First 1080 sites confirmed
The Department of Conservation’s ‘Battle for our Birds’ poison operations have been confirmed for Dart Valley, the Routeburn and Caples tracks, Iris Burn Valley, Waitutu and Waikaia.
The operation is a preemptive measure to curb a predicted predator plague in New Zealand native bush this year, after a prolific flowering of beech trees and high levels of seed production known as a beech mast.
DOC senior communications adviser Herb Christophers said most confirmed drops had been deferred until around September 1, and there was also a watch list of potential sites, including Hollyford Valley, Eglinton Valley, and the Dusky Sound Peninsulas.
“There’s a set of criteria that is helping to determine where we do what,” he said. “If a particular bird species was at risk they monitor the rat populations and determine a threshold.”
About 7000 rat monitoring tunnels and 400 seed trays across the country had been observed regularly since November, with a strategic check in May to determine crucial sites for 1080, and another planned for next month which would give a “definitive idea of what we’re going to do”, Mr Christophers said.
The first shipment of 1080 bait pellets was loaded into Te Anau last week, not yet earmarked for specific sites, he said.
“It takes a certain time to get the bait manufactured,” he said. “There are a couple of trucks a week coming out of Whanganui.”
Some confirmed drop sites would receive bait coated in deer repellent, which was done in collaboration with the Deerstalkers Association, as it was not accommodated in DOC’s budget, Mr Christophers said.
“You have to anticipate that you’re going to be using a deer repellent bait,” he said. “In this case, there are only two sites: Cobb, near Kahurangi [National Park], and Waikaia.”
For the most part the beech mast had been most concentrated in the northwest South Island, Mr Christophers said.
While any 1080 drops would have an impact on hunters, the deerstalkers understood and appreciated the necessity of protecting native birds, Mr Christophers said.
“This is a one-in-15-year operation,” he said. “As it is, mohua are hanging on in pockets in small places around the South Island.”
Dealing with predator species that could flourish so easily meant that it was difficult to exaggerate the risks of complacency in a beech mast situation, he said.
“Rats are extremely adaptable, so we’ve got to be one step ahead of them.”