While the use of 1080 to control possums may not please everyone, it is putting a smile on the face of staff in the Department of Conservation’s Wanganui conservancy.
Several of the conservancy’s larger possum-control areas have been monitored over recent months, and according to DoC programme manager Paul Prip, “the recovery of the forest canopy has been spectacular.”
The monitoring occurred in areas in Taranaki and Wanganui which receive treatment with 1080 baits on a seven- to eight-year cycle. Thirty to 40 sites in each area were selected randomly and viewed from a helicopter hovering above the forest. Pre-selected tree species were identified and scored according to the density of their foliage.
“The results from Whitecliffs forest, in Taranaki, were the most impressive, with virtually no possum browse or impacts being seen two years after the last possum control operation,” says Prip. “In fact, I struggled to see any sign of possum damage.”
In Whanganui National Park, Prip says the Matemateaonga area is showing signs of recovery 14 months after possum control treatment, with visible fresh undamaged growth on rata and totara. A second area is showing little sign of new possum damage, even though treatment occurred nearly four years ago.
A third area, last treated seven years ago and due for a poison drop in a year or so, shows possum damage becoming more widespread, but remaining at a low level.
A lush forest canopy is not the only result of the pest-control operation. Sightings of kereru (native pigeon) and other native birds have increased. And where goat control has also been occurring, as it has in Whitecliffs, improvements on the forest floor match the recovery of the canopy.