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When
Dr Karen McComb came to Amboseli Park, her first task was to learn the names of
the one hundred or so elephants most often seen.
Scientists working in the park have learned to study elephants by
watching them up close. They have a list of almost one thousand elephants.
There are records for all of the elephants born since 1972. Amboseli was a good
place for Dr McComb to study animal communications. Elephants were a great
subject because their lifestyle depends on communication.
Dr
McComb and her team had learned a lot about elephant communication, but they
kept on thinking about one puzzling (困惑的) watch.
Some families were better at distinguishing calls of friends from those of
strangers.
What
made some families smarter than others? The scientists searched their records
for an explanation. To their surprise, there was only one factor (因素) of importance: The "smartest" families always had the
oldest grandmothers. A family, as it did in all other activities, waited for
some signal (信号) from the grandmother when they heard a
strange contact call. And older, more experienced grandmothers were better at
telling whether other elephants were strangers or friends just by their calls.
That
was an important discovery. It showed how an elephant family depends on the
experience of the grandmother.
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