Stardom Eludes Star-Crossed Polar Bears

SAN DIEGO —  Bonnie was pacing again Monday. She’s still a magnificent 480-pound carnivore, but she was supposed to be a lot more.

This was to be the summer for the two adult polar bears and two polar bear cubs at the San Diego Zoo to become headliners.

But it has not turned out that way. Sickness, death, odd behavior and a certain mammalian stubbornness have turned the new $5-million Polar Bear Plunge into the most ill-starred venture in the history of this world-famous zoo.

In June, amid much hoopla, the zoo opened the plunge, a 5,500-square-foot enclosure touted as a “veritable arctic kingdom,” with a waterfall, a stream, plenty of room to roam, and a 130,000-gallon, 12-foot-deep tank for the bears to indulge their web-footed affinity for swimming.

Visitors would have a nose-to-nose view of the white-coated bears through an acrylic window above and below the waterline.

No more the old-fashioned grotto where all the bears could do was wade and roll around a bit. No more the green tinge to their fur caused by algae in water that was too warm.

A massive advertising campaign was designed to make the polar bears into stars.

Freeway billboards show a polar bear in a full-out horizontal dive worthy of an Olympic swimmer. Television commercials with underwater photography show one of the massive creatures plunging gracefully into the water (the commercial was shot at the Toledo zoo, not San Diego).

Within weeks of the grand opening, three of the bears were laid up with a mysterious intestinal ailment. Bonnie and the two cubs, Chinook and Shakari, began compulsive pacing behavior. None of the animals has learned to make entrances and exits on cue.

Zoo visitors expecting to see polar bears swimming, diving and frolicking have had to settle a good deal of the time for polar bears lying down or pacing.

And then Friday night, 26-year-old Castor, one of the zoo’s most beloved animals, died just when zoologists thought he had shaken the rare parasite that he may have picked up eating fresh trout.

“It’s always hard to lose an animal,” Dr. Donald L. Janssen, the zoo’s director of veterinary medicine, said. “But we still think in the long term, this is a much better place for the polar bears to be” than the old grotto, he said.

In early August, Castor, Bonnie and Shakari were hit by the same intestinal distress. Zookeepers promptly pulled them out of the exhibit and begin a rigorous treatment of antibiotics.

A preliminary post-mortem showed that Castor died of pneumonia and liver disease probably brought on by a rickettsia bacterial organism found in trout.

Fresh trout were a plunge innovation and considered a double treat: fun for the bears to snatch, and a delight for visitors to watch. Now the trout have been pulled from the 55-degree water and the bears switched to frozen fish.

“We have long been critical of polar bears in captivity,” said Wayne Pacelle, vice president of the Washington-based Humane Society of the United States. “Polar bears in captivity are a square peg in a round hole. Zoos cannot reproduce the arctic environment, and the animals suffer.”

Zoo officials respond that San Diego has a long history of keeping polar bears in good health and, further, that polar bears are enormously helpful in engendering public concern for wild animals. Polar bears are what zookeepers call “charismatic megavertebrates.”

“Bonnie is a flagship species,” said Gary Priest, the zoo’s top animal behaviorist. “She represents every other animal in the tundra. She is the arctic, just like the elephant is Africa.”

No one is sure why Bonnie, who is 30, and the two cubs, which were brought to the zoo from Manitoba after being orphaned in the wild, have taken to pacing. Or whether the behavior is normal or neurotic.

The zoo remains committed to the Polar Bear Plunge. Two young males are being acquired from the Louisville zoo as possible mates for Shakari and Chinook, both females.

A zoo employee is stationed at the plunge to answer questions. The most commonly asked question is whether the bears are pacing because they are unhappy.

Priest said polar bears have been seen exhibiting similar “stereotypical behavior” in the wild, possibly to burn off calories. Still, polar bears in zoos have been known to engage in endless repetitions in response to changes in their environment.

Gus, a polar bear in the Central Park Zoo in New York, swam figure-eight laps for nearly two years before behaviorists changed his environment enough that he stopped. On that theory, Priest is experimenting with different sights and smells and obstacles in the Polar Bear Plunge.

Zoo officials studied polar bear enclosures at other zoos and thought that they had anticipated potential problems before opening the Polar Bear Plunge. That has led to a certain chagrin that the first months have been so rocky.

“To a polar bear, this should be like heaven on Earth,” Janssen said.