Blue duck on a long dive to oblivion

The numbers of whio left could be as low as 500 pairs. Picture / Alan Gibson

Tyronne "Bubs" Smith looks every inch the back-country man: long, thin legs encased in black wetsuit and leggings, a pair of old hiking boots on his feet as he stands in the chilly waters of the Mangatepopo River.

His days are spent on the trail of one of New Zealand's most endangered birds, the blue duck or whio, that live on the turbulent rivers flowing down from the mountains through the North Island's central plateau.

He knows where to find them in the early-morning chill as they dip and dive among the grey boulders and rapids, or hide away in the afternoon in secluded nests in caves or under logs near the riverbank.

From the Department of Conservation office in Turangi, we have driven for about half an hour to the southwest, Mt Ruapehu's snow-covered slopes glinting white in the morning sun.

The hundreds of hectares of rugged country around Tongariro National Park are a last stronghold for these birds, named by Maori after the male's high-pitched "whio, whio" whistle.

It takes an impressive amount of organisation by DoC staff from the Taupo/Turangi area office to get us to the banks of the Mangatepopo.

Three different 4WD vehicles are necessary for the journey. The final leg involves a cling-on-for-dear-life quadbike ride over pitted forestry tracks with fallen trees and overhanging cutty-grass. Then it's a short hike to a rope at the top of a steep bank, flailing in mid-air as you try to get a foothold.

Apparently this is an easy trip and we're saved another 1km hike upriver because Smith has gone ahead and herded a whio family back down towards us.

The ducks arrive on cue, bobbing effortlessly downstream or padding over the grey boulders, two adults herding six chicks.

This spot is close to this whio pair's territory and they won't go any further.

Whio have no close relative anywhere in the world and are high on DoC's threatened list. Just over two years ago, they jumped from vulnerable to endangered on the World Conservation Union's "red list" of threatened species.

In a decade, population estimates have plunged. A report published by DoC last July called a 1994 population figure of between 2000 to 3000 birds "a dangerous over-estimate". The number could be as low as 500 pairs, it said.

Outside areas targeted for active predator control, DoC accepts that local bird colonies are dying out in both the North and South Islands.

Stoats are a prime suspect in the whio's decline. The forest's serial killer attacks chicks and adults. Male ducks will put up a fight but have no chance, Smith says.

Like kiwi, whio establish a territory by fighting off other whio. The birds are monogamous and one pair will occupy the same stretch of river year after year.

As with other fragmented and struggling bird populations, numbers of single male birds are high. In this key Whanganui/Whakapapa/Mangatepopo area in Tongariro Forest, Smith is tracking 33 pairs and 22 single birds - in a healthy population the ratio of pairs would be higher.

Males can live to around 12 years. The oldest recorded whio was 13.

Smith has a soft spot for one old duck he has nicknamed "Koro Green", koro for grandfather and Green after local DoC boss Paul Green.

Smith was mystified at first when every female duck passed through the bird's territory without a backward glance. Then he realised it was probably because of his age.

"He's a bit like me. I get chicks going past me in a bar on a Saturday night," he jokes.

Smith has a seven-month contract with DoC, and is part of a new offensive in the fight to save the blue duck.

The campaign has been launched by DoC and is financed largely by the power company Genesis through the Blue Duck Conservation Charitable Trust.

The six-year plan includes probably the biggest count so far of blue duck. One hundred volunteers will trek over 46 central North Island streams and rivers for 70 days this summer to get an accurate picture of just how many birds remain.

The other part of the strategy is an experiment, comparing blue duck numbers and breeding success in areas targeted for predator control with areas where there is none.

Blue duck have also suffered from the loss of vast tracts of their natural habitat by deforestation and agriculture, the taking of water for hydro-electric power and even, says one study, from competition for food by trout.

Coming on top of the natural disasters they have always faced, such as floods washing away nests, blue ducks are staring down the barrel of extinction. One of the biggest arguments surrounding this bird is the effect of hydro-electricity generation.

Like many of New Zealand's birds, the whio lifestyle puts it in direct conflict with human activities and the manipulation of river flows for power has dried up big areas of habitat.

To get resource consents for its Tongariro power scheme, Genesis' contribution to the plan is $1.5 million.

After more than 15 years of wrangling, conservationists also extracted concessions from the power companies - and the money from Genesis for the new protection plan - on the amount of water taken from these rivers, with the upper Whanganui getting increased water flow feeding into areas that have been dry for three decades.

Smith gets up for work around 4.30am, sometimes pulling on a wetsuit damp from the day before. He tramps and wades or uses black tyre tubes to explore these rivers and counts himself incredibly lucky.

"I sometimes wonder what all those other poor people are doing while I'm out here." 

Nick-named "Bubs" as a baby, the name has stuck. The 40-year-old learned his love of the outdoors from an uncle who took him on trips into the Kaimanawa Ranges. He is Ngati Hikairo-ki-tongariro, a hapu of Taupo-based Tuwharetoa, and says he grabbed the opportunity to work for DoC.

For five years he taught conservation skills to wayward youth, trying to instil in them a love of the outdoors as his uncle did for him, taking them skiing, fishing and horse-riding. Seventy per cent of those he taught are still employed, he says.

The whio family is puddling about in the shadow of the far bank, the parents keeping a wary eye on us and a vigilant watch over the chicks.

The adults' slate-grey colouring and blueish tinge gives them almost perfect camouflage against the grey rocks and dark riverbank, their distinctive off-white beaks all that gives them away.

"I don't know what it is about them but when you get up close, and they look at you with that yellow eye, they're mystical birds," Smith says.

He delights in telling a story of adults giving their chicks swimming lessons, beginning with the chicks lined up on a rock and the male parent expertly zig-zagging up a rapid to the next rock. The female then nudges the chicks into the water one by one to copy him.

"They are really committed parents. The male will have a go at you if you get too close."

Smith pulls a red plastic whistle from a pocket to encourage the male bird to make that characteristic call but the bird is having none of it.

Six offspring is the best any pair has managed on this 7km stretch of river, where Smith is monitoring nine pairs and five individuals.

These chicks are about 5 weeks old, with gawky, long legs and a mixture of baby fluff and feathers. At a fully fledged 10 weeks, the adults will then behave aggressively towards them to encourage them to leave home. The juveniles will set up territories nearby but finding a mate can take up to two years.

Often called an "indicator" species, blue duck are extremely fussy about where they live. They are found only on rivers with the highest water quality. They are the only ones among the world's 159 waterfowl species to live year-round on turbulent, fast-flowing rivers.

Whether DoC's new plan will help these shy, reclusive river-dwellers might not be known for another decade. But with their Herald photo-call over, the ducks turn instinctively back upriver.

The male bird's sleek head dives under the water and the chicks follow, bobbing like feathered corks. The family seem to know exactly where they're heading, but the long-term future of these birds is much less certain.