reports the bird likely escaped its enclosure by scaling a rocky area near the walls of the harbor-front aquarium, which is home to 134 other penguins.
, a spokesman for the aquarium, told reporters, "We first noticed the penguin might have fled when the director of a neighboring zoo emailed us Sunday with a photo."
Sugino added that attempts to recapture the bird have been unsuccessful. "It's a bit of a struggle to catch it when it is swimming because it swims at a tremendous speed. We are hoping to catch it when it climbs up on land to sleep."
Humboldt penguins are native to South America, and are classified as a threatened species.
Anyone who spots the penguin is asked not to chase it
. Instead, contact the sea park at (03) 3869-5153.