Animals at Play

Balls, Bubbles, Barrels & Bear Hugs

The goats at the Farm-in-the-Zoo Presented by John Deere pop bubbles with their stubby noses. The young chimpanzees nearby at Regenstein Center for African Apes wrestle with one another among the branches of the trees. The tigers pounce on sturdy plastic balls with their massive paws in the yard outside the Kovler Lion House.

These animals are playing, just as sure as the children playing ball on the South Lawn, wrestling with each other on the grass and popping bubbles that mom blows into the summer sky.

What is Play?
Some scientists are hesitant to label animals’ behavior as “play,” fearing that such a term flirts with anthropomorphism, or ascribing human traits to animals. But those scientists are in a shrinking minority.

“Yes, animals play,” says Elizabeth Lonsdorf, Ph.D., director of the Lester E. Fisher Center for the Study and Conservation of Apes. “There are still some that believe that animals are simply response-oriented organisms—that they have a hard-wired set of pre-determined responses to stimuli—but that crowd is dwindling.”
Supporting her theory, Lonsdorf cites the diverse behaviors (exhibited by varied species) that have no obvious benefit, play behaviors that are “incompletely functional.” “Animals forage to eat. They groom to stay healthy. But some behaviors are done just for fun. Just ask anyone who owns a dog.”

Who Plays?
So is play limited to dogs and chimpanzees? Not so. Nearly every species plays, according to Ph.D. candidate Matthew Heintz, a graduate student of Lonsdorf’s at the University of Chicago. Heint is currently in Gombe Stream National Park conducting a Lincoln Park Zoo-supported six-month study of chimpanzee monkeyshines. “Play is widespread among mammals from apes to zebras and the birds, turtles and octopi in between,” he says. “The most common form of play behavior occurs through locomotor play (e.g. chasing), but styles of play are just as diverse as the number of species that engage in them.”

According to Heintz, the term “play” includes a variety of behaviors, from manipulating objects to locomoting behavior and social interaction. It is “any behavior that appears purposeless, is expressed repeatedly and exhibited voluntarily.”

Why Play?
The apparent purposelessness of play can prove tricky for scientific study. In short, researchers are not exactly sure why animals play. “I don’t think we know the motivation,” says Lonsdorf, who has witnessed an octopus squirting guests at the Mall of America Aquarium and chimpanzees playing keep-away within the forests of Gombe. “Play has persisted through evolution, but understanding its function is such a tough question that many have avoided studying it.”

There are some widely accepted hypotheses. Play strengthens social bonds while providing an outlet for energy, which explains why young individuals exhibit play more commonly than geriatrics. It trains young animals to fend off predators, gives them a tool to assess their own abilities and helps develop cognition.

Play Masters
While play behaviors are observed across the animal kingdom, they are most evident in mammals, particularly primates whose intelligence, opposable thumbs, parent-rearing and social structures contribute to horsing around.

“Chimpanzees in particular play at a higher frequency than most other mammals,” explains Lonsdorf, who chuckles when recalling observing a female chimpanzee getting tickled by a fluttering cicada she was playing with, an example of what scientists call “object play.”

With great apes, play can be more complex than with less-intelligent species. For example: self-handicapping, in which a larger, more dominant gorilla will lower himself in order to wrestle with a smaller playmate. (Sound familiar, dads?)
Rules exist with play among great apes, too. Play fighting is fine until one chimpanzee slaps too hard. (Sound familiar, moms?)

The Benefits of Play
As anybody could tell you as they walk off a tennis court or golf course, play feels good. But, as Heintz highlights, scientists are beginning to look deeper than that.
The goal of the Ph.D. candidate’s study in Gombe is to determine if the stress-reducing element of play helps chimpanzee development, resulting in lower stress in adulthood and improved dominance and reproductive success. In a nutshell—Heintz is trying to determine if the best players are also the best chimpanzees.

It’s presently unsound to extrapolate that theory to ourselves, of course, but intriguing nonetheless. For, as Lonsdorf explains, play reaches its pinnacle in humans. Game on.

Lincoln Park Playground
Sure, Lincoln Park ­Zoo is a world leader in scientific research and supports conservation projects here in Chicago and around the world. But it’s also one heck of a playground. Take a look at some of the most common players:

•Young gorilla Amare will wrestle with dad, Kwan, at Regenstein Center for African Apes. It can get rough, and even resemble a fight, but can be distinguished as play by specific facial expressions and vocalizations.

•At the Antelope & Zebra Area, hoofed species like the Grevy’s zebras are given boomer balls (think large, sturdy beach balls), which they roll around their yards. When presented cardboard tigers during enrichment sessions, the lumbering Sichuan takin male puts on an impressive wrestling show.

•The chickens aren’t the only ones who enjoy popping bubbles at the Farm-in-the-Zoo Presented by John Deere. Keepers similarly enrich the ponies and rabbits, owls and goats, which respond to the bubbles with varying levels of interest. The goats—naturally boisterous beasts—climb up on keepers as they blow.

•At Regenstein African Journey, the young female rhinoceros plays with barrels, scampers around her yard and performs mock charges at the male, which is fun only if you’re the larger rhinoceros.
•At the McCormick Bear Habitat, the sun bears wrestle throughout the day, grabbing one another with their long claws and tumbling to the ground.

•When presented with paper-maché prey dummies, the puma at the Kovler Lion House pounces with the same vigor exhibited by the Amur tigers when given boomer balls attached to bungee cords.

•Nearby at the Kovler Sea Lion Pool, the gray seals toy with fish frozen into blocks of ice, violating mom’s rule not to play with your food.