Firefighters on Chatham Island are battling to keep a 3000ha fire away from a conservation reserve.
Rural fire officer Craig Cottrill told Morning Report the fire was not yet contained.
"I would say the best way to describe it is almost contained," he said.
He said the wind conditions would be helpful today, with the northerly blowing the fire back on itself.
"The fire started sort of five or six kilometres off the road south of the Waitangi-Owenga road, and it's burnt through to the coast.
"Later on tomorrow the wind's going to shift off to the west so efforts today with the helicopter will be dampening down the front on the east side to keep it out of the Department of Conservation (DOC) scenic reserve we've got there."
Yesterday an @NZAirForce C-130 Hercules flew over the Chathams bushfire to help@FireEmergencyNZ map the scale of the blaze. This shows some of what they've been dealing with. #Force4NZ pic.twitter.com/BFo1zIfH7R— NZ Defence Force (@NZDefenceForce) February 3, 2018
"Having the two helicopters and the two specialist rural fire crews out there has really made a difference."
It was well away from people's homes, but less than 1km from a DOC reserve, he said.
"It's just significant biodiversity values in there. The ecology and the vegetation in there."
He said Moriori tree carvings were much further north.
Mr Cottrill said it could take as long as two weeks to completely douse the fire.