Updated: March 11, 2014 13:39 IST
Elephants can decode human voices: study
Elephants can distinguish between human languages,
determine our gender and relative age and move away from those
considered a threat — all from the sound of our voice, a new study
suggests.
African elephants (Loxodonta africana) can even differentiate between ethnicities and genders, and can tell an adult from a child, the study found.
“Animals
associating sounds with danger is nothing new — but making these fine
distinctions in human voices is quite remarkable,” said Frans de Waal,
from Emory University.
Elephants in Kenya’s Amboseli
National Park are killed periodically by Maasai pastoralists. Most of
the time, the Maasai and elephants co-exist quite well, said Karen
McComb, a behavioural ecologist at the University of Sussex in U.K.
It’s
long been known that elephants flee when they encounter Maasai men
wearing their distinctive red robes — yet they are far less bothered by
other people on foot.
Ms. McComb and her colleagues
set out to determine if the Amboseli elephants could make distinctions
between the voices of the Maasai and Kamba people — farmers who live in
the same area but don’t threaten the animals.
Scientists
recorded men from the two ethnic groups, as well as Maasai women and
boys, saying “Look, look over there, a group of elephants is coming” in
their respective languages.
From a concealed loudspeaker, the team then played back the voice recordings to 47 elephant family groups.
“From
the get-go, the elephants responded differently to the Maasai and Kamba
male voices,” said study co-author Graeme Shannon, from the Colorado
State University.
They were more likely to retreat
and bunch together, forming a defensive fortress around their young, and
to smell the air if they heard an adult Maasai man speak, Science Magazine reported.
However,
their reaction was not as defensive when the voice was that of a male
Kamba. The animals were also much less fearful on hearing the voices of
Maasai women or boys.
Scientists also altered the
recordings, making the adult male voices sound more female and vice
versa. But the elephants weren’t fooled and remained vigilant.
Previously,
researchers showed that elephants will often come aggressively toward
the loudspeaker when they hear lions (their other predator) roaring,
apparently to drive them off.
But when the elephants
heard the adult Maasai male voices, they never showed this mobbing
behaviour, and instead formed a defensive bunch and retreated
stealthily.
And apparently because the Maasai men
present such a serious threat, all the elephant matriarchs, including
the youngest, knew how best to respond, researchers said.
“It’s
a key skill and is learned by watching; it’s likely not hardwired,” Mr.
Shannon said. “Older matriarchs appeared better at some voice
discriminations — in particular, telling the difference between Maasai
men and boys so that they only retreated when faced with men’s voices,”
Ms. McComb added.
The study was published in the journal PNAS.
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