Pandemic postpones DoC predator control

The Conservation Department will halt operations to kill bird-eating pests during the four-week national shutdown. David Williams reports

Pest control operations to protect rare and vulnerable native species are about to cease.

The Department of Conservation will halt all biodiversity work during the upcoming four-week national shutdown, director-general Lou Sanson confirms.

“We debated that seriously but when we heard the Prime Minister [on Monday], and we understood the seriousness of the lockdown, the number one focus for New Zealand is to stop people moving, and that means all our biodiversity work stops, our construction work stops. About the only things we’ll be doing is the operation of sewerage schemes, search and rescue, and fire.”

(DoC acts as the local council, providing utilities like drinking water and sewerage schemes, in places like Aoraki/Mt Cook Village.)

Sanson says 1080 poison drops, and weed control operations, scheduled for the next four weeks have been deferred. The decision was made with deep regret, he says, adding: “We’re just completely backing the Prime Minister to do the job that needs to be done, to save the lives of hundreds of New Zealanders.”

On Sunday, after the country moved to alert level two, the department announced the closure of visitor centres and the cancellation of all hut and campsite bookings, including those for Great Walks up to June 30. Then, yesterday, DoC asked no one to use huts or campsites until further notice.

Sanson says hut wardens and visitor centre staff will be paid in full to the end of their contracts.

Countering the rat-aclysm

Pest control work has taken on huge importance over the past year or so to counter a surge of predators in native forests brought on by a so-called mega mast. That’s when climatic conditions cause heavy seed and fruit falls, something especially problematic in South Island native forests that are home to species sensitive to rats and stoats.

Those sensitive species include birds like mohua/yellowhead, kākāriki karaka/orange-fronted parakeet, and tuke/rock wren, as well as pekapeka/short- and long-tailed bats, and giant land snails and green geckos.

A widespread explosion of rodent numbers sparked the department’s biggest-ever predator control programme, Tiakina Ngā Manu, costing up to $41 million and featuring aerial 1080 drops covering some 900,000 hectares, as well as ground trapping.

(That increased from the initial budget of $30.5 million. However, some areas initially identified as top priority were cut and the area of some larger 1080 drops were shrunk to knock down exceptional predator numbers.)

Peter Morton, DoC’s predator control boss, said last December that a surge in rat numbers is a double whammy because it also boosts stoat numbers – with the latter showing up over summer and causing damage “over the first half of next year”.

Sanson says the department has had huge success with operations to protect the likes of takahē, kākāpō, kākāriki karaka, and whio/blue duck.

“We think we can hold these gains in four weeks,” he says. “We’ve been through all our threatened species work and we think they should be fine. But the biggest issue is during that [four-week] period pests getting back into islands or areas that we’ve got predator free.”

DoC staff won’t be checking rat traps or changing bait in the next four weeks. But Sanson says there’s nothing stopping volunteer groups doing that – if they live close by and practise physical distancing.

“This has been a massive job in closing our work down with virtually two days’ notice.” – Lou Sanson

It’s the biggest shutdown in DoC’s history.

Crews working to restore flood-damaged tracks in Milford Sound and the Hollyford Valley have been brought out. Almost all its nearly 3000 staff are working from home. “This has been a massive job in closing our work down with virtually two days’ notice,” Sanson says.

One difficulty has been staff working on offshore islands, like Raoul, in the Kermadecs, about 1000km northeast of mainland New Zealand, its northern-most territory, where six of its personnel are stationed. Sanson himself was meant to be on Raoul this week, but the Navy trip to take him there was cancelled because of the virus outbreak.

Other DoC staff are based in places like the Antipodes Islands, in the subantarctic, and Stephens Island, at the northernmost tip of the Marlborough Sounds.

“We will have a number of people left at offshore islands around New Zealand,” Sanson says. One advantage of being in such isolated places is they’re guaranteed to be free of coronavirus. “They’ll be fully able to go about their work.”

Sanson tries to see a silver lining. He says after the shutdown, DoC staff will have tested their ability to work in different, innovative ways.

“It might be we can work remotely in a connected environment,” he says. “If we can show that we can work this way, virtually, there are some significant gains to be made.”

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