Over the years, this curious creature has been variously known as the Blue Duck, Mountain Duck, Whistling Duck and Torrent Duck.  But Whio is the Māori name of this bird considered such a taonga (treasure) of Aotearoa that it adorns our $10 banknote.

Whio (or Ko Whio Whio in the South Island) is named for its whistling call, which you can hear in this recording provided by the Department of Conservation.  At about 50 seconds into the recording it really does sound as though the bird is calling its own name.

Whio are endemic to New Zealand and found nowhere else.  There are thought to be less than 3000 of these beautiful waterfowl still in existence, making extinction a disturbingly real possibility.  They rely on fast flowing, bush-lined rivers to provide their insect diet of invertebrates like caddis, mayfly and stonefly larvae. 

They have seen these waterways disappear over the decades and centuries, and have retreated to the wilder parts of rivers that provide protection, and the clean, fast-flowing water they desire and require.

Whio have several unique features that indicate they have been resident in New Zealand since ancient times.  Like many other birds in New Zealand, blue ducks are not great flyers, making them susceptible to attack by mammalian pests, with stoats being the main enemy, particularly for females on the nest. 

While their flying skills need some work, they are world-champion swimmers.  It is a treat to see them stay in total control in swift and turbulent water – occasionally ‘ducking’ to sip a larvae lunch. 

Because they share habitat and food source with fly fishers in particular, it is likely that keen Riversmiths will encounter the Whio, particularly on central north island and east coast rivers.  It is important to give them space, as the pair (usually) you come across will be the only breeding pair for a kilometre or more of their stretch of the river.

This territory of theirs is likely to be close to where they were fledged, and they will probably stay there for life.  They are also thought to mate for life, and both adults care for the chicks hidden in bracken, bush and logs on the riverbank – working hard to survive floods and pest attacks.  With their home base so important, and chick survival rates so low, every pair is critical.  These factors make it impossible to translocate as has been so successful for other birds, so habitat preservation and predator control are vital.

You can help, and learn more by:

• Getting involved in local riparian planting days.
• Join the WhioForever Facebook page
• Get involved in your local predator-control group
• Keep the rivers clean. Don’t just take out what you took in – remove some extra rubbish too
• If you do see Whio – enjoy the moment, but from a distance
• Vote for the Whio in Bird of the Year!

References

Department of Conservation https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/blue-duck-whio/

NZ Birds Online https://nzbirdsonline.org.nz/species/blue-duck

NZBirds.com https://www.nzbirds.com/birds/whio.html

WhioForever Facebook Page https://www.facebook.com/WhioForever