12,000 predators removed from Far North’s Ōpua Forest during autumn

Bay Bush Action trustee Brad Windust with the AT220 trap that is is making life tougher for pests in Ōpua Forest. The trust killed 12,000 rats, possums, stoats and feral cats removed over autumn

Pests are a major problem to our native forests, but in the Bay of Islands, a conservation group is making big inroads in Ōpua Forest, with 12,000 rats, possums, stoats and feral cats removed over autumn.

Bay Bush Action, which looks after the forest and has been running trapping operations for more than 14 years, is celebrating the removal of so many predators, giving the forest a chance to flourish. But the group acknowledges that it is a never-ending battle to keep back the tide of interlopers determined to devour the native flora and fauna.

Bay Bush Action volunteer Fleur Corbett said the autumn predator control operation was a huge success, with rats being the majority of the 12,000 pests removed.

“We’ve greatly built up our trap network, but we also had the opportunity to have some Jobs for Nature workers coming in to help with the bait stations.”

Some of the 2000-hectare Ōpua Forest.

The group has divided around 1150ha of the forest into grids and makes sure their traps are well spread so they cover as much of the forest as possible. One of the traps used is the AT220 trap that has a very impressive kill rate, with peanut butter-coated toxins almost irresistible to rats and possums in those and other traps.

Corbett said 1080 is used, but it is specifically targeted to traps, rather than an aerial drop, and this was one of the most effective ways to kill the predators.

The trust worked with neighbouring landowners to make sure there was no toxins getting on to their land, and that had been well received.

“We have a big buffer zone from where most people are ovine. It’s been a greatly positive experience doing all this work to help the forest heal and recover and thrive.”

Ōpua Forest is now chirping, buzzing, sprouting and flowering with the arrival of spring. Helped too by the removal of key predators following the toxin operation completed in May.

“We chose this timing as autumn is a crucial time in a stoat’s breeding cycle. We estimate we removed a further 12,000 rats, possums, stoats and feral cats, which in turn allows the native taonga to flourish. Some wonderful volunteers have been busy chopping ginger and other introduced pest plants along the Paihia School Rd Track, and another group of amazing wahine are helping to look after a forest block off Oromahoe Rd.

“Other volunteers have joined the Great Matuku Muster, a nationwide coordinated count of the critically endangered matuku-hūrepo (Australasian Bittern). We also teamed up with Focus Paihia and Bay Beach Clean for their recent working bee and with the Paihia Fire Brigade to help them celebrate 60 years of service. And as always, our team is busy trapping, maintaining traplines and cutting new ones.“

Tui feeding on kohekohe flowers. The timing of Bay Bush Action’s toxin operation in Ōpua Forest hugely knocked down possum numbers just ahead of the kohekohe flowering. Kohekohe are an important nectar source for birds such as tui

The trust will be bringing the AT220 self-resetting traps out of the forest over the next few months. The traps have been in there since 2021 so in the new year the trust will be looking for volunteers to help give them a full service.

“We’ll have a workstation set up at our conservation hub or you can take them home to work on if you prefer. We’d love you to join us for any of these activities, so email us at baybushaction@gmail.com if you’d like more info about volunteering."

Stoats and feral cats:

Before autumn’s toxin operation, Bay Bush Action trustee and volunteer Brad Windust and his conservation-certified dog Wero monitored a small area of the forest for stoat and feral cat scats. Wero indicated 44 stoat scats and 6 feral cat scats. They went back over the same area recently (post-operation) and found just 2 scats each for stoats and feral cats.

“This is a significant reduction in stoat scats and tells us all our hard mahi in autumn was well worth it.”

Rats and possums:

The autumn toxin operation reduced possums to 1.11% (bite mark index) and rats down to 1.67% (tracking tunnels). It recently did another monitor for rats and numbers have already come back up to 11%. This reinforces the importance of sustained control.

If we remove the pests from Ōpua Forest, and other ngahere, the natives, such as this greedy kereru, will do the rest

Stoat lines:

The trust now has five stoat trap lines running through the forest, 800 metres apart and up to 7.5km long. All of the lines are checked every month. Three of the lines have the traditional DOC200 double traps in a box, baited with rabbit or egg. The other two have larger run-through boxes, which have the same DOC200 traps but are not baited. These are intended to work on the animal’s behavioural instincts.

Annual toxin operation:

The next toxin operation is planned for autumn 2026 and the trust is looking for forest-fit volunteers to help keep bait station lines well-marked and clear of overgrown vegetation.

For more information or to help the Bay Bush Action team and its work go to www.baybushaction.org.nz.