By Sorrel Hoskin

If you've ever been whitewater rafting you'll know what rapids are: churning water cascading past rocks, a powerful force tumbling down the river. This apparently hostile environment is what the blue duck, or whio, calls home. This little duck can handle white water but is in danger of becoming extinct thanks to mankind.

Whitewater enthusiast: one of Taranaki's blue ducks surveys the river. Image: Dean Caskey Department of Conservation. 

Duck facts

The whio's isolation in New Zealand has resulted in it developing some unique features: Unlike other ducks, whio don't quack - the males whistle sounds just like its name 'fee-oh'. A whio has a streamlined head and big flipper-like webbed feet that help them power through water. The ducks have a big fleshy upper 'lip' on their bills that lets them scrape insect larvae off from the underside of rocks without wearing down their beaks. Believe it or not, they are the only birds that can blush. When the whio is excited its beak turns a pretty shade of pink.

Named after its slate-blue colour the blue duck is one of a kind with no close relatives anywhere in the world. It's one of only four ducks who spend all their lives living on the water. The whio can swim easily in fast moving currents, diving among the rocks as it searches for insect larvae clinging to the boulders under the waterline.

It likes rivers which are clear and fast flowing with plenty of boulders, topped off with a mix of white water and calm pools. But the whios habitat is fast disappearing in New Zealand. Rivers have been dammed to generate electricity and forests have been cleared to make way for farmland. Predators like stoats and rats take eggs and attack adult birds. Goats and possums strip plants from riverbanks. Only 2,500 ducks remain in the wild - making the whio an endangered species.

"We have to make a serious effort to protect the blue duck because we can't move them offshore like other bird species," says Department of Conservation (DoC) biodiversity ranger Dean Caskey. "The islands don't have suitable habitat for ducks - they need the fast flowing water."

Bringing back the duck

So what does Taranaki have to do with all this?  Blue ducks were once common in the region's fast flowing streams. But today there are only occasional sightings of the ducks in the backblocks of East Taranaki. Egmont National Park's fast flowing streams were once home to the little duck but the last official sighting of a whio in the park was back in 1948. In 1987, 1989 and 1991 attempts were made to establish a sustainable population by introducing wild ducks back to the park.

A family of blue duck in Egmont National Park. Image: Dean Caskey, Department of Conservation.

Those initial attempts to release birds in the park weren't very successful. The wild ducks didn't want to stick around and two flew away - these two were discovered up to 130km away back in their old homes. Others were thought to have been killed by stoats. Dean says introducing the birds back to the park has been a matter of trial and error. "We've found out that wild adults move away from the area they're relocated to, wild juniors are very mobile, and birds bred in captivity seem to stay closer to the area we want them."

In 2000, 11 captive bred ducks were introduced to the rushing waters of the national park, and while many of them stuck around, it was soon evident that some of the birds didn't have all the skills needed to survive in the wild. Back then some of the ducks were raised in small cages, with very little room to fly, and a small pond to practice swimming in. "When they were released they had no real idea of how to swim in the rapids and feed," says Dean. "We had ducks that were scared of the sound of the water." The captive breeding team hunted around the country and found the best cage they could. Peacock Springs in Christchurch had just what they needed, a cage big enough for the ducks to fly around in, with a flowing stream where they could practice swimming and learn the life skills needed to survive in the wild. When introduced to the rushing waters of Egmont National Park these newly trained ducks coped better - but were still under threat from predators.

A good news story

Back in 2003 the Central North Island Blue Duck Trust received $530,000 from Genesis Energy, one of the largest single payments in conservation history. This allowed DOC and other agencies to apply for sponsorship to the trust for blue duck projects in the central North Island.

DoC Kaupapa Atawhai manager Charles Mareikura (left) Sandy Parata of Ngati Ruanui and DoC Biodiversity Ranger Dean Caskey release captive bred juveniles into Egmont National Park. Image: Jim Clarkson, Department of Conservation.

Since the programme began in 1999, 82 whio have been released into Egmont National Park from the captive breeding programme. Juvenile ducks have also been introduced from the Whakapapa and Manganui a te au Rivers in the Central North Island. Predator trapping work, covering 6,000 hectares of the park, began in late 2003 and has resulted in a steady increase in the survival rate of the ducks.

But a duck can't be stopped from flying out of the predator controlled area. Those that wander out, or are washed downstream by floods, are vulnerable. Whio have been hit by cars, shot by hunters and killed by stoats.

Keeping track

It's Dean's job to keep an eye on the ducks. He does regular surveys, both from the ground and the air, to check on numbers and whether they've strayed from the protected area.

The ducks are fitted with little radio transmitters so DoC staff can track them and round them up if they have strayed. The best time for spotting ducks is early morning or at dusk when the whio come out to swim and forage on the river. During the middle of the day they sun themselves on rocks or roost hidden in rock caverns and log jams.

All this work has been worth it. In 2005 five pairs of whio attempted nesting. One of these pairs hatched at least two ducklings, and at least one of these made it to fledgling age. It was the first time in more than 50 years that whio ducklings had been seen on the mountain, and the first time transferred birds had bred in Egmont National Park. Dean and other DoC staff were jubilant. "It makes it all worth while. We know we're doing something right."

A good start: a blue duck family rest on river boulders in Egmont National Park. Image: Dean Caskey, Department of Conservation.

The plan is to eventually have a self sustaining population of whio in the park.
Lessons learnt from this programme will be applied to restoring populations around the country with the ultimate aim of removing the whio from the endangered species list.