March 16, 2011

Older Female Elephants Are Wisest

Elephants pay close attention to their elders, especially when they hear the sound of an approaching predator, researchers report in the Royal Society journal Proceedings B.

Researchers already knew that elephant social groups were organized around older female elephants. This study however, led by Karen McComb and Graeme Shannon from the University of Sussex, UK, allowed scientists to test their theory inside the Amboseli National Park in Kenya, a natural setting for the wild elephants, BBC News reports.

Researchers separated the recordings of male and female lions. Loudspeakers were then used to allow 39 groups of female elephants to hear them.

The oldest female leaders, or matriarchs, responded very quickly and appropriately to the roars of male lions by listening attentively, then gathering the herd into tight groups to defend themselves.

Dr. McComb explains, "Male lions present a very real threat [for elephants]. They can be successful in bringing down a calf even when alone." Female lions, however, are unlikely to attack an elephant unless the lions are in large groups.

The study suggests that the oldest elephant matriarchs (in particular the 60 plus age class) were more likely to engage in prolonged periods of listening and greater defensive behavior when exposed to male lion roars, and be slightly more relaxed within earshot of female lion roars.

Josh Plotnik from the University of Cambridge, studies complex social behavior in Asian elephants and called the results, "very exciting."

"My experience with Asian elephants suggests a similar trend," he tells BBC News. "Older females seem much more attuned to potential threats than younger females, which is most likely due to greater experience with a greater variety of environmental pressures."

The adult elephants may bunch together to protect young calves when hearing the male lions and were more likely to make aggressive charges towards the noise when they heard the sounds of female lions. Elephants are relatively impregnable to most predators due to their size and aggressive group defense, male lions however, present a potent threat.

Older female elephants were able to tell the difference in gender of the lions. "Younger matriarchs didn't seem as bothered by male lions as they should have been," McComb tells BBC News. "We think it's because they hadn't had sufficient exposure to that threat; lions don't [attack elephants] that often."

She added that the study illustrated a need to conserve and protect these older animals. "These older individuals clearly have a vital role in how well elephants function in their social groups. This will have a wider effect on their longevity and reproductive success."


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