Elephant feet made for talking?

Trunk call: Vibrations may provide vital information

Elephants may be listening to and communicating with each other through their feet.

Recent research by US scientists supports previous claims that elephants can interpret slight vibrations they pick up in the ground.

Speaking to BBC World Service, Stanford University biologist Caitlin O'Connell-Rodwell, said: "For people who have spent time studying elephants, this is a relief.

"They finally understand some strange things that were happening with elephants and they really are excited about it."

Good vibrations

Behavioural observations of African elephants in Namibia over a 10-year period have led O'Connell-Rodwell to consider the idea that elephants rely on more than just their ears to keep track of what is happening around them.

Underground rumblings may signify bad weather

She believes the animals pick up tiny tremors from a variety of sources - thunder from distant rain storms, animals stampeding or stomping their feet and the low pitched calls made by other elephants.

"We are focusing on the idea that elephants may be able to detect seismic vibrations through the earth," explained fellow researcher Lynette Hart, from University of California, Davis.

"That would give them information about the location of other elephants, whether they are in distress, if they are family members and also tell them something about distant weather patterns."

Social contact

By sensing the seismic waves caused by the foot stomping of their counterparts, the elephants may be able to interpret the warning signals of far-off danger.

"Research demonstrates how important communication is to an elephant," Hart said.

"They are highly social; they vocalise often and they like to maintain acoustic contact with other herds.

"If they were able to do this over a much longer distance, then elephants could forage at much longer distances in the dry season and still maintain social contact.

"They could also detect danger from further away."

Long distance call

According to the US research team, a further advantage of calling seismically is that the ground vibrations can travel further than the airborne, acoustic version of a rumble.

Geophysicist Byron Arnason told the BBC World Service Discovery programme that vocal signals could warn the animals from a great distance, but it would depend partly on atmospheric conditions.

They could forage at greater distances and still maintain contact

"In the normal situation the temperature of the air decreases with increasing height, causing acoustic energy to be refracted and directed away from the earth," he said.

Outlining further complications he added: "If there is a wind blowing the sound is carried.

"If an elephant is trying to communicate with an adjacent herd and it's the wrong time of the day, the signal may only propagate a kilometre, whereas seismic is a very stable communication channel."

Elephant's world

According to Arnason's calculations, the acoustic sound of a rumble may at best travel 10 kilometres, but the seismic version in the ground's surface layer could travel six kilometres further.

Considering practical spin-offs from this research, the American team has speculated that African and Asian farmers might benefit by having seismic vibrators buried around the perimeter of their land.

A stimulated warning rumble might keep marauding elephants well away from their crops. However, as Lynette Hart explained: "The elephant is on a different time frame.

"It is so slow yet it has a very high level of intelligence.

"It's difficult for us to put ourselves into the body of an elephant and try to make sense or ask intelligent questions that would reveal how an elephant is really operating."