Why animals love to play

Ask, Nov/Dec 2003 by Braaf, Ellen R

It's playtime! A leopard cub romps with its mother and swats her on the nose. A young mountain goat leaps and twists in the air. In a blur of fur, wolves chase each other through the snow. A rhesus monkey executes a perfect backflip. A parrot stands on its head. Wings spread, legs extended, two Eurasian cranes leap into the air together like ballet dancers. A garden warbler perched on a branch makes clinking sounds by dropping stones into a glass container on the ground. Young Adelie penguins knock each other off blocks of ice, then climb back up to do it again and again.

Play is a puzzle to scientists. Why do animals spend time and energy doing such silly things that seem to have no purpose? The struggle for survival in nature is deadly serious. What place is there for activities that don't help animals eat, grow, and reproduce?

And play is risky. Animals can break bones, pull muscles, or get bitten too hard. In a study of 14 Siberian ibexes (wild goats), more than one-third were hurt badly enough during play to cause limps-a serious concern in the race for survival. And animals can become so wrapped up in play that they are unaware of danger. One study showed that 80 percent of the deaths among young fur seals occurred because the playing pups didn't see predators coming!

Why is play worth the risk? Many scientists believe it's essential for survival-as important as food or sleep. According to animal play expert Marc Bekoff of the University of Colorado, "play is serious business."

Getting Ready for the Adult World

Most scientists believe that when animals play, they are practicing skills they'll need later in life. This is why different kinds of animals play in different ways. Young predators, such as wolves, lions, and bears, play by stalking, pouncing, biting, and shaking their heads from side to side. They're honing their skills for when they will run down, catch, and kill prey. When a wolf pup chases its own tail, bites it, and yanks it back and forth, the pup is rehearsing skills it'll need one day as a hunter.

Prey animals, such as elk, deer, or antelope, play differently. They dash about erratically, leaping wildly in the air-twisting, turning, and twirling. According to biologist John Byers of the University of Idaho, they act like they have "flies in their brains." But these animals are rehearsing skills they'll need one day to escape predators and avoid becoming dinner.

In many species, males and females play differently, depending upon what their adult roles will be. Generally, but not always, males tend to be more aggressive than females. Boy mountain goats play rougher than girl mountain goats. The boys charge each other and butt heads-practicing for when they will fight for mates as adults.

Young female Japanese macaques (a kind of monkey) spend most of their time playing gently and grooming playmates-skills they'll need as mothers. Male macaques prefer to wrestle, tumble, leap from high branches, and chase each other-getting ready for the time when they'll need to defend and protect the group.

With spotted hyenas, it's a different story. Adult females are bigger, stronger, and more aggressive than adult males. It's the females' job to protect and defend the pack. It's not surprising, then, that girl spotted hyenas "play-fight" more than the boys.

Dangerous Play

Besides preparing for their specific adult roles, animals at play may be "training for the unexpected," as Marc Bekoff puts it. In play, animals learn about the world around them and their own physical limits. The need to test those limits, and experience unpredictable situations, could explain why animals sometimes seem to enjoy play that is somewhat dangerous.

A study of Siberian ibexes at Brookfield Zoo near Chicago showed that even though half their enclosure was flat and grassy-a perfect place to frolic in safety-the young goats chose to play most of the time on a steep, rocky area where they were much more likely to get hurt. Why did they place themselves in danger?

Bekoff believes that such play helps animals develop flexibility-in their minds as well as their muscles-so that they are better prepared to deal with unexpected or uncontrolled events. In the confusion of fleeing a sudden attack by a predator, an ibex may stumble or crash into another member of the herd. But if it has had experience regaining its footing in play, its misstep is less likely to spell disaster.

Keeping It Fun

Through play, animals learn how to communicate with others of their species and get along with members of their group. And that can be a matter of life and death. Young coyotes spend only about one to two percent of their time playing. But if they fail to play and bond with others, they tend to leave the pack. About 60 percent of coyote pups that leave their social group die.

But how do animals find playmates? Animals can't say, "Can Scruffy come out for a game of tag?" They have other ways of inviting play.

Members of the dog family, such as wolves, coyotes, foxes, and jackals, use a play bow. They crouch down on their forelimbs, stick their rear ends in the air, wag their tails, and bark. Bears, too, perform similar bows.