written by: Andrea Campbell
• edited by: Tricia Goss
• updated: 5/4/2015
Chances are good you've seen animals playing. Perhaps you have even seen "friendship" between two species, such as your family's cat and dog. Learn more about whether animals actually play, make friends and have emotions.
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Wildlife photographer Norbert Rosing once captured an image of a sled dog playing with a polar bear. The 1,200-pound bear was frolicking, wrestling and rolling around with the dog, without aggression, and without hurting the dog. Rosing was surprised to see that the bear returned every night for a week to play with the sled dogs.
Zoologists and others who study animals wondered if animals learned how to play from their mothers or if it was a basic instinct, a pattern of behavior, now called ethology. There is a problem however, in that play theory has not received much serious research. Scientists are afraid of anthropomorphizing –attributing human characteristics to animals—and then not being taken seriously.
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Animals at Play
We know a great deal about primates—monkeys and great apes—because they are closest to us on an evolutionary scale. Guenons, a forest-dwelling monkey in West Africa, can be found chasing and being chased by squirrels. In the same way, the playful primate will also tease birds, such as when a flock of hornbills roost in a tree; the monkey will shake the branches, scare them away and create a mock attack. The birds return and settle down, and the monkey waits and does his act again.
In fact, nearly all animals play.
A playful animal is generally relaxed and repeats play, experimenting and repeating locomotion. What do animals gain from play? Play generally involves running, jumping, leaping and so forth. Objects are something to hit, chase, push or carry. One benefit may be socialization, a process by which a young animal gains the knowledge and skills it needs to be part of a community.
Researchers have also found that animals in play benefit from dopamine, a chemical that occurs in our brain that helps to create feelings of pleasure. This chemical may be expelled into animal brains when they do things that mimic serious behavior but with a gentler, lighter version.
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A man named Konrad Lorentz was one of the pioneers of ethology. The Austrian examined the behavior of ducks and geese using an interesting approach. When baby ducks hatch, the first person they see they recognize as “mother." Lorentz experimented with this phenomenon and discovered that young hatchlings bonded with him and followed him around as if he were their mother. He named this behavior “imprinting" and published his findings.
Dutch zoologist Nikolaas Tinbergen shared theories with Lorentz. He expanded the idea finding, that the young birds raised with humans showed no fear of humans. In addition, they were not afraid of cardboard cutouts of shapes, yet when shown cardboard shaped like eagles or hawks, they were afraid even though they’d never seen them before as predators.
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Hundreds of examples on YouTube show two or more animals wrestling, rolling or jumping on each other. It can look like friendship or courting. The best or most interesting type of play however, is when different species play with each other—when cross-species play.
Tame or home-raised animals often play together. This has also been documented on farms and in zoos. Another interesting occurrence is when animals that play have different strengths, are predators or even play-fight. Photographer Hugo Van Lawick observed an adult African gazelle playing with two young bat-eared foxes. Although their normal prey is mice or insects, the foxes are actually predators, but the gazelle chased the foxes in circles.
When two animals “play-fight," one usually plays the role of the attacker and the other defends itself. Two animals in the same species might change roles, practicing both attack and defense.
Animals that play together are not always evenly matched. One may be bolder, bigger, stronger than the other is. To make up for its size, a larger monkey for example, may crouch, slow its movements or self-handicap to keep from hurting the other animal.
In cross-species play, this is usually the case as well. One animal deliberately gives itself a disadvantage in order to initiate and engage in animal play as equals.
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Trained to Be Friends
Since 1981, trainers at the San Diego Zoo and Safari Park have paired cheetahs with dogs at an early age. The zookeepers claim that the dogs have a socializing effect on the skittish cats. After time and some companionship, the activity helps them to take the cheetahs out to public events, where they can use the animal as ambassadors for the zoo.
According to one spokesperson, it is “grooming, not playing, that cements a dog-cheetah friendship." In the beginning when the puppies are introduced the young cheetahs are fearful. Gradually however, the two animals begin to trust one another until eventually, the cat will relax, licking and grooming the dog as their normal licking behavior shows through.
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Owen and Mzee
A cross-species relationship spawned a book and became a YouTube sensation. This true story of the remarkable friendship between an orphaned baby hippo and 130-year-old giant turtle found millions of viewers around the world.
Owen, the hippo, was stranded after the December 2004 tsunami and villagers in Mombasa Kenya rescued him. The orphaned hippo and an elderly tortoise, Mzee, became inseparable, swimming, eating and playing together. Eventually, the grownup hippopotamus was introduced to Cleo, another hippo. Cleo—unlike her hippo friend Owen—hurt a different tortoise. Owen and Mzee had to be separated. Children were disappointed expecting another generation of hippos and turtles to bond.
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Koko and All Ball (Gorilla and Cat)
Koko the gorilla, who learned American Sign Language at the Gorilla Foundation at Stanford University, received a stuffed animal and became upset. So on her birthday, they allowed her to choose a real kitten from a litter and she named it “All Ball"—they say as a joke because the kitten looked like a ball.
When her playmate and kitten friend (whom Koko had nurtured as a mother) died and she was told about the tragedy, she pretended not to hear her keepers at first. Then she whimpered, as in mourning.
Her trainer said about the incident: “Koko then said, ‘Sleep. Cat.’ by folding her hands and placing them at the side of her head."
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Anne Innis Dagg, who has a PhD in animal behavior and teaches in the independent studies program at the University of Waterloo, says historically, researchers haven’t studied friendship among animals with the same enthusiasm they have shown in studying aggression.
She claims, “One researcher called the study of animal friendships the ‘F-word in primatology.’"
People that have disdain for animals don’t like comparisons in behavior that mimics humankind. That, too, and zoos would have additional problems trying to facilitate pairings that work out. But Dagg says the tide is turning. More people agree that animals have feelings and senses, suffer when they are hurt and form alliances.