The Rule Of Four

Lecturer: In today’s lecture I’m going to continue the theme of animal communication, and I’m going to describe some of the latest research into the largest of all land animals. And that is theelephant, of course.

Let me begin by briefly outlining the structure of elephant society. Elephants live in layered societies. The basic family unit is formed of small groups of adult females, who arerelated to each other, and their young of both sexes. Now the females remain in their families for life, they’re highly social, but male elephants leave their families at about fourteen years of age.They travel alone or congregate in small, loose groups with other males, occasionally joining a family on a temporary basis. When males are ready to mate they wander widely, searching for receptivefemales.

The family unit, on the other hand, often contains three generations, and it can remain stable for decades, or even centuries. Then … each family associates with between one and five otherfamilies, probably consisting of their more distant relatives. Scientists call these groups of families ‘bond groups’, and bond groups belong, in turn, to even larger groups, called clans.

Soelephants have a complex social structure. And like other social animals they have to be able to communicate. But what baffled early naturalists was their ability to communicate over long distances. So theyset about researching this question.

In one experiment, scientists fitted groups of elephants with radio-tracking collars. And what they observed about their behaviour really intrigued them.Because they found that there was some sort of co-ordination between families. For example, two separate family groups might move in parallel to each other, miles apart, and then change directionsimultaneously, either turning or moving towards each other. Now elephants have a keen sense of smell which they use whenever they can. But smell alone couldn’t account for these synchronized movements,...