Bay Bust Action trustee Brad Windust and his conservation dog Wero. Photo / supplied
The severe rain that drenched Northland was disastrous for many people, but it was “absolute pure gold” for Ōpua Forest, a conservationist says.
Brad Windust, a trustee of Bay Bust Action, which has been predator-proofing the forest for the past 15 years, said the slow, warm deluge arrived at exactly the right moment.
Windust said the forest received a gentle 20mm of rain the first day, 90mm the next, followed by steady, windless rain, which brought the week’s total to between 160mm and 250mm – conditions he described as ideal.
The positive effect on the trees was immediate, with new growth appearing almost instantly, Windust said. The rain meant taraire trees would hold their berries through summer and ripen in mid‑winter, creating a bumper extended breeding season for kererū (wood pigeon).
“The soft rain also pushes beetle larvae and worms closer to the surface, so the kiwi can feed and keep breeding as well,” Windust said.
Cicadas kept singing throughout the rain. After spending seven years underground, they have just two weeks above it to sing and find a mate, and the weather was not going to stop them, Windust said. Once the rain cleared, insects emerged in abundance, providing a feast for birds like tomtits, kingfishers and fantails.
Years ago, the Ōpua forest was set aside for nature to prevent land failures and silt from washing into the Bay of Islands – and it’s doing its job, Windust said.
The forest contains many spectacular wetlands, including one of the top 10 remaining in the Far North. “It’s like a huge sponge, catching most of the water coming off the forest and slowly releasing it, clean, out into the Waitangi River and into the Bay of Islands.”
“The great thing about this rain is it comes at a critical time, just as German wasps were starting to build nests," Windust said. ”This weather event will have killed thousands of nests, meaning we likely won’t have a big German wasp year in the forest. That’s a massive benefit to the insects they prey on, because insects are the backbone of the forest ecosystem."
Windust said Bay Bush Action was proud of the forest’s current condition. The group’s achievements to date included trapping:
“The difference in the forest is incredible. From [increased] kiwi and weka [numbers], to carpets of seedlings coming up on the forest floor,” he said.
2025 was a particularly significant year for the group, Windust said.
“We knocked possums and rats down to just 1% over the whole forest! And made a massive impact on the stoat and possum numbers.”
During the year, the group installed two major new stoat trap lines using the latest technology, secured funding to begin a new bait station grid, and started relocating 533 AT220 automatic traps to form a protective perimeter around the forest’s outer edge. Monthly servicing of all traps continued across the entire project area.
Beyond pest control, Windust said volunteers expanded their work into restoration, education and community engagement. A dedicated weeders group cleaned up the forest entrance, large areas of woolly nightshade were cleared from the Kaipātiki wetland, and a women’s forest group began meeting weekly to maintain bait station lines.
Bay Bush Action also established forest tours for cruise-ship passengers, securing an ongoing source of funding, and was gifted an electric car for its volunteers’ use.
A partnership with Ngāti Kawa and Ngāti Rāhiri enabled the installation of new bird information boards along the foreshore. During the year, the group also discovered a previously unrecorded forest gecko species, Windust said.
Sarah Curtis is a news reporter for the Northern Advocate, covering a wide range of issues. She has 20 years’ experience in journalism, mostly as a court reporter in Gisborne and on the East Coast