Rats are on the run in leafy east Auckland, with hundreds of households tooled up and hunting the furry vermin.
And the evidence is emerging that it is having a positive effect on native bird numbers there and in other places around the region where communities have been inspired to help get rid of animal pests.
Kākā and bellbirds are rearing chicks at several places in the Auckland region and kākāriki at one site in Birkenhead.
The Eastern Bays Songbird Project in east Auckland is one of more than a thousand community or school schemes around New Zealand trying to reduce the number of rats and other animal pests, including possums and in some areas stoats too.
Aucklanders have been reporting an explosion in the number of rats and conservationists have pointed to a heavy fruiting season of trees - a "mega mast" - as the cause.
Rats said to be as big as cats were reported scurrying around Titirangi village in West Auckland last week.
Today, Kit Parkinson, chairman of the Ōrākei Local Board, which helps fund rat-trapping, told of large numbers of rats plaguing the city's eastern waterfront.
"We've had a huge inundation of rats in Selwyn Reserve at Mission Bay. It's been reported by dozens of constituents plus businesspeople down there. Our contractors are reporting it as well."
Contractors were using bait and traps to control the vermin.
Parkinson has a trap in the backyard of his home, near Kohimarama's Mary Atkin Reserve, which had caught a number of rats, but not as many as the cat.
The aim of the Eastern Bays Songbird Project, funded mainly by Parkinson's board, Auckland Council, Kiwibank, Predator Free NZ Trust and the Department of Conservation, is to have traps in a quarter of east Auckland's 30,000 backyards.
Since it began in late 2017 it had lent out 1083 rat traps and 189 possum traps, said project manager Kerry Lukies.
Most of the rat traps were at people's homes, but there were also many on Ngāti Whātua Ōrākei land.
The predator control group asked trap users to report catches and the tally to date was 687 rats and 267 possums.
Predator Free NZ lists 70 pest control groups in Auckland and 56 in Wellington.
Brett Butland, the project director of council-run Pest Free Auckland, said there were more than 1700 community or school groups in the Auckland region involved in controlling pest animals or plants.
He said predator control had led to the return of some native bird species to mainland Auckland and in some cases even nesting and fledgling. Species reported to have nested and fledged chicks were bellbirds at Whangaparaoa Peninsula and Birkenhead, kākāriki at a bush reserve in Birkenhead, and kākā at Northcote, Kohimarama and Mission Bay.
"From around the region clearly the effects of predator control are starting to occur. This is about restoring our native biodiversity, doing the pest control and what's required to get the birds and invertebrates to come back."