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Whio adaptations

The whio/blue duck has many adaptations to help it survive in its challenging fast-flowing river habitat. Even newly hatched whio ducklings can negotiate white water and dive for food. Adaptations are grouped into those that are structural, behavioural and physiological.

Looking up at a whio's (duck) lips.

Whio lips

The whio has rubbery soft flaps on the end of its bill to help scrape its food off the surfaces of rocks. Look closely, and you’ll also see the sieve-like structures inside the bill. It uses these to sieve larvae and insects.

Rights: Rob Suisted, Nature’s Pic Images

Structural adaptations of the whio

  • Special soft rubbery ‘lips’ on the end of its bill allow the whio to scrape insect larvae off rocks. These also protect its bill from damage. It is the only duck to have this adaptation.

  • Strong legs for swimming and jumping, with large claws to negotiate difficult terrain.

  • Large webbed feet that collapse like a folded umbrella to create less drag when its feet are moved forwards and open when they are moved back, allowing the whio to pull itself forward through fast water and help it navigate the white water.

  • Streamlined body to help water flow over it so it can effectively swim and dive.

  • Camouflage – the whio is perfectly camouflaged for life in fast-flowing water. The blue/grey colour gives it the name blue duck, and it is very difficult to see in the white water. Its chestnut chest provides camouflage in the riparian zone.

  • Feathers that provide insulation and waterproofing in the cold water.

Unique whio adaptations

This video shows Andrew Glaser, a ranger with the Department of Conservation, explaining how some of the unique adaptations of whio help them survive in their environment. This video is a snippet from a video created as part of the Whio Forever resources. These were developed by DOC in partnership with Genesis Energy.

Rights: Whio Forever

Behavioural adaptations of the whio

  • Roosting and nesting out of sight in overhanging vegetation, protecting it from danger and allowing quick access to the water if in danger and for feeding.

  • Calling to provide warning to other birds regarding danger and also to communicate with its chicks and partner. Listen to the whio here.

  • Evading threats – it can go with the water flow, submerse itself or retreat into roosts.

  • Preening to distribute waterproofing oils along its feathers.

  • Staying under cover in daylight and feeding most often at dawn and dusk.

  • Whio are reluctant flyers but defend their territories by flying low along the river’s edge

  • Defending its territory – it will fight with rival birds.

Physiological adaptations of the whio

  • Production of a natural waterproofing oil to coat its feathers.

  • An excretory process that produces low-toxicity uric acid that is excreted alongside faeces through a cloacal opening.

Related content

Examples of related articles on the Science Learning Hub include Whio – threats and conservation, Whio adaptations and Fantastic whio feathers. There are also several teacher PLD sessions related to whio: Diving into inquiry with whio, Why learn about whio?, Inquiry outside the classroom and Taking action for conservation.

Activity ideas

Activities on the Science Learning Hub related to whio that you may wish to explore include Eliciting prior knowledge, Whio feathers – what are they for? and Whio habitats and conservation.

Useful links

For more detailed information about the whio/blue duck and New Zealand birds in general, you may want to visit Whio forever, New Zealand Birds Online, New Zealand Birds, Department of Conservation, Wetland birds or 10,000 Birds.

Posters are a great way of accessing small chunks of information in a very visual way. These Facts about the whio posters produced by DOC are in both English and Te reo Māori and provide a great starting point for finding out more about one of our most unique endemic birds.

Published:06 August 2017