Experienced female elephants act as guardians of social knowledge, listening to other elephants calls and then signalling to their families who is friendly and co-operative and who might present problems by harassing calves or starting disputes. If these senior pachyderms cant immediately recognise friends versus foes, their families may spend too much time being defensive and not enough time reproducing. The results of a seven-year study are reported in the 20 April 2001 issue of Science. The UK and Kenya-based researchers also showed conclusively that the breeding success of elephant families is linked to the age of matriarchs, the females who lead family groups.
This finding has important implications for conservation as older, larger elephants are more likely to be targets for hunters and poachers, and killing these individuals is likely to weaken entire family units for years to come.
Using data on African elephants at the Amboseli Elephant Research Project in Kenya, the researchers showed that families with matriarchs aged 55 years or over were several thousand times more likely to bunch together defensively in response to calls from families they rarely encountered than families with which they often associated. In contrast, families with matriarchs aged 35 years were only 1.4 times more likely to respond to strangers than acquaintances. If senior elephants were simply more confident and relaxed overall, they would have been less responsive to all calls. In fact, the study suggests, their social skills are better and they recognise allies more easily.
The results were gained using high powered hi-fi equipment.
Elephant calls were recorded to digital audio tape and then played
back through custom-built bass box loudspeakers in the back of a
Land Rover. The researchers then noted whether the elephants
bunched togethermeaning the diameter of the group reduced in
terms of elephant body lengths. The researchers al
Contact: Cherita Gonzales
American Association for the Advancement of Science