ANIMAL PLAY - is it a silly game or a deadly serious business?

Tom Whipple ponders if, how and why animals play in his review of 'Kingdom of Play' by David Toomey.

The scene is a wintry roofscape. The camera is shaky, low res, and zoomed in on an opposite building. There, a crow stands on the ridge of a roof. In its beak it holds a plastic lid - maybe from a yoghurt pot. Carefully, it places it by its feet, and steps on. Then, with an occasional flap to maintain balance, it slides down the snowy tiles. On reaching the bottom, it picks up the lid, flies to the ridge, and does it again. The advantage of being a snowboarding crow is you have no need for a chairlift.

If you haven’t seen the video already, go to YouTube and type in ‘Snowboarding Crow’ or ‘Crowboarding’ as it has inevitably become know.

What is it doing? It is at once utterly mysterious and not mysterious at all. We know what it is doing. It is having fun - it is sliding. It is, put more generically, playing. What else needs to be explained?

In his book, Kingdom of Play, David Toomey offers another example that rather neatly answers that question - the question of what else needs to be explained.

On the Pacific coast of Peru, there is a desolate, wave-battered spit of land that juts out into the ocean. Here, at Punta San Juan, the fur seals come to breed - in a colony that houses 20,000 members. In the January of 1988, a zoologist called Robert Harcourt, then at the University of Cambridge, settled down for some seal watching. He was still seal-watching there in October - many hundreds of hours spent watching the pups feed and frolic in a lonely epic of ethology.

Punta San Juan is not, despite its popularity, a fur seal idyll. Where the seals go, so too do the sea lions, gliding menacingly offshore, before lunging for the kill. This was what Harcourt was interested in. More specifically, he was interested in what the seal pups were doing just before becoming dinner.

On twenty-six occasions, he saw a successful kill. Most of those kills shared something in common. ‘Of these twenty-six observed kills, twenty-two of the pups were playing in the shallow tidal pools immediately before the attack and appeared to be oblivious to the other animals fleeing nearby,’ he later wrote.

Why did the sea-lions prey on the playing pups? The answer is pretty simple. ‘From observation of the attacks, it appears that pups were caught because they were less vigilant while playing. They appeared so distracted by their play that they frequently failed to join the flight behaviour of the other fur seals until it was too late.’

Harcourt was investigating the downsides of play - the costs in the cost-benefit analysis. Here was a pretty big downside. ‘Death is the severest cost possible to a young animal,’ he wrote, possibly unnecessarily.

Play cost those seal pups calories, and sometimes it cost them their lives. So, in order for it to be worth their while, in order for the trait to persist, it must have a pretty big upside. Evolution, after all, is a pretty good mechanism for pruning away pointless behaviour that kills you. So, what is that upside?

That is what Toomey, an English professor and science writer at the University of Massachusetts Amherst, attempts to answer. Play is exceptionally common among animals. Common enough, in fact, that if, inspired by the crowboarder, you solely limit it to ‘sliding’ there are still no shortage of examples.

In the Alps, in the winter, chamois deer will line up at the top of a slope, then, one after another, dive down to skid for 100 metres or more, before, like crows, climbing back up the slope to do it again. In Indonesia, snowy rooftops are in short supply, but as Toomey puts it, ‘another substrate will serve just as well.’ Elephants there will climb steep, muddy embankments and then sit on their bums to slide down. Toomey describes one occasion when a group were spotted, and they seemed to wilfully collide, knocking each other over in the process. ‘All three ended at the bottom in a great muddy heap.’

Then there’s another animal. In the nineteenth century, a large family lived in Down House, a Georgian Manor in England. The father, with ten children to keep occupied, devised a plan. He built a portable wooden slide that he could place on the stairs - intending, one presumes, that on rainy days he could still get some work done. The work he needed to get done? A book called On the Origin of Species. The father was Charles Darwin.

For a trait so evident in humans, as well as many mammals and birds, play is, says Toomey, oddly understudied. Although, it’s also not that odd that science has left play largely alone. One problem is that play is silly. ‘[A] reason scientists neglect play is,’ he says, ‘less about what behaviour in animals counts as play and more about what behaviour in scientists counts as work.’ This was not, until recently, an area that funding agencies considered worthy of serious attention.

