Ever since my husband and I worked for the Namibian government from 1992-1995, we have been returning to Mushara waterhole to study the resident elephants. Since 2004, I have brought a team of researchers to help me, and we have returned every dry season to follow the lives of known individual elephants to learn about their group dynamics, coordination and communication.

• Read More