Blue Duck

Blue Duck
Blue Duck at Staglands, Akatarawa Valley
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Subfamily: Tadorninae
Genus: Hymenolaimus
G.R. Gray, 1843
Species: H. malacorhynchos
Binomial name
Hymenolaimus malacorhynchos
(Gmelin, 1789)
Subspecies
  • H. m. malacorhynchos
    South Island Blue Duck

  • H. m. hymenolaimus
    North Island Blue Duck

The Blue Duck (Hymenolaimus malacorhynchos) is a member of the duck, goose and swan family Anatidae endemic to New Zealand. It is the only member of the genus Hymenolaimus,[2] placed in the shelduck subfamily Tadorninae after previously being considered part of the paraphyletic "perching duck" assemblage. The Māori name, sometimes used in English, is whio, which is an onomatopoetic rendition of the males' call.

The Blue Duck features on the reverse side of the New Zealand $10 note.

Contents

Description

The Blue Duck is a dark slate-grey with a chestnut-flecked breast and a paler bill and eye. The pinkish-white bill has fleshy flaps of skin hanging from the sides of its tip. The male's call is an aspirated whistle, and the female's is a rattling growl.[2] The Blue Duck is born with a green beak for just 8 hours after birth; where it then develops to its final colour.

Ecology and behaviour

This species is an endemic resident breeder in New Zealand, nesting in hollow logs, small caves and other sheltered spots. It is a rare duck, holding territories on fast flowing mountain rivers. It is a powerful swimmer even in strong currents, but is reluctant to fly. It is difficult to find, but not particularly wary when located.

Status

The Blue Duck is a very localised species now threatened by predation from introduced mammals especially stoats, competition for its invertebrate food with introduced trout, and damming of mountain rivers for hydroelectric schemes. It is listed as Nationally Endangered in the New Zealand Threat Classification System. In 2009 the New Zealand Department of Conservation started a ten-year recovery programme to protect the species at eight sites using predator control and then re-establish populations throughout their entire former range.[3]

References

  1. ^ BirdLife International (2008). "Hymenolaimus malacorhynchos". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Archived from the original on 21 November 2011. http://www.webcitation.org/63N2dFqU7. 
  2. ^ a b Madge, Steve; Burn, Hilary (1987). Wildfowl: an identification guide to the ducks, geese and swans of the world. London: Christopher Helm. ISBN 0-7470-2201-1. 
  3. ^ Glaser, Andrew; Andrew, Paul; Elliott, Graeme; Edge, Kerri-Anne (December 2010). Whio/blue duck (Hymenolaimus malacorhynchos) recovery plan 2009–2019. Threatened Species Recovery Plan 62. Wellington, N.Z.: Department of Conservation. ISBN 978-0-478-14841-1. http://csl.doc.govt.nz/upload/documents/science-and-technical/tsrp62.pdf. 

Further reading

External links