The first chimes rang from afar. They were followed by a resonant harmony of high-pitched twangs, warbles and whines that raised the hackles on our necks. A pair was calling—due west across a deep gut—from the vicinity of Pa Ridge. There was only one thing for it. We hoisted our tape deck aloft on outstretched arm, “play” button depressed, and launched our own song skywards into the cool southerly. This failed to elicit a response, however, so we lowered the recorder and rubbed our hands warm again. We kept our ears turned in the direction of Pa Ridge, but except for the swishing of some swaying leafage overhead, silence prevailed.

Then an observant eye picked out a sharp speck hurtling from a treetop on the far side of the gut. This was tailed by a second: two dark arrows whizzing towards us across the intervening 100 m of airspace. These arrows rapidly metamorphosed into crow-sized birds crashing into the head of a tawa just down from where we stood. The kokako—for that’s what they were—didn’t stop there, but bounded, squirrel-like, up to the topmost branches, where they recommenced their melodious duet. We fumbled for our binoculars.

My daughter Hazel had had fleeting glimpses of wild kokako before, but nothing like this. She was helping out with the latest Kaharoa Kokako Trust census of territorial pairs in the Bay of Plenty forest of the same name. The morning light was exceptionally good, and Hazel’s vantage point, higher up the spur than mine, placed the two wattlebirds a little above head-height. She’d heard me waffle non-stop about these birds since 1989, the year both she and a ground-breaking kokako research-by-management (RbM) programme, in which Kaharoa Forest was to play an integral part, had hatched. Now, eyepieces wiped free of grit and focus adjusted, she was finally ingesting some of that elusive avian magic first-hand.

The higher kokako—the male—swayed from a branch, his glossy-black “robber mask” directed skywards as he threw his spooky calls out over the forest. From head to tail, apart from that heavy kohl and some delicate brown shading to wings, tail, rump and abdomen, his plumage was an elegant blue-grey. Curling under his throat from the base of his black bill were two daubs of vivid blue, the wattles—loose folds of skin—from which came the bird’s original Pakeha name: blue-wattled crow. His body was held aloft by legs that resembled a pair of black drinking straws, yet were more powerful than that description might suggest.

He fanned his tail feathers, then stretched out his wings, sweeping them up and back, repeatedly—ritualistically flapping them—while singing an onomatopoeic “koe-kah-koe”. Not only is such wing-clapping a visual display, it also, like an audio-locator beacon, helps the gregarious birds find each other in their densely forested habitat.

The lower kokako—the female—was smaller. Her colouration was identical to the male’s apart from more extensive brown tingeing, suggesting a younger bird. Her wattles were smaller, too. She rubbed her bill against a stout limb, then tilted her face upward, parrot-like. Barely two metres from her mate, she began plucking at toatoa leaves, pausing every so often to provide synchronised echo notes or otherwise complement his outpouring, hunching her back while her wattles vibrated with the effort of converting two lungfuls of antipodean air into one of the most exquisite melodies to be heard anywhere on Earth. Such birdsong—to a human ear—is a spiritual evocation: mournful, comforting, eerie, and more soulful than the purest New Orleans Dixieland.

We followed the pair for over 50 minutes, recording behavioural idio-syncrasies, noting diet and plotting the dimensions of their territory. Once we’d obtained the requisite data, we broke off and rejoined census co-ordinator Carmel Richardson. Carmel is a Hamurana local who has been involved with the kokako of Kaharoa since 1991, making her one of the country’s foremost field experts on this endemic species. She explained how kokako territories ranged in size from four to 12 ha, and that a single bird, not necessarily a pair, could hold a territory.