The captive-reared birds are taking the next steps on their journey to release, where they will bolster the wild population of this highly threatened duck.
Biodiversity Ranger Karen (Ardy) Ardin says it's like highschool for ducks, making sure they have the skills they need for the real world.
"They have three to five weeks with us, learning to swim and feed in fast flowing water, giving them the best chance of survival when they are released."
With fewer than 3,000 whio in the world, these four will be an important addition to the wild population.
Ardy says ensuring a healthy release is a full-time job.
"We're lucky to have dedicated volunteers from our community partners Project Tongariro – we couldn't do it without them."
Visitors are encouraged to take the chance to see these special birds close-up over the next few weeks.
Background information
About whio/blue duck
The whio is a threatened species of native duck that is only found in New Zealand's fast flowing waters. Featured on New Zealand's $10 note and with an estimated nationwide population of less than 3,000 birds, whio are rarer than kiwi.
Whio are adapted to live on fast-flowing rivers, so finding whio means you will also find clean, fast-flowing water with a good supply of underwater insects.
This makes whio important indicators of ecosystem health – they only exist where there is high quality clean and healthy waterways.
Conservation issues
Whio are predated by stoats, ferrets and cats with the largest impact during nesting time when eggs, young and females are vulnerable, and also when females are in moult and can't fly.
Extensive trapping can manage these predators. Work in key whio habitats by DOC and Genesis on the Whio Forever Project has already seen an increase in whio numbers.
Whio cannot be moved to predator-free islands like other species because of their reliance on fast-flowing rivers.
Pairs occupy approximately 1 km of water – so they need a lot of river to sustain a large population. They fiercely defend their territories, which makes it difficult to put them with other ducks in captivity.
Whio are susceptible to flood events, which destroy nests, fragment broods and wash away their valued food source.
