When people want to direct the attention of others, they naturally do so by pointing, starting from a very young age. Now, researchers reporting in Current Biology, a Cell Press publication, on October 10 have shown that elephants spontaneously get the
gist1(要旨) of human pointing and can use it as a cue for finding food. That's all the more impressive given that many great apes fail to understand pointing when it's done for them by human caretakers, the researchers say. "By showing that African elephants spontaneously understand human pointing, without any training to do so, we have shown that the ability to understand pointing is not uniquely human but has also evolved in a lineage of animal very remote from the primates," says Richard Byrne of the University of St Andrews, noting that elephants are part of an ancient African radiation of animals, including the
hyrax(蹄兔),
golden mole2(金鼹鼠),
aardvark(土豚), and
manatee3(海牛). "What elephants share with humans is that they live in an elaborate and complex network in which support, empathy, and help for others are critical for survival. It may be only in such a society that the ability to follow pointing has adaptive value, or, more generally, elephant society may have selected for an ability to understand when others are trying to communicate with them, and they are thus able to work out what pointing is about when they see it."
Byrne and study first author Anna Smet were studying elephants whose "day job" is taking tourists on elephant-back rides near Victoria Falls, in southern Africa. The animals were trained to follow certain
vocal5 commands, but they weren't accustomed to pointing.
"Of course, we always hoped that our elephants would be able to learn to follow human pointing, or we'd not have carried out the experiments," Smet says. "What really surprised us is that they did not
apparently6 need to learn anything. Their understanding was as good on the first trial as the last, and we could find no sign of learning over the experiment."
Elephants that were more experienced with humans, or those born in
captivity7, were no better than less-experienced, wild-born individuals when it came to following pointing gestures. Byrne and Smet say it is possible that elephants may do something
akin4 to pointing as a means of communicating with each other, using their long trunk. Elephants do regularly make prominent trunk gestures, but it
remains8 to be seen whether those motions act in elephant society as "points."