This is the latest incarnation of the Doctor Doolittle question. You can replace ‘prairie dog’ with chimpanzee, parrot, dolphin, gorilla and find that someone, somewhere, has reported research findings that say an emphatic, “YES!”. The BBC showed a programme a couple of weeks ago in which Dr Con Slobodchikoff, a biologist from Northern Arizona University, had the best part of an hour to convince me about his research. You can download it here:
or if you don’t have a spare hour, you can listen to a short interview he gave to public radio in the USA:
Dr Slobodchikoff has found that prairie dogs (burrowing squirrel-like creatures) have an assortment of alarm calls in response to various predators: dogs, coyotes, humans, snakes, hawks. Having spotted danger, a prairie dog whistles in a particular way and the other members of the group (or ‘city’ as it is called) take the appropriate evasive action, which appears from this film to consist always of running down a hole. There are similarities here with vervet monkeys (not mentioned in the film, though they should be) which have three distinct alarm calls (eagle, snake, leopard) provoking very different evasive action. If the vervets hear the call for eagle, they hide deep in the canopy of a tree; if they hear the call for snake, they stand on their hind legs and scan the ground; if they hear the call for leopard, they climb on to the thinnest branches of a tree where a big cat cannot follow. Because the vervet responses are so well matched to the alarm call, you can see an adaptive advantage at work here; you are less likely to get killed if you react in a way that thwarts a particular predator’s modus operandi.
But, party pooper that I am, I cannot allow that this useful behaviour is language. It’s three alarm calls for three predators. No vervet can communicate anything else that might be dangerous, such as Landrover, man with gun, erupting volcano. And this is an important lack because the really special thing about human language is that describing new things is no problem at all. You may well never have seen a spaceship of purple hippos taking over Buckingham Palace, but you will know about it if someone puts that new image into words.
Back to prairie dogs. Dr Slobodchikoff claims to have identified dozens of calls that are able to convey not just the kind of predator, but also its size, colour, and speed. Prairie dogs, he says, can be shown to whistle in a different way if the approaching predator is fast or slow, tall or short, wearing brown or yellow pants. The film gave no evidence for this, annoyingly, nor said how it had been tested. It was just an assertion. But you could test for it pretty easily. Have a series of people of the same height approach the ‘town’ slowly, wearing either brown or yellow pants. You should get an acoustic signal for the resultant alarm call that differs in one way only; just as in human language, ‘slow-moving medium-size human in yellow pants’ differs in only one way from ‘slow-moving medium-size human in brown pants.’ Until you have done the same with all the other ‘words’ in this language, you won’t convince me that the prairie dog has the slightest idea of how to encode colour or size or speed into a whistle.
Undeterred, Dr Slobodchikoff in his radio interview at least, becomes very ambitious. He is working, he says, on decoding prairie dog whistles into their constituent parts, which are inaudible to the human ear but show up as distinctive patterns in digital analysis. Now you can do this for human voices. Speech can be broken down into its constituent parts—phonemes—and you can show how a string of phonemes such as /pet/ differs from another series such as /bet/ and gives you a different word. Having sorted that out, you can analyse the way words follow each other and reveal the constituent parts of the grammar. Dr Slobodchikoff is claiming he will do this for prairie dogs, making the massive claim that not only do these creatures have all these different words, they order them in rule-governed ways. Now it gets very silly indeed. Dr. Slobodchikoff envisions building a machine for two-way communication between prairie dogs and humans. We would encode a human utterance into a rule-governed whistle, and play it to a prairie dog and wait for the answering whistle which the machine would translate back into English. This is daft on so many levels I don’t know where to begin, but I would just ask, WHAT DO PRAIRIE DOGS WANT TO TALK TO US ABOUT? As far as we know they only vocalise when they spot danger. So all they ever say is WATCH OUT WATCH OUT WATCH OUT WATCH OUT WATCH OUT WATCH OUT WATCH OUT. Even if Dr. Slobodchikoff is right and, for no apparent adaptive advantage, prairie dogs have evolved a way of communicating the colour of a man’s pants, it’s still only vocalised in warning calls. And don’t forget, we are still waiting for the research evidence that shows you actually can isolate meanings like ‘yellow’ from whistle data.
The radio interview ends with Dr Slobodchikoff speculating that in time we’ll have a machine that we can use to ‘talk’ to our pets with, so that we can decode the dog’s barking. As lovely a dream as that sounds, I am completely confident it won’t ever be true. Dogs wag their tails to show they are excited, growl to deliver a warning, snarl to show they are dangerous. The level of threat or excitement is expressed by intensity of wagging or snarling. But like all animals, their communications are rooted in responses to stimuli in the immediate present. They are not capable of wagging their tails to express yesterday’s excitement; or growling to show what they think about meeting a rival dog again; they cannot snarl for a laugh, pretending to be threatening; they cannot apologise for chewing your shoes last week. But human language transcends time and place; allows a speaker to reflect on things that have never happened; express dislike of yellow pants even if they have never ever seen a pair of them; and lie about things which did happen but which are best covered up. And it’s grammar (morphology and syntax) that makes this possible. If you want to know if language has developed in another species, you have to look for more than alarm calls or expressions of emotion. There has to be structure. No grammar, no language.
This is not to say that prairie dogs cannot communicate. They can, most certainly. But they don’t have language, and cannot ever engage in an inter-species chat with us. Sorry.