( tosha is a very quiet seismic environme...)Scientists journey to southern Africa to unravel the secret world of elephant communication

Breeding and warning

Scientists believe that an elephant's ability to converse over long distances is essential for its survival, particularly in a place like Etosha, where more than 2,400 savanna elephants range over an area larger than New Jersey.

"Elephants live in matriarchal breeding herds made up of mothers, aunts and their offspring," O'Connell-Rodwell notes. "Once males reach puberty, around age 12, they get kicked out and start traveling alone or forming small bachelor herds." The search for a mate in this vast wilderness is further complicated by the elephant's reproductive biology. Females breed when they are in estrus--a brief period of ovulation that only occurs every two years and lasts just a few days.

"Females in estrus make these very low, long calls that bulls home in on because it's such a rare event," O'Connell-Rodwell says. These powerful estrus calls carry more than 2 miles in the air and may be accompanied by long-distance seismic signals, she adds.

Breeding herds also use low-frequency vocalizations to warn of predators. Adult bulls and cows have no enemies, except for humans, but young elephants are susceptible to attacks by lions and hyenas. When a predator appears, older members of the herd emit intense warning calls that prompt the rest of the herd to clump together for protection and then flee the scene.

In 1994, O'Connell-Rodwell recorded the dramatic cries of a breeding herd threatened by lions at Mushara waterhole. "The elephants got really scared, and the matriarch made these very powerful warning calls, and then the herd took off screaming and trumpeting," she recalls. "Since then, every time we've played that particular call at the waterhole, we get the same response--the elephants take off."

Reacting to a warning call played in th
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Source:Stanford University