April 23, 2018

By Eli Baskir, Behavior Research Associate

For most of us, the rewards for what we accomplish during the week aren’t gold medals—the 2018 Winter Olympic games are over. Daily tasks might seem routine because you’ve mastered them, but consider how you felt when you were first introduced to a new assignment at work or school. Were you excited? Did you focus your attention? Did you rise to the occasion? Even Olympians have to start somewhere, and the challenges they face bring out their incredible skills. But, after they master the easy stuff, what’s next?

Like humans, animals have physical abilities and problem-solving skills they use to escape danger and find food. Evidence suggests that encountering challenging situations and improving competence is exciting for many species, including great apes. The activity required to complete such a challenge can be a great workout (just ask an Olympian). We also know that some animals prefer to work for resources that are otherwise offered freely; for them, just like most humans, completing a difficult task can be rewarding on its own.

If you do the same thing over and over again, however, it’s just not difficult anymore. This is the same for animals, and giving them new objects doesn’t necessarily guarantee their interest. Rather than trying to continually introduce novel things all the time, what if an animal is given a task that can capture their excitement and attention each time they use it? Such a puzzle would have to be challenging, and it would have to stay challenging even as it is mastered.

In zoos, introducing challenges appropriate to animals’ skills is our responsibility. Discussions about complexity and novelty led to the development at the Saint Louis Zoo of a concept we call Progressively Challenging Enrichment (PCE). PCE recognizes that animals need challenge but can’t be given the most difficult puzzles first—imagine trying to learn calculus before addition! Instead, challenges must be introduced at an appropriate level based on an animal’s skills, and then gradually updated to increase engagement.

Before Centene Grizzly Ridge was built, a sloth bear named Daisy lived in one of the former Bear Dens. Sloth bears have a unique way of eating—­they use their mouths to vacuum insects out of old logs! Our keepers wanted to encourage this behavior, so they designed PVC tubes of different lengths. One end of each tube was open, and the other was closed with food items like berries “glued” to the inside with honey. Keepers discovered that as Daisy was presented with the more challenging, longer tubes, she spent more time vacuuming. This enrichment had benefits that extended past her mealtime, as Daisy would be more active those afternoons, spending time interacting and investigating her habitat.

The next time you visit the Zoo, think about the design of certain enrichment devices that you may see in the animals’ habitats and how they can be made more challenging. You might notice that some of the monkeys at the Primate House have feeders that resemble the game KerPlunk. The object of this enrichment is for the monkeys to get to the grapes inside the device by removing the sticks so that the grapes tumble out as a reward. In a future visit, you may see that the monkeys have to pull more and more sticks out to get the grapes to fall!