Trunk call: jumbos learn to mimic sound

Elephants have an unusual ability to mimic and learn new sounds which scientists believe they use as a form of acoustic communication.

Birds, bats, primates and marine mammals do it but Joyce Poole, of Amboseli Elephant Research in Nairobi, Kenya, said it is the first time the trait has been found in the huge mammals.

"Elephants appear to be capable of imitating other sounds, including those that are not part of their repertoire," Poole said in an interview.

She and her colleagues recorded a 10-year-old African female named Mlaika who imitated truck sounds. She lived in a semi-captive group of orphaned elephants in Tsavo, Kenya.

Her night stockade was 3km from the Nairobi-Mombasa highway. She mimicked the truck sounds for several hours after sunset, which is the optimal time for transmission of low-frequency sounds in African savannahs.

In another case, a 23-year-old African male elephant named Calimero who was raised with Asian females in Basel Zoo in Switzerland learned chirping sounds which are typical of Asian but not African elephants.

"It was probably trying to be part of that social group and to join in with them. Eventually it became about the only sounds he made," said Poole, who reported both cases in the science journal Nature on Wednesday.

In both cases, the elephants may have learned the sounds out of boredom but the ability to mimic is another sign of their intelligence.

Elephants live with other individuals with whom they are closely bonded. But they are not with them all the time because their social groups change.

Poole and her colleagues believe vocal communication could be used to maintain contact with other elephants and for individual and group recognition.

"It is extraordinary complex and very variable - all these sounds," according to Poole.

"They are able to make sounds beyond their basic repertoire. It is yet another sign they are very intelligent and their communication is very complex."