We tend to think of animals as survival machines, their every action designed to help them avoid threats, fulfill needs, and find mates.
But what are we to make of a crow that repeatedly places a discarded plastic lid at the top of a snowy roof and then rides it down the pitch like a snowboard? Or orcas that drape dead salmon across their foreheads — a strange behavior that spreads to neighboring pods before disappearing entirely? What evolutionary purpose could these behaviors possibly serve?
From birds and mammals to reptiles, fish, cephalopods, and even insects, scientists continue to observe behaviors in animals that look for all the world like play. And while exactly how these activities are beneficial isn’t always obvious, researchers increasingly believe they are evolutionarily important.
“Play is a really serious business,” says Marc Bekoff, professor emeritus of ecology and evolutionary biology at the University of Colorado Boulder and author of The Emotional Lives of Animals.
Play as practice
When Bekoff first started studying play in animals about 50 years ago, most researchers treated the term as a catch-all. “Play was just a garbage pail,” he says. “When animals did things that people didn’t understand, it was just called ‘play.’”
Bekoff and other scientists have since refined the definition of play in animals. “Play combines actions from different contexts, like aggression, dominance, and predation, but in sequences that are fairly random,” Bekoff says. “So it’s just a kaleidoscope of different behaviors that you typically see in other contexts.”
For instance, consider the difference between a dog at play and a dog that is defending itself. The aggressive dog might flatten its ears, then growl, and then attack — all of which are relatively recognizable and predictable behaviors — whereas a playful dog could still growl or bite, but might then perform a play bow, or run away and come back, or roll onto its back.
“There are some very practical evolutionary reasons for play.”
Caitlin O’Connell-Rodwell
Once an activity is identified as play, the next obvious question is why the animal is doing it, and the most obvious answer is that playing is helping the animal practice a skill it will need to survive. This is called instructive play.
“There are some very practical evolutionary reasons for play,” says Caitlin O’Connell-Rodwell, a conservation biologist at Stanford University and author of Wild Rituals. “If the animal is a predator, it might be practicing how to catch its prey better. And if it’s a prey animal, it’s [practicing how] to evade that predator.”
Zebra foals, for example, play by running, chasing, and generally trying to evade each other, says O’Connell-Rodwell. Springboks, a kind of antelope, perform an interesting behavior known as “pronking,” jumping high into the air with stiffened legs. Pronking is thought to serve as a display that advertises fitness and makes a predator think twice about giving chase.
“Sometimes you’ll see an older female with five or six little ones that she’s pronking in front of and trying to encourage them to do the same,” O’Connell-Rodwell says. “So it’s interesting to see the role that mothers play in this encouragement of play. It’s really a safe zone for them to experiment.”
Lion cubs, meanwhile, swat at each other’s legs, learning how to trip another animal. They will also grab each other by the back of the neck or throat and practice chomping down — apparently testing out how hard they can bite and what it feels like to grip another animal in their teeth.
O’Connell-Rodwell has seen older male giraffes slowly walk younger males through play-fights that teach them how to spar gently and step by step. But after some instruction, they begin to hit harder. “It’s almost like Tai Chi,” she says. “But it’s always in the zone of play — until they’re old enough for it to be a territorial competition, and then it’s serious.”
The deeper meanings of play
Playful actions don’t always obviously correlate with survival skills, though, and this is where animal play becomes less understood and, arguably, more interesting.
For example, play has been linked to diffusing tension and building trust between animals. In one example, O’Connell-Rodwell recalls two subfamilies of elephants that were in the middle of a falling out. But when the groups found themselves in the same place at the same time, the calves would quickly begin to play, stymying the lead females’ attempts to keep them away from each other.
“The little ones weren’t involved in the family politics and wanted to stay and play with each other,” O’Connell-Rodwell says. “The one matriarch had no choice but to rejoin the family because her calf had decided that she wasn’t leaving the group.”
“It’s so similar to humans,” she adds, “where sometimes the next generation, by watching them play and laughing about it, is a way of unifying the larger family.”
Playful actions don’t always obviously correlate with survival skills — and this is where animal play becomes arguably more interesting.
For social animals, play also seems to serve a role in trust and bonding. “Older male elephants will get down to a younger brother’s height and let him climb on them or will spar with him at eye level,” O’Connell-Rodwell says. “This exercise deepens bonds and builds trust between the brothers.”
As for an analog in humans, O’Connell-Rodwell says we need look no further than the business world and corporate retreats. “You learn how to brainstorm better because you’re trusting each other to be silly,” she says. “Whereas if you didn’t trust [your coworkers], you’d think that they would make fun of you for saying something stupid. But you get into that zone with play.”
Some scientists believe that animals play as a way to express and even sharpen their creativity. “Animals get bored, and play could be a release from that boredom,” Bekoff says. He has observed play in coyotes, wolves, bears, and pet dogs, and it often seems to require a bit of trial and error.
“Animals have to be creative in getting other animals to play with them,” Bekoff says, adding that there can be times when animals are playing, and things verge into more serious territory — the playing animals then need to find ways to communicate to each other that they are still, in fact, playing.
“They stop and do a play bow: ‘I assure you that I’m still playing with you.’ Then they can resume playing,” he says. “During play, animals are constantly learning about how they can play with other individuals, what’s permissible with males, females, lower-ranking animals, and higher-ranking animals.”
The conditions for play
While the ways animals play can vary, when they play is a little more predictable.
While playing, animals might not be as vigilant against outside threats and could therefore be more vulnerable to predation, so it makes sense that safety seems to be a critical ingredient that allows play to develop. “In stressful environments, play is usually the one activity that just drops out,” Bekoff says.
Play also requires energy, so animals that aren’t physically fit or finding enough food might be less likely to engage in it. This also means that certain age classes of animals seem more likely to play than others — a trend that carries over into humans.
“All the data I know show that if you compare individuals of the same species, especially in wild animals, adults will play, but generally youngsters play more,” Bekoff says. “Maybe just because they’re taken care of. They don’t have to worry about feeding or protecting themselves as much.”
The fact that scientists have found evidence of play across the animal kingdom seems to suggest that it does serve some evolutionary purpose, whether it’s helping animals practice survival skills, build trust, reduce tension, or even develop creativity. But some forms of play — like crow snowboarding — may also hint at something harder to quantify: the possibility that animals, like humans, sometimes do things simply because they’re fun.
This article Animal play may be about more than survival is featured on Big Think.
