For the next six weeks or so, Kali will be performing solo at the Buffalo Zoo’s polar bear exhibit.

That’s because his partner – the 1½-year-old old cub Luna – is nursing a broken leg after a roughly 14-foot fall into a dry moat Saturday afternoon.

Luna was resting comfortably Tuesday in the zoo’s veterinary hospital, eating and drinking well and responding positively to staff, according to Donna M. Fernandes, the zoo’s president and chief executive officer.

“She’s going to be fine,” said Fernandes. “She’s confined because we want to make sure she doesn’t put too much weight on her back foot.”

Luna fractured the tibia and fibula on her left rear leg above her ankle joint, according to the zoo. Fernandes said animal surgeons affixed a permanent plate to Luna’s leg bones.

“You can’t put a cast on a polar bear,” said Fernandes.

The incident occurred about 12:15 p.m. Saturday when Luna was walking around the 16-foot wall on the edge of the moat and, for an unknown reason, lost her footing and fell. The moat is what separates the animals from the general public.

Zoo officials investigated an anonymous tip that a child with a laser pointer could have been involved in distracting Luna, but that claim remained unfounded late Tuesday.

Meanwhile, the international animal rights organization People for the Ethical Treatment of Animals sharply criticized zoo management for allowing Luna to roam near the 16-foot drop-off. PETA is calling on the Buffalo Zoo to shut down its polar bear exhibit.

“It’s not appropriate,” said Brittany Peet, a Washington, D.C.-based counsel for PETA. “Polar bears are obviously not tigers and it’s not appropriate to have a polar bear in a tiger enclosure.”

But zoo officials said the fact that the polar bears are temporarily occupying space normally reserved for tigers didn’t factor into the cause of Luna’s fall.

“She’s walked around on that hundreds of times, and in the winter with layers of ice,” said Rachel Gottlieb, a zoo public affairs spokeswoman. “It is just a rare incident.”

Luna and Kali were sharing space in the tiger exhibit, alternating time slots with the huge cats.

The polar bears’ “Arctic Edge” exhibit is undergoing a $14 million upgrade at the Buffalo Zoo and is slated open to the public on schedule in fall 2015.

If PETA had its way, the zoo’s multimillion-dollar showcase exhibit would never open.

“Polar bears are one of the species that suffer the most in a zoo environment,” said Peet. “The Buffalo Zoo needs to transfer the polar bears to a more appropriate location where there are vast natural spaces in a consistently cool climate.”

Zoo officials dismissed the PETA charges. “They have their issues with zoos and they choose to ignore the positive things zoos do for animals,” Gottlieb said of PETA. “We always have the animals’ best interests in mind.”

Luna was in good hands after Saturday’s fall, and remains so, zoo officials said. After she fell, she was anesthetized by a dart and then transported her to the veterinary hospital at the zoo.

That’s where her leg was X-rayed by zoo veterinarian Dr. Kurt Volle, who confirmed the fractures. Zoo officials said a pair of board-certified veterinary surgeons from the Sheridan Animal Hospital attached a bone plate to stabilize the fracture on Sunday.

“We have very skilled veterinary surgeons locally,” Fernandes said. “They were immediately available.”

Luna is expected to remain out of the exhibit recuperating for at least the next six weeks.

“For us, it’s just about trying to limit her movement,” Fernandes said.

Fernandes said Luna is in good spirits and moving around in her quarantined location at the zoo.

At times, Luna even makes zoo officials concerned because she seems almost too happy. When Luna catches sight of her handler, Alice Rohauer, she stands up on her back legs.