Paul Rush finds endangered native birds flying free with a little help from their friends.
Alone in a quiet forest glade, I watch mesmerised as two 'Clowns of the Forest' tussle with each other; boisterous bundles of brown feathers tumbling down through the foliage with a raucous chatter as if they are continuously on an adrenalin high.
The pair of North Island kaka flash their scarlet and orange underwing colouring, as they swing from tree to tree using their beaks and claws with equal dexterity.
They cling onto gnarly trunks, periodically stopping to use their bolt-cutter-like beaks to rip open bark and pry out hapless insects for a snack on the wing.
I'm watching the avian antics of the first native kaka parrots to be released from captivity into unfenced native bush.
At Pukaha Mount Bruce National Wildlife Centre, 30km north of Masterton in the Wairarapa, conservation staff are embarking on a bold experiment to raise the chicks of several endangered species to adulthood and then release them into their natural habitat in the surrounding podocarp forest.
It's an encouraging sign that the Department of Conservation's tireless efforts to save threatened avifauna on secure offshore islands and mainland communities is beginning to pay dividends. More successful releases at Pukaha will inspire other ecology groups to establish reserves without the need for expensive predator-proof fences.
Pukaha is the last remaining remnant of the 40 Mile Bush between Masterton and Norsewood, where early settlers experienced levels of morning chorus birdsong that were positively deafening.
Locals say that a teacher at Mount Bruce's first school dismissed her class one morning because she couldn't speak over the kokako choir outside.
This image of early New Zealand has always appealed to me. It was a land that drifted away from Gondwanaland 60 million years ago with no mammalian predators; an exclusive domain of birds that had little need to exert themselves by flying, so opted to stay on the ground and evolve into the flightless wonders we see today.
This would have remained a beautiful story about a land of birds with a finely balanced ecosystem, if human colonists had not introduced rats, stoats, possums, cats and dogs.
The result is our unenviable record of having the world's highest number of extinct bird species and the longest list of threatened species - our wonderful birdsong turned into a swansong.
It takes me some time to drag myself away from the crazy upside-down fussing, feuding and feeding antics of the kaka circus, in order to study another national treasure.
The North Island brown kiwi has now been provided with a $1.3 million home at Pukaha, which gives visitors a perfect behind-the-scenes view of the successful Operation Nest Egg breeding programme.
Through viewing windows I can see staff working in the nursery, where lines of incubators await the latest batch of kiwi chicks to emerge from their king-size eggs.
Thirty kiwi were transferred from Little Barrier Island to Pukaha in 2010, which gave the breeding programme a huge boost.
In the Kiwi House Theatre I learn more about pest control, forest restoration and kiwi translocations around the country.
I'm surprised to hear that a rare white kiwi called Manukura was born in May 2011, the offspring of brown kiwi from the island.
The Nocturnal Kiwi House has a group of foraging kiwi repeatedly prodding the leaf litter for elusive worms. The cute creatures occasionally make whistling and snuffling sounds as they potter around but seem quite unaware that there are human observers nearby.
I step out into the glare of daylight and follow the lookout track, listening intently for sounds in the bush.
A broad carpet of lichens and mosses covers the forest floor and an intricate latticework of supplejack and epiphytes entwines branches of the tall podocarp trees overhead.
I hear the faint haunting call of the shy kokako high up in the rimu canopy. The melodious flute-like note resembles the trill of a tui. But then a string of mews and clucks tells me it's a kokako.
Further along the track the clear, bell-like notes of a tui ring out in the still air, interspersed with the clicks, whistles, chuckles and chortles that form the parson bird's amazing repertoire.
It takes me a while to spot the tail-less rifleman, the white-ringed wax-eye and the normally inquisitive tomtit. The kakariki, stitchbird, grey warbler and whitehead are high in the forest canopy and elude me completely.
Not so the kereru, the noisy pigeon that startles me by flying straight over my head with a strong wing beat and heavy, crashing flight.
Arriving at the takahe enclosure I need a little patience to wait for one of the two resident flightless wonder birds to deign to show itself.
They are naturally shy birds. So shy in fact that they were thought to be extinct for 50 years until 1948, when it was revealed that 200 pairs inhabited Fiordland's Murchison Mountains.
I catch a brief glimpse of a takahe foraging amongst the tussock. He seems quite upbeat and cheery for a bird on the endangered list.
Pukaha Mount Bruce gives the hope for a brighter future.
New Zealand may once again be a land of birds, where, in every forest glade the bellbird chimes, the tui chortles, the kaka chatters and the big fat kereru coos.
It's a vision to hold on to and strive for.
Further information: See pukaha.org.nz.