Elephants 'do have long memories'

In the study, when families were played male or female lion roars from a loudspeaker -- simulating their presence -- those with older matriarchs correctly focused their defensive reactions on male lions that are the more adept killers.

Dr Karen McComb of the University of Sussex, who led the study, said the ability to make this subtle distinction highlights the importance of age in leadership and advantage of longevity in large-brained, social mammals.

Elephants live in multi-generational families of up to 12 members that feed, rest, and move as one unit. Together they defend each other, search for food and also care for offspring.

During 72 playbacks of lion roars among 39 family groups in Boseli National Park in Kenya over more than two years, the oldest matriarchs listened intently for longer periods and led their group into more defensive positions when it was a male roar.

The researchers said: "Our work provides the first direct experimental evidence that older matriarchs are in fact able to make better decisions when faced with ecological challenges in this case, the presence of dangerous predators."

They added: "The findings demonstrate how the accumulated knowledge of the oldest individuals may have an overriding influence on the effectiveness of anti-predator decisions made by the social group as a whole, and highlight the vital role of such individuals in natural populations."

The findings have been published in the 'Proceedings of the Royal Society B' journal.