A perhaps bigger problem is that play is hard to define. You know it when you see it - when you watch, for instance, a bonobo mother lie on her back, lift her legs up, and balance her delighted infant on them in the ‘aeroplane’ pose. Saying what play is in a way that can turn it into a scientific discipline is considerably harder.

Even Darwin, who must surely have pondered the adaptive advantage to his children of repeatedly whizzing down the staircase, avoided the subject. He ended his life writing a book on the considerably more tractable topic, The Formation of Vegetable Mould through the Action of Worms.

So, what is play? The definition that Toomey alights on, first set down by bio-psychologist Gordon Burghardt, is this: play must be an activity that is non-functional, voluntary, characterised by repeated but varied movements and undertaken when an animal is well-fed, safe and healthy.

How do you feel about that as a definition? It definitely excludes things that aren’t play. It definitely encompasses a lot of things that are play. It is also, to me, extremely unsatisfying. Somehow, it defines play without capturing the essence of play.

Sure, when a crow cackles and slides down a rooftop again and again it is repetitive, non-functional and all the rest. So too is Ronaldo dribbling a ball past a defender and putting it in the back of the net. But, I’m not completely sure that analysing the efficacy of his left foot through the Burghardt criteria gets us hugely closer to the sine qua non of play. As far as I am concerned, these criteria fail to describe play in the same way as - ‘an activity that involves putting pigment on the underside of volume-enclosing space in a manner that depicts bipeds described in 2,000 year-old papyri’ - would fail to encapsulate the wonder of the Sistine Chapel ceiling, painted in fresco by Michelangelo. Equally - and I suppose this is the point, really - I can’t do better.

This is, in any case, the easy part. The hard part, having defined what play is, is to work out what it’s for. You might think you know. Play, we are sometimes confidently told, is a means of practising. It’s how the young learn the skills they need to become old. Or maybe it is a way of socialising - of navigating, safely, the complex web of relationships that will be so crucial later in life?

Well, let’s test these ideas, on one of the best understood animals of all - a cat. Let’s look at what happens when a cat plays with a live mouse. Now, clearly, this isn’t about socialising. The mouse would take quite reasonable umbrage at that. Is it practise? It would make sense. Cats need to hunt mice, repeatedly releasing and recapturing mice should hone their skills. And it has indeed been tested.

In the 1970s, psychologist Tim Caro, looked at two groups of cats, one of which had been allowed to play as kittens - stalking, leaping, tumbling - and one that hadn’t. He expected to see better hunting skills in the former. He didn’t. “It is unclear,” he concluded, “why cats play with live prey.”

‘Of scientific mysteries,’ writes Toomey in a typically engaging section, ‘this may not be ranked with the astrophysicist’s, “Why is 90 per cent of the universe’s mass invisible?”, but it’s surprising enough to bear repeating.’ Humans have probably been watching cats toy with live prey for as long as there have been humans, cats and live prey, but we still don’t know why they do it. ‘Mind you, if the apparently inexplicable sadism of cats is a challenge to evolution, it is more of a challenge to theism.’ As Darwin put it, quoted by Toomey, ‘“I cannot persuade myself that a beneficent and omnipotent God would have designedly created…a cat [that] should play with mice.”’ Maybe, though, the experiment on cats was a freak result. Perhaps it was too small, or too artificial? Maybe the advantages, here, were too subtle? In 1996 another researcher decided to look at a different species, in the wild - and at scale.

Lynda Sharpe went to the Kalahari, took out a felt tip, marked each of the tails of some meerkat pups, and watched. Weeks became months became years, and she sat there watching. When two meerkats playfight, a few things happen. They stand on hind legs, they push against each other, they nip. Sharpe would record each instance when a play fight occurred, who was involved and who won. She counted 27,100 fights. Then, she crunched the numbers. It was a meticulous attempt to, at last, quantify the benefits of play. She knew the costs of play were high; here she was to find out what made it all worth it. The results? Did those who successfully practised fighting win more real fights? No. Maybe, then, they were more socialised - better able to take on the important roles in the pack? Also no.

