In Wellington, no one had seen the native North Island kākā parrot for a very long time.
Its distinctive rhythmic call and melodic whistles, once common in New Zealand's capital, were gone as well.
By the late 90s, urban development and introduced predators had decimated the population.
"It was completely extinct from the region around Wellington," Danielle Shanahan tells ABC RN's Sunday Extra.
So in 2000, when Jim Lynch opened Zealandia, an enormous urban eco-sanctuary designed to bring back the birds, most people were sceptical.
"It was a bit of a hare-brained idea," Dr Shanahan, now Zealandia's chief executive, says.
The 225-hectare property on the outskirts of the city is surrounded by a six-foot high predator exclusion fence that stretches almost nine kilometres. And right from the start a number of rare native species were reintroduced into the sanctuary. Among them were 14 North Island kākā.
What happened next stunned everyone, especially the neighbours.
'They hang off the clothesline'
Dinah Okeby and her husband Alec McLean live on a property that borders the sanctuary. When they bought it 25 years ago, the predator exclusion fence wasn't there and they would often take their kids for walks in the area.
"There was a lot of talk about [the sanctuary] and also quite a lot of scepticism about whether it would ever get off the ground because it was such a massive project," Ms Okeby says.
When the fence was finally built, the benefits weren't immediately clear.
"It was slightly annoying that you had this big fence go up, and then you had to pay to go in there," Ms Okeby says.
But then, she says, something "phenomenal" happened.
The birds came back to Wellington. And although the North Island kākā is still classified as 'at risk', the population is officially recovering.
Neither Ms Okeby nor Mr McLean remember the first time they saw a kākā on their property. Yet they're so common now, they say it's hard to believe they were once thought to be extinct in the area.
"They hang off the clothesline and guttering and look in the window," Mr McLean says.
"There's one our neighbours called Gavin, who's been around for a long time.
"We know his [ankle] bands. He's got a silver, a purple and a red."
The birds are very mischievous and have been caught stealing chips from their plates and stripping wood from their old deck handrail in the middle of the night.
It's not just Gavin and his mates who are back.
Since 2000, 18 native species, including birds, reptiles, amphibians and invertebrates, have been reintroduced into Zealandia.
For fellow Wellington resident Gary Lokum, the change in the local bird life has been stark. He moved overseas soon after the fence went up and returned two years ago to find the city changed.
"The spill-over from Zealandia to the rest of Wellington is amazing," he says.
The kākā weren't around when he left, but now he hears them every morning, flying over his house.
"There's something interesting going on in the Wellington psyche as well," Mr Lokum says.
"People are just getting right in behind [the sanctuary]."
Many people now set traps for predators outside the sanctuary fence, he says, which gives the wildlife that does spill over a better chance of surviving.
Mr Lokum is even more involved. He started volunteering at the sanctuary when he returned to Wellington, and he now works full-time looking after the sanctuary's infrastructure, particularly the fence.
'Throwing itself against the fence'
Dr Shanahan says when Mr Lynch first proposed a fully fenced predator-free urban forest, he had his work cut out for him.
A predator exclusion fence was a completely new concept and didn't exist anywhere in the world.
It needed to be high enough that cats couldn't jump it, slippery enough that possums couldn't climb it, and go deep enough that rabbits couldn't burrow underneath it.
In 1993, 22 conservation managers, scientists and engineers came together to assess several pre-existing fence designs.
The findings were grim. No pre-existing design was going to keep all the predators out. So, the group decided to design their own.
"They hired out a big warehouse and trialled prototypes with an animal on one side and something very tempting on the other," Dr Shanahan says. "They tried 1,000s and 1,000s of different modifications."
Until they figured it out.
Ms Okeby and Mr McLean say it became obvious quickly that the fence worked.
Soon after it went up, one of the neighbours told them about a possum seen trying to get into the sanctuary.
"It was throwing itself against the fence," Ms Okeby says.
"[The neighbour] watched it for a long time."
Dr Shanahan also says the rigorous testing has paid off.
"In my [six years] at Zealandia, we've had three weasel incursions, but other than that, we've done very well."
A blueprint for urban reforestation
Dr Shanahan says keeping predators out has also allowed native plants to flourish.
"About 150 years ago, there was nothing there," she says.
And when the fence went up, she says the area was filled with invasive weeds.
"We don't think of this often, but rats and mice take native seeds, and they eat them, and then they can't regenerate," she says.
Today, there are silver ferns, tree fuchsias and the climbing supplejack alongside numerous other species, many of which can't be found anywhere else in the world.
Recent research from the Journal of Animal Ecology has shown that restoring habitat is critical to re-establishing native forest bird communities in cities.
The flourishing native bird population in Wellington shows just what urban reforestation can do.
"We can reimagine what urban wildlife can be, and what can survive here," Dr Shanahan says.
So can Zealandia be replicated in other cities around the world?
Until recently, the fence design was under patent, but last year the sanctuary made it freely available under a creative commons license. The creators released a document detailing "the key design and maintenance considerations" of the fence.
And they hope the technology can be used elsewhere to achieve "significant conservation gains".
For the people of Wellington, they had to watch the kākā and other native species disappear before someone came up with a wild idea to save them. That is until they'd had enough, says Mr Lokum
"People just didn't want to lose any more," he says.
For Ms Okeby and Mr McLean, even the kākā's mischievous ways can't take away from the fact that they're thrilled to have the birds back.
"They just make you smile," Ms Okeby says.
Even if the couple did have to replace that wooden handrail with a metal one.
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