London, March 11 (IANS): Believe it! Not all people are dangerous and the big guys on the move know this by deciphering the way they speak their tongue.

A new study reveals that African elephants can recognise the human threat from words spoken among them in their local tongues.

Biologists Karen McComb and Graeme Shannon from University of Sussex in Brighton in the UK suggested that African elephants might be able to listen to human speech and make use of what they heard.

To understand this, they recorded the voices of men from two Kenyan ethnic groups.

Maasai, one of these groups, are known for periodically killing elephants during fierce competition for water or cattle-grazing space.

Kamba, a crop-farming group, rarely has violent encounters with elephants.

The researchers played the recordings to 47 elephant family groups at Amboseli National Park in Kenya and monitored the animals' behaviour.

When the elephants heard the Maasai, they were much more likely to cautiously smell the air or huddle together than when they heard the Kamba.

Indeed, the animals bunched together nearly twice as tightly when they heard the Maasai, said a report published in the journal Nature.

“We knew elephants could distinguish the Maasai and Kamba by their clothes and smells, but that they can also do so by their voices alone is really interesting,” explained Fritz Vollrath, a zoologist at University of Oxford.

The elephants were less likely to flee from the voices of Maasai women and boys than they were from Maasai men.

Most intriguingly, the researchers noted that elephant families led by matriarchs more than 42 years old never retreated when they heard the voices of boys.

Those families led by younger matriarchs retreated roughly 40 percent of the time, said the report.