Boom-boom-krak-oo – Campbell’s monkeys combine just six “words” into rich vocabulary.
Many animals have calls that are suggestive of a rudimentary language. Of course, calls are rather crude signifying systems – “signs” in the commonplace distinction, meaning that they depend on the thing they refer to being immediately present, as opposed to a symbol, a full linguistic signifier that refers to things present or absent with equal facility. Consider the difference between a stop sign, which needs to be at an intersection for it to be meaningful (otherwise, you’re thinking, “What’s this stop sign doing here where there’s no intersection to stop at?”), and the word “stop,” which in conversation can refer to an event taking place at anytime and anyplace. So animals calls signify more or less like a stop sign: they refer to the near-at-hand event that prompts them. “Mate with me,” “Danger,” “My place,” “I survived the night,” etc.
Whether apes and parrots might be capable of communicating in the full sense of language is the subject of much speculation and controversy, and outside my expertise, but I’m always pleased to find indications that animal calls are not wholly mechanical. A recent study of Campbell monkey calls suggests that the monkeys have a finite set of calls – six – which they combine in a variety of ways according to set rules. The result is a rich system of calls that can, for instance, identify a threat – leopard, eagle, or some unclear but potentially threatening activity – and even the threat’s relative immediacy. What the blog I’m linking to doesn’t discuss – and I don’t know if the original study looks into this or not – is the degree of creative freedom in chaining together the calls into a complex monkey “sentence.” It does say that the system for combining calls functions much like a human grammar in that it permits some combinations as meaningful and not others, so that, as the blog post notes, “boom boom krak-oo” means “look out for that falling branch,” but place the “krak-oo” anywhere else in that sequence but the end and it would be meaningless to the monkeys. But do the monkeys have the option to add an additional “boom” or “krak” or another call in somewhere without disturbing the core meaning of the phrase? Our own grammars, as has been frequently noted, allow for a core meaning to be expressed in an endless variety of potential combinations even if those grammars restrict the manner in which those combinations are manifested. How much expressive liberty does the monkey poet have?
It’s enough to make me wish I had the time to look into the current science of bird calls as well.
Wood Thrush 