(CNN) -- An emperor penguin discovered thousands of kilometers away from Antarctica with a bellyful of sand is recovering after an endoscopy Monday, a New Zealand zoo official said.
The procedure removed "much of the gunk that was in his stomach," including "rocks, sticks and stones," said Dr. Lisa Argilla, manager of veterinary science at Wellington Zoo, where the bird was taken for treatment. The penguin has also been passing sand.
The penguin -- whose gender is unknown pending DNA test results -- stunned passers-by last week when it showed up at a beach north of Wellington.
"This is only the second time an emperor penguin has been seen in New Zealand," said Kate Baker, spokeswoman for the Wellington Zoo.
Even more surprising was what the zoo found inside the penguin -- enough sand to fill its stomach and esophagus.
"In Antarctica, they normally eat ice to cool down and to hydrate," Baker said. It's possible the bird mistook or tried to substitute the sand for snow or ice.
It's unclear why the penguin apparently swam more than 3,000 kilometers (1,864 miles) from Antarctica. Argilla said the bird might have gotten lost in a current, or perhaps its internal radar went awry.
New Zealanders have dubbed the penguin "Happy Feet," a reference to the 2006 animated movie about emperor penguins. But those at the Wellington Zoo are steering clear of giving the bird a name.
"We get very fond of our patients. If you start naming them, it's really hard if the worst were to happen," Argilla said.
The bird has undergone multiple stomach flushes, but getting all the sand out remains a challenge, Argilla said.
"Having sand in your stomach is very serious," she said. "It can cause a rupture, that's my main concern. ... I would assume the sand has abraded the stomach lining."
Hundreds of zoo visitors watched the endoscopy Monday and heard live commentary during the procedure.
Argilla said emperor penguins normally eat rocks to help them digest, "but he went way overboard. I think he mistook it for snow to cool him off."
The zoo currently has four little blue penguins, which are native in New Zealand, Baker said. All have been rehabilitated; one is missing an eye, and one is missing a flipper.
But taking care of an emperor penguin is an entirely different story. The bird's temporary quarters include air conditioning set as cold as possible and shaved ice to help the emperor stay cool.
Keeping the bird at the zoo permanently isn't feasible. Not only would building an exhibit to house an emperor penguin be extremely expensive, the wild bird is "a very social animal. We would need more (penguins)," Argilla said.
Argilla said the top priority is helping the bird recover. If all goes well, representatives from the Wellington zoo, New Zealand's Department of Conservation and other experts will decide where the penguin should go. Argilla said she hopes the bird will be able to return to the wild.
In the meantime, the penguin has garnered widespread attention and sympathy.
"I think people have a real soft spot for penguins," Argilla said. "Everyone feels really sorry for him. He's just so lost."
CNN's Dana Ford contributed to this report.