For humans at Minnesota’s two largest zoos, the corona­virus means shuttered front doors. For the animals, it means a lack of curious faces on the other side of the glass.

So staffers at both St. Paul’s Como Zoo and the Minnesota Zoo in Apple Valley are employing creative strategies — from car rides to yoga demonstrations — to delight and stimulate their animals in the absence of visitor interaction.

“The animals are [used to] having a constant influx of people watching them, looking at them,” said Allison Jungheim, Como’s senior zookeeper. “To have it all of a sudden be absolutely nothing has been a bit of a shock to some of them.”

Zookeepers have come up with solutions. At Como, they’re keeping penguins mentally stimulated by letting them waddle through empty public areas; a visit to the big cats is in the works.

Como staffers also are doing yoga every day in front of the gorillas, not only for their own relief but to pique the primates’ curiosity.

Some animals, such as the gibbon apes, have noticed they’re not getting visitors and becoming suspicious, said Terah Grace, assistant curator of behavioral husbandry at the Minnesota Zoo.

And the otters and penguins, who sometimes play games with visitors, have no kids to chase around.

“Definitely some of them are missing that,” she said. “It’s an enriching part of their day.”

Staffers at the Minnesota Zoo said it’s especially important to keep the Animal Ambassadors, which travel to schools and interact with zoo visitors outside their cages, accustomed to their training routines. So they’re packing up their parrots and driving them around the zoo campus to look out the window and listen to tunes on the radio as they usually do while on the road.

“We have a unique challenge because we still have to maintain all of those behaviors,” said Trinity Leiser, the Minnesota Zoo’s outreach programs supervisor, adding that otherwise the animals will need some retraining when the zoo reopens.

The extended shutdowns are unprecedented for the animals, since Como Zoo is a 365-day-a-year operation and the Minnesota Zoo is closed only on Thanksgiving and Christmas.

But staffers at both zoos said that little has changed for them. The animals still need to be fed and cared for.

“Right now, the zoo belongs to the animals,” said Leiser. “We’re just trying to keep things as normal as possible.”

Like the Twin Cities zoos, most zoos today incorporate “enrichment,” or extra stimulation, into animals’ lives. Captive animals generally lack the opportunity to affect their surroundings the way their wild counterparts can, said Tiffany Wolf, a University of Minnesota veterinary professor.

“Enrichment is an opportunity to provide them some physiological and psychological well-being in an environment that is not the environment they’ve evolved in,” Wolf said.

Enrichment can include different foods, sensory experiences or activities. A primate might solve a puzzle to get a treat, while a bear might receive a pumpkin to break open, she said.

If animals don’t get enough mental stimulation, they can resort to threatening behavior, self-mutilation or abnormal behaviors like pacing, she said.

Animals are different in terms of how much they enjoy human interaction, Wolf said. Some species are fearful of people and thrive when they’re not around, while others have strong relationships with only their caretakers. A third group likes human interaction, generalizing that people are good because of their positive relationships with zoo staff.

At Como, for instance, orangutans seem to miss people a lot, while the lesser kudu, an antelope species, are more comfortable with no one around, Jungheim said.

Animals that like people benefit the most from extra enrichment when the zoo is closed, Wolf said. Zookeepers are the best judge of their needs, she said.

At the Minnesota Zoo, zookeepers are increasing the number of items they place in animal habitats and offering them at different times of day, Grace said. That includes plastic rocking horses for the Japanese snow monkeys, feeder balls for the tigers or logs with insects for the anteaters to dig out.

Many animals are exploring new areas. A beaver recently visited the brown bears, for instance, and porcupines are going on longer jaunts, she said.

A normally reclusive African gray parrot “loves going out and walking around on the rocks with the penguins,” Leiser said, while other exotic birds enjoy spying on the fish and seals. The resident red-footed tortoise has been walking farther to compensate for the human contact she relishes, she said.

“We’re just trying to remember to give her lots of love because she definitely seeks out attention from people,” Leiser said.

Zookeepers said that while it’s disappointing to be closed, they’re looking for the silver lining. At Como, they have extra hours to clean exhibit spaces and pools and do yardwork, which usually must be done by 10 a.m.

There’s more time to train the animals, from big cats and sea lions to a sloth that is reluctant to climb down her tree to meet visitors, Jungheim said.

Zookeepers also have more time to sit and play with animals, giving them attention and building trust, Leiser said. She citied the zookeepers’ growing bond with a Flemish giant rabbit.

The added time with animals is therapeutic for staff, she said.

“It’s just such a stressful time for so many people,” Leiser said. “We’re really lucky, I think, to go into a space where we can interact with animals.”