Only humans have language, or so humans are wont to say. Homo sapiens researchers acknowledge the wonderful variety of communication systems used by other species ― the sly chatter of ravens, the dancing of bees, the swirls of color used by squids to flash messages and warnings to one another ― but we’ve got what they don’t: syntax (the set of principles and rules for constructing sentences in a language). Or do they? Recently, researchers found syntax in the communication system of a population of Campbell’s monkeys in Ivory Coast. While this finding is controversial, my own hunch is that closer study and better tools will yield more evidence that some animals use some degree of language. Already we know that some species, like gibbons and whales, make complex vocalizations in which the order of sounds seems to have some effect on their meaning, though it is hard to say what that effect is.
I would put money on elephants. The deep bonds of affection they hold for each other and the long-lasting grief they experience as they lovingly handle the bones of fallen troupe members are evidence of a complex cognitive process.
But despite all the trumpeting, elephants are hard to listen to. Researchers at the San Diego Zoo have been studying what has been described as the “secret language” of elephants. They have been monitoring communications between animals that cannot be heard by human ears. Elephants produce subsonic growls and thumps that travel long distances over the vast expanses of the African savanna. Fellow elephants can follow these conversations from miles away, unlike human researchers, who may not necessarily have their ears to the ground.
Their growls, however, are only partly audible; two-thirds of the call is at frequencies that are too low to be picked up by our hearing. To learn more about the inaudible part of the growl, the research team attached a microphone sensitive to these low frequencies and a GPS tracking system to eight of the zoo’s female elephants. The researchers could then correlate the noises the animals were making with what they were doing.
This builds on the pioneering work of biologist Joyce Poole. For 27 years, she has lived among savanna elephants in Kenya’s Amboseli National Park, studying their behavior and methods of communication.
Distinctive expressions of joy, anger, sympathy, sexual desire, playfulness, and many other emotions are among their vocal repertoire.
Elephant researcher Caitlin O’Connell-Rodwell has looked at the language of female elephants in the mood for love. You’ve never heard it, since the message they send is strictly subsonic, but O’Connell-Rodwell knows the message is getting out there from the behavior of bull elephants. Once the girls sound the love call, the boys don’t prick up their ears, but instead hold their bodies is such a way as to hear the subsonic vibrations, which travel for miles through the ground. O’Connell-Rodwell has found that elephants actually have vibration-sensitive cells in the bottom of their feet, so something almost like ears in their feet.
But unlike earthworms, who bolt for the surface whenever they get the wrong vibe from hungry moles a-hunting, these bulls make a beeline towards where the action is.
Love is a powerful message in any language, syntax or no. So in lieu of any foot-stomping, I’ll rely on some good ol’ human digital bandwidth to send you all belated Valentine’s Day greetings.