If even the meerkats confound our hypotheses, where does that leave us? With, it turns out, a lot more hypotheses. ‘Despite more than three decades of research, and the postulation of more than 30 hypotheses of function,’ wrote Sharpe, ‘the adaptive significance of play remains unknown.’

Since she wrote those words, it would now be possible to add a tentative caveat, explains Toomey. In 2004, a study found that ground squirrels that played produced more offspring. In 2008, another team found that foals that played were more likely to survive their first year of life. Despite the obvious causality issues -does play make foals fitter, or are foals that are fitter more likely to play? - this came to the collective relief of ethologists.

At last, some evidence for the benefits of play. Still no evidence, mind, for what it is that provides those benefits. Why are the horses and squirrels doing better?

Here’s another theory. Play, according to ethologist Marek Spinka, is about ‘self-handicap’. When footballers play a game, they limit themselves to not using their hands. When wolves, dogs, kangaroos and rats playfight, they will often deliberately fall backwards - disadvantaging themselves. ‘It’s a fairly curious move,’ says Toomey. It might make sense if the stronger partner does it, to make it fairer - like a golf handicap. But both do.

What are they doing? They are, argues Spinka, deliberately disorienting themselves, throwing themselves (quite literally) off balance, to train for the unexpected. This, then, may be what play is: concentrated training for the unexpected.

Take, for example, says Toomey, a puppy playing in the snow. Many of us, he says, will have seen it, ‘a moment of uncertainty, a brief hesitation, then a complete surrender to the impulse, a leap and finally a joyful romping in and through the snow. The puppy’s pleasure is self-evident but, for many hypotheses of animal play, difficult to explain.’ Not so the self-handicap hypothesis. ‘Snow offers an opportunity to self-handicap, which the puppy seizes because self-handicapping is fun.’

I realise, again, that I’m getting a little Keats about this and veering dangerously close to implying scientists ruin everything by unweaving the rainbow. But in this case, it feels to me that ethologists are less spoiling our fun, than failing to understand what fun is. They are, it feels, ignoring the rainbow entirely and looking just at the rain.

Anyone who can watch a puppy leap joyfully in the snow and think it is deriving pleasure from ‘self-handicapping’ is, I would wager, missing a bit of their soul. That in itself would be fine. Soullessness in scientific study might be acceptable. But, I also - and forgive me if I get a little technical - don’t buy it. It seems to me, as a human with some experience of play, that this self-handicap idea is also missing a lot of the explanation.

It takes a pretty big act of will, to cite other examples in the book, to watch penguins repeatedly riding an ice floe down a tide run, turtles latching onto passing sharks to catch a ride, or bees playing a rudimentary game of football, and try to fit it into a ‘self-handicapping’ paradigm.

And, to be fair to him, Toomey doesn’t. He has his own, different, overarching theory of play. It is possible, he says, that it is in some sense analogous to the forces behind natural selection.

‘Play, more than any other behaviour, invites innovation,’ he writes. ‘In play we do things differently. We try things out. Sometimes, the things we try out are useful. Over several generations any inherited features that enabled an animal to learn those innovations more quickly and easily would be selected for…Thus the glove is turned inside out. Evolution gives rise to play, and in some cases play, or rather the animal that through play made that first innovation, sets a direction for its own evolution.’ Play is thus a serious business.

Could this be it? Can we, at last, explain play? Perhaps, although I don’t always follow his logic - and even when I do it sometimes feels a little tentative. I’m not alone in this assessment. Even Toomey, in truth, doesn’t sound like he is convinced.

‘What then is play?’ he asks - and admits that any answer involves contradictions. ‘Play is at once cooperative and competitive. It’s by turns destructive and constructive. It enables its participants to disregard social conventions, yet it assigns them fixed roles and imposes strict rules. All this might seem to make any effort to define play, much less understand it, futile. Perhaps it is.’

Maybe, he suggests, we should put down the book, get out a ball, head to the park and throw it around with some friends. ‘Perhaps the thing we are trying to understand is also the means to understand it. We understand play best by playing.’