Humans are among the very few animals that constitute a threat to elephants. Yet not all people are a danger — and elephants seem to know it. The giants have shown a remarkable ability to use sight and scent to distinguish between African ethnic groups that have a history of attacking them and groups that do not. Now a study reveals that they can even discern these differences from words spoken in the local tongues.
Biologists Karen McComb and Graeme Shannon at the University of Sussex in Brighton, UK, guessed that African elephants (Loxodonta africana) might be able to listen to human speech and make use of what they heard. To tease out whether this was true, they recorded the voices of men from two Kenyan ethnic groups calmly saying, “Look, look over there, a group of elephants is coming,” in their native languages. One of these groups was the semi-nomadic Maasai, some of whom periodically kill elephants during fierce competition for water or cattle-grazing space. The other was the Kamba, a crop-farming group that 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' behavior. The differences were remarkable. 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.
“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,” says Fritz Vollrath, a zoologist at the University of Oxford, UK (see video below).
Fascinated by their findings, McComb, Shannon and their colleagues wondered whether the Maasai language on its own was a danger signal, or whether the animals were responding to the combination of the language and the voice of an adult male who was likely to wield a spear. To find out, they recorded Maasai women and boys saying the same phrase, and monitored elephant-family responses to them.
The differences were similar to what they saw with the Kamba. The elephants were less likely to flee from the voices of Maasai women and boys than they were from Maasai men, and they bunched together less closely. 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, but those led by younger matriarchs retreated roughly 40% of the time.
It is not yet clear whether elephants are born knowing what a dangerous human sounds like or whether they can learn this from one another, but McComb suspects that the knowledge is cultural rather than innate. “Even though spearings by Maasai have declined in recent years, it’s still obvious that fear of them is high. This is likely down to younger elephants following the lead of their matriarchs who remember spearings from long ago,” says McComb.
In fact, elephants seem to be able to communicate about their encounters with dangerous people, according to a separate recent study that appeared late last month in PLOS One. It found that the animals adjusted the frequencies of their vocalizations as they meet different threats, and made a unique call when they came across swarming bees and a different unique call when they met people who traditionally hunted them. Whether these calls are something akin to language remains to be determined, but the findings certainly hint that there is much more going on in the minds of these animals than previously expected.