Zookeepers are struggling to stay optimistic about the fate of a baby penguin believed to have been snatched from his parents, the zoo's manager said Wednesday.
Toga, a 3-month-old jackass penguin, was discovered missing Saturday from Amazon World on the Isle of Wight in southern England.
Zoo manager Kath Bright said veterinarians believed the bird probably would die of malnutrition by Thursday night if he wasn't reunited with his parents.
Zoo workers got a glimmer of hope when they received a report that a bird was found on a beach near the Isle of Wight, but it turned out to be a native guillemot, not a penguin.
"It got all our hopes up," she said. "Everybody's on a bit of a downer now, because we thought we had him back. ... Everybody's really tired, it's very emotional."
She said police were pursuing a lead on Toga's whereabouts but she did not know what it was. Hampshire police declined to comment.
With contributions from local businesses and well-wishers from around the world, the zoo has offered a 5,000 pound (US$8,750) reward for the penguin's safe return.
Bright said she believed the bird's disappearance was a real theft, not a hoax of any sort.
"If it's a joke it's a sick joke," she said. "They are putting this bird's life at risk," the AP quoted Bright as saying.