Cayucos with wall puzzleThink of a game that’s a cross between pinball and pool, using a hollow ball stuffed with shrimp and played by a high-energy sea otter, and you’ve got the latest product dreamed up by Northwestern engineering students for Shedd. Sea otters and trainers agree—this new puzzle is a big winner.

The puzzle is a 44 x 32 x 6-inch box of thick plexiglass that fits into the window opening between the sea otter pup pool and the trainers’ area. On a recent afternoon, Cayucos, an almost-2-year-old southern sea otter, is poised to play. Standing upright on her hind feet on the ledge around the pool, her paws on the puzzle’s front panel, she peers through the clear plexiglass for trainer Lana Vanagasem to start the game.

But first Lana, who is manager of sea otters and penguins, grabs a blue 5-inch feeder ball—a tough hollow sphere with small holes in it, designed specifically for hard-playing aquarium and zoo animals—and pokes 11 large shrimp into it. Now she’s ready to begin the enrichment session—a half-hour of stimulating play that literally keeps the inquisitive otter on her toes.

Cayucos, a perpetual motion machine, has been hopping in and out of the water, but now she’s back at the puzzle. Facing Cayucos, Lana drops the ball through a hole at the upper left-hand side of the back panel of the puzzle. No sooner does it thud onto the uppermost of three staggered plastic shelves than the otter pup has her paw through one or another of the evenly spaced openings along the shelf to bat and spin the ball so that the shrimp might spill out.

“The goal,” says Lana, “is for her to move it along to the end of the shelf, where it drops to the next level, then take it across and down to the bottom level where there’s a hole where she can get the ball—and the shrimp.”

Although Cayucos has played this game several times—she’s the best at it of the four sea otters—Lana notes, “Sometimes it takes her a little while to remember. She’s just trying to get the shrimp out now. But that reinforces her to keep playing.” (See Cayucos, on the left, do the puzzle with Mari in the video above.)

Cayucos has spent a full minute whacking the ball back and forth along the top shelf when it finally goes through the opening to the shelf below. “That’s one level!” Lana cheers.

The otter grabs at the feeder ball through the holes, sometimes using both paws, spinning it until it spews shrimp on the shelf. Hard plastic rolling on hard plastic sounds like a bowling ball. It takes Cayucos only 30 seconds to send the ball to the final level.

But now she’s energetically pawing through the holes to reach the spilled shrimp, which she can see from above and below the clear shelf. The flexible animal bends herself upside-down and hits the shelf from below, stymied by why she can’t get the tantalizing shrimp like she could if it were in the water.

But sea otters seldom spend more than a few seconds on anything, so she’s back at the ball on the bottom shelf, smacking it hard to the end of the shelf where she can get it. Top to bottom, it takes Cayucos just 3 minutes and 45 seconds to get the ball out. Now she goes back to the shelves to pick up the last of the shrimp.

“She really is good with this window,” Lana says, still laughing over Cayucos’ efforts. “It’s fun because you can change the configuration of the shelves. Once we have more shelves made, we can make it more complicated.”

The puzzle is the latest product to come out of a longstanding partnership between Shedd and Northwestern University’s McCormick School of Engineering. Each year, as part of their classwork, students are challenged to develop a product to meet the esoteric needs of Shedd’s Fishes, Marine Mammals, and Animal Health departments.

“Sometimes the projects are very specific, such as an anesthesia machine for fishes,” says Lisa Takaki, senior director of marine mammals, “but this year we simply asked for enrichment for the sea otters. The only specifications we gave them were that it had to be otter-proof and rust-proof, and they came back with about six concepts. We all agreed that the maze was an awesome idea. And the otters love it.”

“And it’s reinforcing for us to see them enjoy something that we’re also interacting with,” says Lana. “We can play too!”

Karen Furnweger, web editor