Back in the Swim : Inhabitants of Polar Bear Plunge at San Diego Zoo Finally Take to New Home

Buzz and Neil are tussling. Chinook is sniffing and pawing a large ice block. Shakari is swimming underwater and--can it be?--appearing to mug for the camera.

In a few hours, youthful exuberance will give way to maturity, and Bonnie the matriarch will lumber into public view for a few star turns and then take a long nap.

The polar bears at the San Diego Zoo are doing what polar bears on display are supposed to do: By turns, look like playful bears and then ferocious, not-to-be-messed-with carnivores.

It wasn’t always so.

Last summer, the zoo’s polar bears were transferred to the new, much-ballyhooed $5-million Polar Bear Plunge and immediately became sick, strange and altogether disappointing. The bears were supposed to be the zoo’s headline attraction for the 1996 tourist season.

But not long after being moved from their 1920s-vintage grotto to more spacious digs with 130,000 gallons of chilled water, the bears were struck by a mysterious sickness and also took to neurotic pacing.

Zookeepers were forced to pull Bonnie, Chinook and Shakari off display, a public relations black eye for a zoo that, with much justification, touts itself as “the world famous San Diego Zoo.” Worse yet was the sudden death of 26-year-old Castor, Bonnie’s mate and one of the most beloved of the zoo’s 4,200 animals despite his notoriously cranky personality.

The unexpectedly sour beginning for the Polar Bear Plunge even prompted zoo officials to send a letter to the 220,000 members of the San Diego Zoological Society asking for their patience while animal behaviorists tried to make things right.

Now, as another summer season approaches, it appears that the zoo’s polar bears have made a comeback.

Bonnie still does some pacing--at 32, she is seen as too old to change completely--but the others have adapted well.

Buzz and Neil, neutered males, were imported in November from a zoo in Louisville, Ky., as playmates for the females Chinook and Shakari.

The four--ranging in age from 16 to 26 months and weighing from 301 to 446 pounds--play well together, save for an occasional nip. They bound into public view at 9 a.m. and frolic for several hours before slowing down and giving way to Bonnie around 2 p.m.

“We’ll see them playing occasionally with one dragging another around by the ear,” said Joan Simmerson, an animal behaviorist at the zoo. “That kind of aggression is very common in the wild and they need to learn how to withstand it.”

The bears’ diet has been changed to prevent overeating and the sloth factor that goes with it. And zookeepers are continuously tinkering with the bears’ open-air environment--providing enough change to be stimulating, not enough to be puzzling--to make the big mammals feel more comfortable.

Boulders and downed trees and bushes and kelp are rearranged. New smells are introduced. On a recent day, apple-scented aerosol was sprayed on the trees and bushes to give the bears a buzz.

“We need to stay a step ahead so they’re not bored,” said Gaylene Thomas, the zoo’s polar bear team leader. “The goal is to keep their environment a little bit dynamic.”

Castor, it turned out, died of cancer, not from the parasite in the fresh trout that felled Bonnie, Chinook and Shakari. These days the bears get less fresh fish, lest the parasite reappear.

As intelligent animals given in the wild to ranging up to 100 miles or more in a day, polar bears can get bored in captivity and begin pacing or acting aggressive.

The compulsive pacing (called “stereotypical” behavior) may have unnerved zoo patrons, but it was not a surprise to zoo experts. For example, Gus the polar bear at the Central Park Zoo in New York swam figure-eight laps for two years before his keepers were able to coax him out of it.

“Among zoo animals, polar bears are the most prone to stereotypic behavior,” said Judy Ball, general curator of the Los Angeles Zoo and a member of a bear advisory committee of the American Zoo and Aquarium Assn.

Michael Hutchins, director of conservation and science for the zoo and aquarium association, sees a cautionary tale in the story of the San Diego polar bears: If things can go wrong at the San Diego Zoo, with its long history of coping with behavioral problems, they can go wrong anywhere.

“Exhibits can be naturalistic and beautiful but the behavior of the animals is just as important as the setting,” Hutchins said. “All zoos need to focus more on behavioral history, not just veterinary care and nutrition.”

With 200 polar bears in 80 institutions in North America, the species is one of the more popular and sought-after attractions. Just last week, San Diego’s Sea World theme park took possession of three polar bears--Snowflake, Charly and Szenga--for its new Wild Arctic attraction. And the Los Angeles Zoo announced it is taking its lone polar bear, Sweetheart, off display for two months so that her exhibit can be renovated.

Even when problems arose, San Diego Zoo officials never lost heart that the polar bears would be stars. They have since given way to panda bears in much of the zoo’s advertising, but the polar bears still adorn a San Diego Zoo billboard along the westbound lanes of Interstate 8 just west of Yuma, Ariz.

It’s the route taken annually by thousands of zoo-bound tourists from Arizona--like the Jensen family--dad, mom, two kids--from Phoenix who visited the zoo last summer and were disappointed.

The family, back last week at the zoo’s Polar Bear Plunge, was pleasantly surprised.

“This is more like it,” said Bill Jensen, an accountant. “The polar bears are finally acting like polar bears.”