HONOLULU (AP) - Chimpanzees at the Honolulu Zoo were on lockdown until their keepers find out how one of the animals escaped.
Puiwa, a 15-year-old chimp, made a break for it Tuesday but didn't get far before being spotted outside the exhibit by a visitor, the Honolulu Star-Advertiser reported.
Zoo employees formed a perimeter around the chimp and visitors were ushered away. Puiwa was sedated using a tranquilizer gun and returned to the exhibit.
"To our knowledge, Puiwa never left the outer edge of the exhibit," zoo director Jeffrey Wilkinson said at a news conference.
The eight zoo chimps will stay in a pen near their sleeping quarters until an investigation determines how Puiwa split.
Chimpanzees at the zoo have escaped before, even though the exhibit is surrounded by a high wall.
In the late 1990s, chimps used an overhanging tree limb to leave from the same enclosure. Some of the zoo's current chimpanzees were involved in that caper.
"After that escape we've dramatically trimmed back or removed trees that could possibly allow for an escape," Wilkinson said.
Chimpanzees are incredibly athletic, he said.
"We're always trying to evolve and create better exhibits that really minimize the risk of escape with very clever animals," he said.