Orangutan's great escape causes zoo evacuation

(EPA)

A 137 pound orangutan with a history of mischief short-circuited an electric barrier, then built a makeshift ladder to escape from her enclosure, forcing Adelaide Zoo to be evacuated on one of its busiest days of the year.

Karta, a 27-year-old female, jammed a stick into wires connected to the barrier, then piled up shrubs, roots and debris to create a platform. Using it as a stepladder, she climbed up onto the concrete and glass wall surrounding her enclosure, where she was spotted by a member of the public who raised the alarm.

The zoo was cleared of Mother's Day crowds and vets stood by with tranquiliser guns, as a precaution. But, with freedom beckoning, Karta seemed to change her mind about the Great Escape, perching on the wall for about half an hour before climbing back into her enclosure.

Although she came within a few yards of visitors, one of the zoo's curators, Peter Whitehead, said the great ape had never displayed aggressive behaviour. "You're talking about an animal that's highly intelligent," he said. "We've had issues with her before in normal day- to-day operations where she tries to outsmart the keepers. She's an ingenious animal.

"So in this case she's decided to make a ladder and try to get out of her exhibit. I think when she actually got out and realised where she was, she's realised she shouldn't be there, so she's actually hung onto the wall and dropped back into the exhibit."

With Karta banished to her indoor night quarters for the rest of the day, zoo staff began a post-mortem into her Houdini-like exploits and said they would probably clear vegetation that could be used in a future escape attempt.

An 11-year-old boy, Ryan Johnston, told the Australian Broadcasting Corporation that he saw Karta scale the wall. "It was amazing how he did it, because he actually got a branch, pulled it over the electric fence and then got over," he said.

Mr Whitehead admitted it had been a “traumatic day” for many of the Mothers’ Day visitors. But he told the Adelaide Advertiser: "She's always been a bit mischievous. She likes being a bit inquisitive. Their nature is they will work on things and she just enjoys building things, unfortunately on the day and in the wrong area. There's no intent from this animal to get out and harm anybody."