A leading Hawke's Bay conservation trust restoring 4,000 hectares of former pine forest to native bush has reported an unplanned benefit.
Kiwi from the neighbouring Maungataniwha Native Forest are starting to call the re-vegetating former pine block home. Breeding pairs have been observed migrating there from the old-growth forest.
The kiwi population on the Forest Lifeforce Restoration Trust's (FLRT) property in the Maungataniwha Native Forest became self-sustaining in 2017 after little more than a decade of enthusiastic conservation work. Now the population is beginning to spill over its border into the rejuvenating native bush of the former pine forest.
"I reckon they think they've found the promised land", said Barry Crene, the Forest Lifeforce Restoration Trust's resident kiwi whisperer.
"The undergrowth there is absolutely ideal for them - all that rotting pine slash and debris covered by the regenerating natives is great not only for their burrows but also as a food source."
Crene said there had always been kiwi on the rejuvenating land, even when it was under pine. But recent radio tracking of kiwi released into Maungataniwha Native Forest had revealed that some of the young birds were moving beyond its borders and into those blocks. There are five breeding pairs that he knows of, although tracks, sign and calls indicate others.
"It's all about territory," he said. "All of the flash housing in the old native forest is occupied so the youngsters are settling into the surrounding suburbs.
"In conservation terms this is a huge win and we couldn't be happier."
The Forest Lifeforce Restoration Trust has just completed an aerial spraying programme to kill naturally-seeded wilding pines on 630 hectares of the rejuvenating native bushland. Crene said the large area involved was to "make up for lost time" over the past two years, when Covid-19 lockdowns prevented their annual assault on wilding pines. Spraying did not affect kiwi or other birds and animals, he said.
Earlier this year the FLRT reported that a further 110 hectares had been cleared manually with funding from the Pan Pac Environmental Trust. Now more than a third of the area, about 1,500 hectares, can be described as clear of the exotic tree and regenerating with native species.
The 4,000 hectare conversion from pine to native bush is the FLRT's biggest and most expensive single undertaking. It uses a mix of aerial spraying and manual clearance methods to keep the wilding pines at bay.
The aim is to re-vegetate the area with indigenous forest. There is sufficient native species seed in the soil to enable natural regeneration but the major challenge, and cost, is the elimination of regenerating pine seedlings - which crowd out the slower growing native forest species.
It takes a decade to clear logged land of wilding pines completely and to get it to the point where it can be described as fully regenerated. During this time the land is nurtured, treated and monitored by the FLRT to ensure that the species they expect to appear do so.
Established in 2006 to provide direction and funding for the restoration of threatened species of fauna and flora in native forests within the central North Island, the FLRT also runs a series of native flora and fauna regeneration projects, in addition to the Maungataniwha Kiwi Project.
These include a drive to increase the wild-grown population of Kakabeak (Clianthus maximus), an extremely rare type of shrub.