During courtship and migration, male humpback whales sing songs which can be heard over dozens of kilometres, typically consisting of a repeated cycle of eight or so parts made up of between two and 20 whistling, moaning, grunting and rattling phrases.
The songs have from time to time been voguish among humans; in the 1970s they were even among the recordings sent beyond the solar system by NASA.
If aliens ever hear them, though, they will be behind the times.
Ellen Garland and Michael Noad have shown that, in the South Pacific, whales regularly change their songs, with novelties moving eastward over time.
A song will appear one year among whales feeding off eastern Australia; the next year whales around New Caledonia (1,500km to the east) will start singing it; the year after it gets to Tonga, and so on until it reaches French Polynesia, 6,000km away—by which time another song will have started life in Australia.
There is no environmental or genetic underpinning for this; the succession seems a matter of fashion. Dr Garland calls it “cultural change on a vast scale”.
The vocalisations of, say, vervet monkeys have more to them. Vervets make different alarm calls for different predators, demanding different responses.
There is one for leopards (skitter up into the highest branches), for eagles (hide in the undergrowth) and for snakes (stand upright and look around). The monkeys need to recognise the different calls and know when to make which one.
Animals brought up with humans can do much more.
Chaser, a border collie, knows over 1,000 words. She can pull a named toy from a pile of other toys. This shows that she understands that an acoustical pattern stands for a physical object.
Noam Chomsky, a linguist, once said only people could do that. Remarkably, if told to fetch a toy with a name she has not heard before placed in a pile of known, named objects, she works out what is being asked for.
Betsy, another border collie, will bring back a photograph of something, suggesting she understands that a two-dimensional image can represent a three-dimensional object.
More impressive still are animals such as Washoe, a female chimpanzee which was taught sign language by two researchers at the University of Nevada. Washoe would initiate conversations and ask for things she wanted, like food.
But evidence that many animals can, when brought up with humans, tell their thoughts to others using a human language is not quite the same as saying they use language as people do.
Few have a smidgen of grammar, for example—that is, the ability to manipulate and combine words to create new meanings.
It is true that dolphins in captivity can distinguish between “put the ball in the hoop” and “bring the hoop to the ball”.
Alex, an African grey parrot, combined words to make up new ones: he called an apple a “bannery”, for example, a mixture of banana and cherry.
But these are exceptional cases and the result of intense collaboration with humans. The use of grammar—certainly a complex grammar—has not been discerned in the wild. Moreover, animals have no equivalent to the narratives that people tell one another.