The errant emperor penguin that showed up on a New Zealand beach a week ago appears to be feeling better after emergency treatment, New Zealand media report.

The lost Antarctic bird, the first seen in New Zealand in 43 years, had shown "feisty" behavior and eaten fish after veterinarians and a physician at the Wellington Zoo flushed more than 5 pounds of sand and sticks from its belly, TVNZ reported.

"Every day he survives, we have more confidence," Mauritz Basson, the zoo's general manager for operations, told TV One on Tuesday morning.

Although Basson used a masculine pronoun, the penguin's sex is not known.

"They do use ice to cool themselves down," Basson said by way of explaining the sand in the bird's belly. "I think he was probably trying to cool down sitting on Peka Peka Beach, which is slightly warmer than Antarctica this time of year.

"He consumed the sand, which didn't melt, didn't cool him down, so he ate it until he was full and he deteriorated quickly from there."

Experts are debating what to do next if the bird recovers. For now, it's being kept alone in a cold room with a blanket of ice on the floor. Keepers are reluctant to move it into a population for fear of spreading some undetected disease.

One such expert, John Cockrem, suggest releasing the penguin into the sea, point it toward Antarctica and let it find its own way home if it can.

"The bird had swum here naturally and in spring the juveniles would normally turn around and head south," he told TVNZ. "So if the bird is back in the water it can make its own way south as it would have normally done."