Director of Zealandia's centre for people and nature Dr Danielle Shanahan yesterday said police had been notified of the incident.
Today she told NZME that staff had set predator traps throughout the area and it was now "a bit of a waiting game" to see if they caught anything.
They were still uncertain whether any predators had made it through the hole, which was cut in a clean rectangle part way up the fence. The hole is large enough to let in introduced predators such as rats, cats and stoats.
"One of the things that we do is we put these tools out and we try and leave them a bit untouched for a few days, just so that if animals are out there they're not getting disturbed repeatedly," she said.
"They can smell us really well so they actually tend to avoid that."
Thankfully it was an easy job to patch the hole in the fence, she said.
"Interestingly, the perpetrator of this actually did a very tidy job with the hole. It's perfectly rectangle so we've been able to patch it with a larger piece of mesh, so that's something."
She was unsure why someone would do such a thing, but suspected it was somebody who "doesn't necessarily like Zealandia for any reason".
There are CCTV cameras along sections of the fence, but not the area where the hole was cut.
"We have nine kilometres of fence line. It's quite hard to really keep an eye on that."
Zealandia's best protection was alerts from members of the public who regularly walked or jogged the circuit by the perimeter, she said.
National's candidate for Wellington central Nicola Willis yesterday said she was "outraged", and that Zealandia was a "jewel in Wellington's crown".
"So many in our community have helped contribute to this local conservation effort ... to see some lowlife put all that at risk is just hugely disappointing.
"Mess with our fence and you're messing with everyone in Wellington."
One in five Wellingtonians trap pests in their own backyards, she said.
"[This is] a kick in the guts to all the Wellingtonians who are doing their best to conserve our native birds and I join them in condemning this behaviour.
"It's absolutely unacceptable and despicable behaviour."
