20 April 2001
For immediate release
Age and experience may no longer be so highly valued in human societies, but among elephants it is still the key to successful family life.
A new study, led by University of Sussex behavioural psychologist, Dr Karen McComb, shows that the most mature female elephant of a family acts as the guardian of social knowledge. When another elephant approaches, she uses this knowledge to signal to her family whether it is friend or foe. Her social knowledge has a direct link to the reproductive success of her family as it has been found that groups with older matriarchs produce more calves.
The research, carried out on African elephants in Kenya and published in the latest issue of Science, has important implications for conservation. Older elephants are often the target for poachers because of the size of their tusks. But killing them can have serious consequences for family groups.
"We believe this to be the first statistical link between social knowledge and reproductive success in a species," says Dr McComb. "The results highlight the disproportionate effect the hunting and poaching of mature animals might have for elephant populations. Other large mammals, such as whales, dolphins and chimpanzees, also live in 'fluid' social systems, where an ability to recognise friends among many acquaintances might be expected to have an impact on reproductive success."
Dr McComb and her team, including Dr Sarah Durant of the Institute of Zoology, spent seven years gathering data on the elephants at the Amboseli Elephant Research Project in Kenya. Using high-powered loudspeakers, they played different elephant calls to elephant groups and observed the elephants' behaviour. Families with matriarchs aged 55 were several thousand times more likely to bunch together defensively in response to calls from strangers than acquaintances. Groups with matriarchs aged 35 or under were only 1.4 times more likely to follow this pattern. Older matriarchs were also more likely to lift their trunks to smell strangers.
"It wasn't obvious to us when we were carrying out the field work what we would find," says Dr McComb, who has previously studied the communication behaviour of lions and of red deer. "But when we analysed it, we were amazed to get such clear results. We were thrilled to see that we were understanding a little of what goes on in their heads."
Notes for editors
For further information, please contact Alison Field or Jacqui Bealing, University of Sussex,
tel. 01273 678888, fax 01273 877456, email A.Field@sussex.ac.uk or J.A.Bealing@sussex.ac.uk.