“Mais Robert le perroquet n'a dit rien” - Raymond Queneau, Zazie dans le Métro.
The sense of humour is usually regarded as a uniquely human phenomenon, based on an appreciation that things need not be as they actually are, and reliant on a sophistication of language that belongs only to our species. I would maintain, however, that some birds have sufficient language skills to be able to indulge in verbal trickery; and that some birds, namely those that are commonly ranked among the more intelligent, enjoy that sense of mischief that is conventionally attributed to certain primates.
Wild creatures in most environments are aware of a continuous noise made by all the other creatures that surround them. They learn to interpret these sounds in order to avoid predators and to locate food sources. Indeed, I recently came across a story of a fugitive from the Nazis who avoided capture because he had learnt to interpret the calls of robins and blackbirds. The African drongo goes a stage further. It will, by imitating other birds' alarm calls, drive them off their food, allowing the drongo to usurp a meal.
[Note: the Australian insult, calling somebody a drongo, has nothing to do with the bird. Drongo was the name of a racehorse, which, being the progeny of winners through the lines of both sire and dam, attracted large wagers from the Melbourne punters. Unfortunately the horse remained a hopeless also-ran. Hence “drongo” means “loser”.]
Here we see a possible origin of mimicry skills among birds. The drongo is not displaying a sense of humour; only purposive behaviour. But what about the common starling? I once came across the local blackbird singing outside my house as usual, but something did not seem right, and when I checked, I observed that it was a starling that was singing the blackbird's personal song. What on earth for? Perhaps it was to let the wider world know that it could. Perhaps it could also imitate the blackbird's alarm call in order to steal other birds' food, like the drongo. I never caught it doing that, however.
This bird went a stage further. In those days the traditional heavy telephone with a circular dial was being replaced by the smaller and more elegant Trimfone. Instead of a bell, this device had as its ringtone an electronically produced buzzing sound. The starling would perch on the windowsill of a householder with a Trimfone, imitate the device's characteristic ringtone, and dance up and down with glee when the householder picked up the handset and spoke into it. I would contend that this behaviour demonstrates a sense of humour of at least the level of that evinced by the small boys who place a turd on a doorstep, cover it with paper, light it, ring the doorbell, and dance up and down with joy when the householder stamps out the flames in his carpet slippers.
The Indian Hill Mynah is perhaps the most prodigious mimic in the bird kingdom. And the mynah is a starling. Before CITES (Convention In Trade in Endangered Species) it was easy to acquire a mynah. There used to be regular court cases involving nuisance caused by mynahs imitating car alarms, cockerels, industrial machinery, just about anything. Interestingly, every single mynah bird in captivity could say “Pipe down” or “Shut up”.
Of course, the bird that is best known for imitating human speech is the parrot. A friend taught his wife's Amazon Green Parrot to speak Latin simply to astonish visitors. Occasionally, to attract attention, it would say “Euphorbia antisyphilitica”, which is the name of a Mexican succulent that used to be boiled down to make furniture polish. Once, while I was visiting, my host answered the telephone to an uninvited salesman. Very quietly, he laid it down beside the parrot's cage. The bird was ecstatic; it hung upside down with one ear pressed as close to the telephone as it could reach. At length, presumably the caller had reached the end of his spiel, because the parrot said “Hello?” There followed a few more minutes silence from the parrot, but it was obviously getting bored and restless. Eventually it shrieked “Show us your knickers!”.
Parrots are notorious for their bad language. Of course, they do not understand human speech, but they are very sensitive to human behaviour and will enjoy provoking a reaction. I remember the parrot keeper at Whipsnade Zoo chasing small boys out of the parrot house where they had been teaching the birds rude words. In bygone days a young seaman would buy a parrot in Rio or Recife as a present for his sweetheart back home. But while the sailor was engaged on his duties elsewhere, his so-called friends would amuse themselves by teaching the parrot all manner of indecencies so that the sweetheart would get a nasty surprise.
My parents took me to one of George Formby's last ever stage performances. The great man was clearly not in the best of health, and he was obviously trading on public affection that he had earned during his previous stellar career. The only joke of his that I remember concerned a pious old lady who owned a parrot that swore. She used to cover the parrot's cage with a black cloth on Sundays so that it would not profane the Sabbath. However, one Tuesday evening the vicar paid an unexpected visit. As she ushered him into the sitting room she rushed to pull the black cloth over the parrot, which called out “That was a fucking short week!”
A true story along the same lines reached the British national press. The mayoress of a town in the Midlands (I think it was Nuneaton, but it may have been Tamworth) was paying an official visit to a small zoo in the town. Close behind were the Lord Lieutenant of the County and the Chief Constable, and they were followed by a gaggle of newspapermen, which explains how the story became public. The mayoress approached a large macaw that was sitting on a stand (the macaw's name was Norman, by the way), and said “Pretty Polly!”. The macaw replied in ringing tones “Why don't you fuck off?” The mayoress stepped back in shocked surprise, so her entourage pressed forward to see what was the matter. At this the macaw screamed “And you lot can fuck off and all!”
The crow family are famously intelligent. Magpies sometimes pull off the imitation trick. Nowadays some of the local magpies have learnt to imitate the mewing of kites. Ravens are famously cunning and manipulative. Though in the south of South America the ecological niche that is normally occupied by crows is filled by caracaras, which are technically eagles but which have the resourcefulness and monkey tricks of ravens. Just after the Falklands War a scientific expedition went to South Georgia. The scientists pitched their tents, then set off to explore, but not before rigging up a motion-sensitive television camera to monitor the campsite. The film shows an invasion of caracaras. One bird systematically pulled out all the tent pegs. Others raided the tents and pulled out everything that was inside. One caracara even manged to drag out a butane gas bottle that must have weighed several times its own weight. Finally, another bird worked its way along the ridge poles, slitting the canvas with its beak as it went. All this was performed with every appearance of enjoyment, just like human vandals.
The nearest I have seen to this kind of behaviour is by blackbirds, which will pull plant labels out of plant pots if they get the chance. One imagines that they are looking for insect larvae or something. I would not have thought that this is done out of a sense of mischief, except for the fact that cats do exactly the same thing and they are certainly not looking for insect grubs.
In conclusion, I suggest that our species are only unique in the sense that we have developed certain abilities to a greater extent than other species have. We are different by degree, not in essence. Years ago the myth that man was the only tool user was disproved by observations of chimpanzees using stones to break nuts, Galápagos finches selecting cactus spines in order winkle grubs out from their hiding places, and various other similar examples. The honey guide using human beings to rob bees' nests that they cannot rob by themselves is comparable with us using dogs to herd sheep, for example. Furthermore, I believe that the language of at least some birds is quite sophisticated and that one day researchers will be able to achieve some measure of understanding that will surprise us.