Survey shows threatened whio population climbing, proof recovery programme working

Tuesday, 17 August 2021

Numbers of whio breeding pairs in protected sites have almost tripled over the past 10 years, a Department of Conservation survey shows.

The number of breeding pairs of New Zealand’s threatened whio (blue duck) has almost tripled over the past 10 years, according to a Department of Conservation survey.

The species is only found in New Zealand’s fast flowing waters and with an estimated nationwide population of less than 3000, whio are rarer than some kiwi.

Andrew Glaser, DOC Whio Recovery Group lead, said there were now 863 breeding pairs living in protected sites across the country – 565 more pairs since 2011.

Andrew Glaser, Department of Conservation Whio Recovery Group lead, says whio represent healthy, clean river systems but are incredibly vulnerable.

The success of DOC’s Whio Forever national recovery programme and its long association with Genesis Energy to secure the whio’s future were marked at a celebration renewing the partnership at the Hillary Outdoors Education Centre on August 13.

* Threatened ducks increase by 151 per cent in eight NZ rivers since 2011

Those working with whio had blue feet, white hands and red noses from working in the cold water, said Tyrone “Bubs” Smith at the partnership renewal event for the Whio Forever national recovery programme.

The company’s commitment had amounted to many millions over the past 10 years, said Nigel Clark, Genesis chief operating officer, and committing several more millions to another five years in financial and personnel assistance would give the programme security.

The goal for the programme was to take whio from “threatened” status to “at-risk” and grow the national whio population from fewer than 3000 to over 5000 birds, he said.

Linking into the celebration online, DOC director general Lou Sanson said the survey results reinforced the decision of DOC and Genesis to renew their Whio Forever partnership.

Most of the funding from Genesis goes directly towards predator control with more than 5000 traps laid over the past decade. This meant almost 1700 kilometres of river was now protected, providing secure sites where whio could thrive, said Glaser.

Thirty-one community groups working on the programme have been bolstered by the addition of another 13 groups since the inception of the partnership in 2011.

Andrew Glaser at the Mangatepopo Stream. The whio were an iconic New Zealand species and an indicator of a healthy river.

You could always tell people working with whio, said Lake Rotoaira Forest Trust representative Tyrone “Bubs” Smith, of the often cold conditions.

“They have blue feet, white hands and red noses.”

But that commitment meant the nearby Mangatepopo Stream now had the second highest density of whio in the country and where it met the Whanganui River had the highest.

Predator control benefited other species too, Smith said.

Predators have the largest impact on whio during nesting time when eggs, young and females were vulnerable, and also when females were in moult and couldn’t fly, said Glaser.

Whio cannot be moved to predator-free islands because of their reliance on fresh fast-flowing rivers with a good supply of plants and underwater insects and as pairs occupy approximately 1km of water, a fair length of river is needed to sustain a large population.

This habitat preference meant they were susceptible to flood events which destroy nests, fragment broods and wash away food sources.

Their fierce territorial nature makes it difficult to put them with other ducks in captivity though Glaser said there were volunteers rearing whio for release.

Following the celebrations a commemorative predator trap was laid to mark the partnership renewal at the centre.