Ōpua Forest outside the trapping area, with large numbers of tree skeletons killed by introduced possums. Photo / Geoff Reid
Extensive trapping in part of Ōpua Forest has seen possum numbers slashed, but it's costly and Bay Bush Action is calling for cheaper and more effective approaches for forest protection.
Bay Bush Action, which looks after the forest and conducts pest control, has been focussing on a part of the forest for its possum trapping with amazing success.
While most of Ōpua forest has 94.7 per cent possum density, their trapping area has got the possum density down to just 4.7 per cent.
Brad Windust, Bay Bush Action volunteer and trustee who has been actively trapping in an area of the Ōpua Forest said that during the time of the trapping the group had seen the once gray skeleton canopy of this ''amazing forest'' come bursting back to life.
''(It's now) full of beautiful different shades of green and the huge Northern rātā that was saved in just the nick of time, is once again looking stunning with it's bright Christmas crimson flowers. When we first started we spent many long keen nights out kiwi listening, but sadly none were heard calling,'' Windust said.
''But our ongoing monitoring has shown they have been breeding up year after year and we now have 22 kiwi. And it's not only kiwi that have been breeding up in the safe zone. Weka once thought extinct here are becoming common now, bittern are back, and the mioweka and fern birds have made a dramatic comeback.
''What is really cool is seeing a lot more mokomoko, the stunning green geckos with their bright blue tongue. While the forest inside the trapping project is bursting with life it's a grim state of affairs in the remaining 2000ha that's had no pest control for nearly 30 years.
''As soon as you step outside the pest-controlled area the forest understorey is gone. It's like a herd of sheep has grazed it bare, but it's possums and rats snipping off the new seedlings as they pop up. The canopy has been stripped and huge tōtara hundreds of years old are severely munched or dead, turning white as dead wood is consumed by lichen.
''What's really sad is the sun now penetrates through the canopy. With no understorey, and very little leaf litter it dries the soil making it so hard that kiwi can't get their beaks in to feed." Lissy Fehnker-Heather, Forest & Bird regional manager said Bay Bush Action is helping bring back native species to Ōpua Forest but sadly the majority of Northland's native forests are dying without ongoing predator control.
''Forest & Bird is really concerned that the bulk of pest control falls to small community groups. Northland's ngahere and native wildlife need all hands on-deck, and way more funding. BBA are showing what can be achieved on a small scale, but Northlanders should be really worried at what's happening in their forests that don't have ongoing predator control, whether it's trapping, or 1080," Fehnker-Heather said.
''The key message from our perspective is that community trapping in Ōpua Forest is bringing back rare species - such as kiwi - but the majority of Northland's native forests are dying without ongoing predator control.''
She said the group's efforts to get possum density down to that level meant it was low enough to see native species such as kiwi, thrive in the trapping area.
''Despite this being an excellent result, trapping is a labour intensive and expensive form of predator control. Trapping is about $380/ha, whereas other options such as 1080 is $20/ha, and much less man power required.
''We need more inexpensive and effective approaches for forests such as Ōpua Forest. Particularly since Northland has around 20 really significant rain forests, and over the last 30 odd years very little or no pest control has been carried out in the majority of them,'' she said.