The lion leaps vertically, its outstretched claws snagging its quarry. Falling into a crouch, the big cat readies itself to tear its catch to pieces—which shouldn’t be too difficult, considering that its prey is actually a massive rope made out of butcher paper.
Earlier this month, the Oregon Zoo posted a video of its lions leaping, pouncing, and gnawing on, basically, gigantic cat toys woven from brown paper. But the zookeepers weren’t just toying with these creatures. Games like these are a key part of the zoo’s animal enrichment program, designed to keep their captive animals physically and mentally active.
What exactly is enrichment? It’s a somewhat nebulous concept, but it essentially encompasses a number of strategies to keep captive animals engaged. Habitat enrichment, for instance, adds diverse and stimulating spaces to an enclosure. Behavioral enrichment drives positive behavior—giving the animals a chance to behave similarly to how they would in the wild. Sensory enrichment adds new sights, sounds, and smells to an animal’s environment. And, lastly, cognitive enrichment gives them the chance to solve puzzles—often for a food reward.
Enrichment is tremendously important for the well-being of captive animals. In the 1970s, scientists found that rats raised in complex environments developed more connections between neurons in certain parts of their brains than those raised in simple cages. And this isn’t just limited to mammals. Richard Coss, a professor emeritus of psychology and animal behavior researcher at the University of California–Davis, found similar increases in neuronal connectivity in social fish that had been raised in a group, as compared with those raised in isolation.
Enrichment is even important for ensuring that animals reproduce in captivity. For small cats like lynxes—which only successfully produce offspring about half of the time—more social interactions with their human handlers lead to increased reproduction, according to a study conducted at the Oregon Zoo in the 1990s.
But does enrichment approximate what these animals would get in nature? Not always, especially because it may not be possible to replicate certain wild conditions in captivity. But while mental stimulation from interacting with humans certainly doesn’t resemble what these cats would see in their native habitats, that doesn’t mean it doesn’t help, experts explain.
“Stimulating underlying evolutionarily old motivations—which are fundamentally important to the psychological well being of animals—may not always look” the way it does in nature, says Jason Watters, the vice president of wellness and animal behavior at the San Francisco Zoo. “Everything from furniture, to electronic gadgets, to puzzles, to you name it—there’s all different forms of enrichment.”
Amy Cutting, an animal curator at the Oregon Zoo, says the term for this kind of mimicry is functional naturalism. “While you may not give a lion a wild deer to stalk and kill—a live animal—you might give it an artificial one,” she says. “They have the opportunity to stalk that prey, wrestle it to the ground, process that item, go through all the steps that they would in the natural environment. So that’s creating a functionally natural opportunity for the animal—even if it doesn’t look natural.”
And these captive animals deserve all the enrichment they can get.
“It’s a cheetah being a cheetah, a lion being a lion, a polar bear being a polar bear,” Cutting says. “That’s our goal.”