New aerial monitoring has documented extensive possum damage in a rare native forest in New Zealand’s upper Wilberforce and Mathias valleys. The Department of Conservation says approximately half of the vulnerable mountain tōtara and kaikawaka, or mountain cedar, trees assessed in the Wilberforce forest have been affected.
Possums browse foliage, damage crowns and suppress regeneration. DOC warns that continued pressure could push this nationally significant forest type toward collapse. The agency plans an aerial operation using biodegradable 1080 cereal bait during the first suitable weather window between September 14 and November 30. The operation is also intended to reduce rats and stoats.
DOC says it consulted hunters and neighboring land users, agreed to use deer repellent and adjusted timing to avoid grazing and peak recreation periods. A community-led ground-control project is also planned in part of the forest.
The photographs make the scale of canopy loss visible, but the longer test will be whether repeated monitoring shows recovery after pest control—and whether protection can be sustained before numbers build again.