“The worst thing that has happened in Lemon Tree Passage is Colorbond fences,” Hunter Koala Preservation Society past vice president Wayne Black said.

“I’ve only ever seen them get about half way up.”

Koalas tend to move from tree to tree, across the ground, via line-of-sight.

Mr Black said those fences were particularly troublesome for the movement of koalas.

“They’ve got no problems getting up a paling fence or a mesh fence for that matter,” he said.

“But people can lay a ferry rope over their Colorbond fence, they’ll climb that. Maybe one in the pool too.”