Volunteer groups linked to a Northland-wide kiwi protection initiative have trapped just under 400,000 pests since the project began seven years ago.
Kiwi Coast, which supports 155 conservation groups around Northland, has just released trapping figures for 2019 showing that 98,506 pest animals were caught last year — a sharp jump from 68,756 the year before.
The 2019 tally included 42,213 possums and 37,738 rats and mice. Volunteer groups also caught 2737 stoats, weasels and ferrets, with stoats in particular regarded as the single greatest threat to kiwi chicks.
The grand total for the past seven years is now 396,634 pests.
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Kiwi Coast co-ordinator Ngaire Sullivan said the tally increased every year as more people got involved in pest control to help Northland's native forests and wildlife, especially kiwi, could thrive.
"Close to 400,000 pests trapped over seven years has got to have made a tangible difference to Northland forests and native wildlife,'' she said.
''The groups and projects linked into Kiwi Coast are now working together over approximately 170,000ha. It's amazing what can be achieved when we all work together, but it all starts with just one person setting a possum trap in their back yard.''
On average more than 1800 introduced pests were now being cleared out of Northland every week, she added.
The number of ferrets caught each year was increasing as more groups got involved but was still markedly lower than other parts of the country.
''This is great news for our kiwi as ferrets can predate adult kiwi and can quickly devastate a local population,'' Sullivan said.
It was not clear if even the current high trapping numbers were making a dent in Northland's overall pest population, or if they were breeding and re-invading as fast as they could be trapped.
However, some groups were starting to report fewer pests than in previous years, especially in areas where projects had linked up to form continuous pest control operations covering 10,000 or more hectares.
Kiwi Coast Mid North co-ordinator Andrew Mentor said trapping was having a noticeable effect, for example in the Pungaere Rd area west of Kerikeri where predator control started in 2018.
Last year six local groups and the adjoining Puketi Forest Trust removed 14,499 pests.
When the area was surveyed in 2016 there were no kiwi present. A fresh survey using remote listening devices, completed just before the lockdown, detected a male and female.
It was likely they had moved in from Waipapa West or Kerikeri River, both of which had small remnant populations.
Kākā, a rare bush parrot, had also been spotted feeding on karaka trees in the area, Mentor said.
Kiwi Coast links about 150 entities including community-led conservation projects, iwi and hapu, schools, government agencies, forestry companies, non-governmental organisations, and local and regional government.
The aim is to create a ''kiwi corridor'' stretching more than 200km from Mangawhai to the Aupōuri Peninsula.
The total number of pests being eliminated in Northland is thought to be considerably higher because the Kiwi Coast figures don't include pests killed by toxins.
Most pest trapping is currently on hold because it is classed as non-essential under the Covid-19 alert level 4.