Elephants have amazing hearing, as well as long memories and they can distinguish between human voices, ages, sexes, and ethnic groups, according to a study released on Monday in the journal Proceedings of the National Academy of Sciences. Being able to distinguish between human voices is an important survival skill for elephants in Africa, one which could mean the difference between life and death.
Because humans roam over a large area when they graze their cattle, elephants have a difficult time predicting when they might run into a confrontation with one or more humans.
When elephants have encountered cattle or humans, like the Maasai hunters who are in the area and who share the land of Kenya’s Amboseli National Park, they have sometimes attacked the humans and cattle. The male Maasai have often responded by attacking the offending elephant with a spear.
To the elephants, these attacks by humans seem to be random. As one of the study’s co-authors, Colorado State University behavioral ecologist Graeme Shannon puts it, to the elephants “the threat is both spatially and temporally very variable.”
Shannon is a visiting fellow in psychology at the University of Sussex. The other researchers who collaborated in the study came from both the Amboseli Trust for Elephants and the University of Sussex.
Research that had previously been conducted showed that elephants could distinguish between the sex and numbers of lions based on listening to their roars. Shannon and the rest of his team of researchers wondered if elephants also cued in on and could distinguish between human voices.
Using pre-recorded voices of local Maasai villagers of different sexes and ages, saying “a group of elephants is coming,” the researchers tested out their theory that elephants could distinguish between human voices.
Besides the Maasai voices, the researchers also included voices of the Kamba, who are known to be farmers instead of cattle herders. Farmland is relatively easy for elephants to see and avoid, so they don’t generally come into much conflict with the Kamba.
The researchers watched how elephants would respond to the voices from a Land Rover, and they videotaped the pachyderms over a span of two years. The researchers spaced out the sessions so the elephants wouldn’t become too used to the voices.
When Shannon’s iPod accidentally went off once and played “Money for Nothing” by Dire Straits, the elephants were less than impressed, and didn’t respond.
When the elephants heard the recorded voices of the Maasai men, however, they reacted by gathering closely together, and shielding the baby calves from harm. The elephants raised their trunks to try to detect the scent of humans nearby.
The reactions of the elephants when they heard the recorded voices of the Maasai boys and women and the Kamba were not nearly as dramatic. The elephants knew that hearing those voices meant that they did not face the potential danger that Maasai men posed to them, so they did not react as if they were in danger.
On thing that the researchers weren’t sure about is how the elephants could tell the difference between male Maasai voices and those of Maasai boys and women. The researchers attempted to fool the elephants by remixing the voices of the male Maasai so that they would sound more like the women, and the voices of the women to sound more like the men; but, the elephants still could distinguish the difference. How they can do this is a subject that Shannon hopes to research further in the future.
The researchers discovered that the older female elephants seemed more adept at distinguishing adult male Maasai voices. They likely have picked up this skill over long years spent listening to them, and coming to realize that adult male Maasai pose a potential danger to them.
Elephants, as the researchers detail in their study, have learned that being good listeners can also be an essential survival skill. The researchers found out that elephants know the difference between even the voices of one ethnic group when compared to another one.
According to Lori Marino, an expert on animal intelligence at Emory University, “we are now on their list of species to watch out for.”
Centuries of long experience have taught the elephants that they are most likely to experience a dangerous situation if they hear adult male Maasai voices. The study that was published on Monday is the first documented proof that elephants can tell the difference between human voices. It could be that other animals also can distinguish the difference between different human voices, but that’s a subject for further study.
Written by: Douglas Cobb