In 1770, in Queen Charlotte Sound, Joseph Banks, the naturalist on Captain Cook's first expedition, wrote of being woken by the birds' dawn chorus, "certainly the most melodious wild music I have ever heard, almost imitating small bells, but with the most tuneable silver sound imaginable".
After European settlement, this rapturous dawn chorus disappeared as native birds were predated by rats, cats, stoats, weasels and other introduced predators. But, now - on a bush track on Tiritiri Matangi - I experience the glory of the birdsong that so impressed Banks. The kokako is clearly the lead singer and in the choir we identify saddleback, squawking kakariki, bellbirds, tui, twittering fantails, the trill of tiny grey warblers and the occasional backup call of a cuckoo.
Tiritiri Matangi, a 75-minute ferry ride from central Auckland, is a brilliant conservation success story. The 220ha island was farmed until 1984 when it was bought by the Department of Conservation. All the introduced predators were eradicated and it became a scientific reserve and bird sanctuary open to the public. Over the years, volunteer group Supporters of Tiritiri Matangi have planted 283,000 trees to help with the regeneration of native bush.
Now 78 different species of bird can be seen on or around the island including 23 varieties of land-based native birds and numerous seabird species. Twelve rare birds have been reintroduced and are thriving, as are tuatara and endangered gecko and skinks.
We visit on a sunny Sunday and have a wish-list of star birds to see. We know we won't see night birds, such as kiwi and little blue penguins, but it's nice to know they are there, safely sleeping in their nest holes.
The flax is flowering and, standing still near a grove of it, we are amply rewarded with bird sightings. The list-ticking begins. Saddleback, shiny black with an orange feather saddle and pendulous orange wattles on either side of their beaks, swoop in to feed on flax flower nectar. They call each other making an almost a raspy sound, a bit like a squeaky wheel.
Tuis love the flax, too, as do bellbirds, which gather in a huddle and out-shout each other with heads held high, throats open, beaks wide - I can see their tiny pointy tongues - as they sing far louder than their littleness should allow.
Kakariki, red-crowned parakeets, are partial to flax nectar but they are shy and our presence causes them to take flight. Pairs of them screech at each other as they wing away in a flash of emerald and cochineal.
Fantails escort us as we tramp around Tiri's tracks, changing guard on the borders of their particular territories. They are hilariously cheeky, so close but never quite touching, flitting, fiddling, doing aeronautical stunts and tweeting to ensure we notice.
One little fellow does especially brave and dangerous tricks - he has only one feather left in his fan, an indicator, perhaps, that in the past he took one risk too many.
We stand on the Kawerau Track and listen to two kokako call each other in a strong pure sound stretching over many notes, like the chime of a temple bell or the ring of a piano tuner's fork. We are not lucky enough to see them, they are high in the canopy, but hearing them is a privilege.
Here, in this ancient bushy glade, there is a flurry of list-ticking: the North Island black robin hops about on a branch; stitchbirds (hihi) fly down from the canopy to inspect us; and tiny whiteheads chatter as they busy themselves in bushes.
On the other side of the island wood pigeons, the glamorous kereru - kings of the forest - whir overhead and a couple of these colourful creatures sit high in a puriri tree, keeping an eye on us as we sit eating our sandwiches. They, too, seem to enjoy the view.
The horizon on blue sea is edged by bumpy stretches of land, Moehau on the Coromandel Peninsula, Great Barrier, cloud-capped Little Barrier, Kawau and other islands of the north Hauraki Gulf. A container ship looks to be pulled by an invisible string across the picture, yachts in full sail beam-reach towards Great Barrier and near Tiri's rocky shores blokes in boats bob about at anchor, lazy-Sunday fishing.
The sun turns slices of sea into shimmering silver and, in the rippling glare, pohutukawa are silhouetted; strong branches of tortured shapes and knobbly roots holding tight to rocky ridges. Below us waves swish back and forth in Pohutukawa Cove and, for an unforgettable minute, a pair of tui pirouette together high above the sea.
Tiri's lighthouse, on the southern end of the island, has been guiding ships through the Gulf since 1865. It's fully automated, now, powered by solar panels and the Department of Conservation ranger lives in one of the original lighthouse cottages.
There is open grassland around the lighthouse and here flocks of pukeko feed. With fire-engine red legs, sturdy red wedge beaks and blue-black plumage, they look like prehistoric birds. Unlike fantails, they are shy and when we get close their tails start to flick, up down, up down, exposing their fluffy white bottoms. Then they stride off with a head-bobbing gait.
Takahe often graze with pukeko; they are bigger, sturdier and more green than blue, but are clearly close cousins. They are less suspicious than pukeko and we walk to within a metre or two of them. Their friendly nature and flightlessness have been their downfall, and they were thought to be extinct until they were found in the Murchison Valley in 1948. Takahe are still an endangered species with only about 200 left, 18 of which happily forage on Tiri's grasses and fern rhizomes.
Some takahe hang out around the lighthouse, and watching these great green-blue birds strutting about in front of a bright white 20.5m lighthouse is a bizarre, beautiful and uniquely Tiri experience.
Just before it's time to catch the ferry we see a fat tui sitting and singing on a nearby branch. He's black with rainbow shimmers, like petrol stains on a puddle. As he opens his beak wide, to project his tui song across the valley, I can see every feather of his white throat tuft as it bobs about in time to his tune. It's a fitting farewell song from a bird's paradise.
The 360 Discovery ferry travels to Tiritiri Matangi from Wendesday to Sunday and on public holidays. It departs Auckland at 9am or Gulf Harbour at 9.45am. Bookings are essential, phone 0800 360 3472.
Tea and coffee are available at the information centre by the lighthouse, but food is not sold on the island so you will need to pack your own lunch.