STEEL fences at the new gorilla enclosure at Werribee Zoo will be reinforced after professional climbers yesterday managed to breach the perimeter in seconds.

Professional abseilers were brought in to test that the huge enclosure is escape-proof, before three male gorillas arrive over the next fortnight.

Award-winning climber James Kassay, of Bayside Indoor Rock Climbing, proved the area was penetrable after clawing under the fence and then scampering along the wall to reach an area the gorillas should not access.

The climbing test showed that no stone is being left unturned to make sure the gorillas are safe and comfortable in their new 6000sq m bachelor pad.

Zoo favourite Yakini has previously proved himself a Houdini, escaping from his enclosure at Melbourne Zoo two years ago by grabbing a low-hanging palm frond to climb over a wall.

He went walkabout for 20 minutes, looking at other animals, before keepers lured him back.

This time, there will be no monkeying around when Yakini joins mates Motaba and Ganyeka in their specially designed and lavishly decked out exhibit.

"They have very long arms and big hands and with their strength, we have to make sure they won't be able to get out at any point," said Kylie Lihou, Werribee Zoo's life science supervisor.

Three keepers who will be in charge of the trio have spent months getting to know their charges at Melbourne Zoo.

"(The gorillas) have their own climate-controlled gorilla house and a splash pool," Ms Lihou said.

"And with Yakini and Ganyeka turning into silverbacks, they will need their own space and area to get away on their own when they want," she said.

"Already, Yakini and Motaba are having displays of aggression."

ryankel@heraldsun.com.au

Originally published as Rock climber busts new gorilla enclosure