Learn about Whio

Native Birds
Written By Rachel Thompson

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What are Whio?

Whio - sometimes called ‘blue ducks’ - are very special birds found only in Aotearoa. One of the few duck species in the world that live in fast flowing rivers, whio have some very cool adaptations to help them survive, like big webbed feet that fold like umbrellas and a rubber bumper on their bill! Whio eat freshwater macroinvertebrates from clean, clear, rocky streams. Their bills have this rubbery ‘bumper’ so that they can dig around under rocks and get bugs that live in the water such as mayfly and stonefly nymphs.

Learn more about freshwater macroinvertebrates in our resource here.

Whio need to be protected!

Whio are very endangered, with less than 3000 left, making them 20 times rarer than kiwi! It takes a week for a whio to lay a nest of eggs, then it takes 40 days to incubate the eggs. While sitting on nests females are vulnerable to predators.

When the chicks fledge (leave the nest), the adults moult (lose their feathers and grow new ones). This takes 2-3 weeks, and during this time they can’t fly, so again are vulnerable to predators. They are literally ‘sitting ducks’!

Whio evolved with avian (bird) predators that hunted with their eyes, so they use camouflage to hide. And they do have great camouflage in rocky rivers! Unfortunately, this doesn’t work for introduced mammalian predators that use smell to hunt. Their main predators are stoats and ferrets, but dogs and cats can predate whio too. Rats and hedgehogs may eat their chicks and eggs.

  • 40% of females are predated while sitting on nests

  • 90% of whio nests fail without help

    How can you help?

  • You could set a backyard trap, or volunteer to check a local trapline to help protect birds such as whio.

  • If you have a dog - Always keep your dog on a lead if you are in an area with vulnerable native birds. If there are signs saying ‘No Dogs’, do not take your dog into the area. If possible, have your dog avian aversion trained.

  • If you have a cat - Try to keep your cat inside at night. Make sure that your cat is de-sexed and microchipped. Keep it well-fed and get a colourful colour with a bell. You could even make a catio! Learn lots more ideas for cats here.

 

Resources

Fantastic DOC Whio Resources and Activities:

Rachel Thompson
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