• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Difference between revisions of "Blue Duck" - BirdForum Opus

Page Discussion
View source History
(→‎External Links: Multiple GSearches combined)
 
(12 intermediate revisions by 7 users not shown)
Line 1: Line 1:
−
;Hymenolaimus malacorhynchos
+
'''Alternative name: (Maori) Whio'''
−
[[Image:Blue_Duck.jpg|thumb|550px|right|Photo by Moa<br/>Location: Cedar Flats Track, Hokitika, West Coast of South Island, New Zealand]]
+
[[Image:IMG 7991 blue duck 1 cr sm.jpg|thumb|550px|right|Photo &copy; by {{user|martinuk|martinuk}}<br/>Manganui o te Ao River, Manawatu-Wanaganui Region, North Island, [[New Zealand]], January 2010]]
 +
;[[:Category:Hymenolaimus|Hymenolaimus]] malacorhynchos
  
 
==Identification==
 
==Identification==
−
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.
+
Size: 53cm (21in); weight: male 1,000g, female 750g.<br/>
−
 
+
*Bluish-grey overall plumage
 +
*Reddish-chestnut spots on the breast
 +
*Yellow eyes
 +
*Pale pink bill, with the upper [[Dictionary_M-O#M|mandible]] having a thick semi-circular, fleshy 'lip' that overlaps the lower mandible, allowing it to scrape insect larvae off underwater rocks, without causing wear on the bill<br />
 +
Sexes are similar, female is smaller.<br />
 +
Juvenile has less speckling on breast, and has a grey bill and eye.
 +
[[Image:IMG 1465a.JPG|thumb|350px|right|Showing the fleshy 'lip'<br />Photo &copy; by the late '''[http://www.birdforum.net/gallery/showgallery.php/ppuser/67980/cat/500 Rookery]'''<br />Back country, Hawke's Bay, [[New Zealand]], February 2016]]
 
==Distribution==
 
==Distribution==
−
This 54 cm long 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.
+
[[New Zealand]].
−
 
+
====Status====
 +
It is classified as a "Nationally Endangered" species, with current populations at about 2,500 individuals and declining. Early causes for the decline, were habitat loss, especially forest clearance for agriculture. Unless the causes for the decline can be remedied, the species is on the track for extinction.  
 
==Taxonomy==
 
==Taxonomy==
−
The Blue Duck (Hymenolaimus malacorhynchus) is a member of the duck, goose and swan family Anatidae. It is the only member of the genus Hymenolaimus, placed in the shelduck subfamily Tadorninae[citation needed] after previously being considered part of the paraphyletic "perching duck" assemblage. The Māori name is whio, which is an onomatopoetic rendition of the males' call.
+
====Subspecies====
−
 
+
Two subspecies are recognized<sup>[[#References|[1]]]</sup>.
−
==Voice==
+
*''H. m. hymenolaimus''
−
The male's call is an aspirated whistle, and the female's is a rattling growl.
+
:*central and eastern North Island, New Zealand
 +
*''H. m. malacorhynchos''
 +
:*western South Island, New Zealand
  
 
==Habitat==
 
==Habitat==
−
Nests in hollow logs, small caves and other sheltered spots. It is a rare duck, holding territories on fast flowing mountain rivers.
+
Clean, fast flowing, mountain streams, in well-vegetated areas.
 +
==Behaviour==
 +
A strong swimmer not often seen in flight.
  
−
==Behaviour==
+
They are usually active during the early morning and late evening, when they are seen standing on rocks, or with head and neck underwater while feeding. During the rest of the day they hide in caves, log-jams or suchlike and some populations have become almost nocturnal.
−
It is a powerful swimmer even in white water, but is reluctant to fly. It is difficult to find, but not particularly wary when located
+
====Breeding====
 +
Blue Ducks develop strong pair bonds, and an individual pair will stay on the same stretch of river (approx. 1km long) for many years. They will aggressively defend their territory from other Blue Ducks, [[Paradise Shelduck]]s and even gulls or shags. The larger male can live for about 12 years, but the smaller female is shorter lived.
  
 +
Nesting is between August and October, with incubation of 4-9 eggs being done by the female (35 days), while the male stands guard. The down-lined nest of grass and twigs, is built in a scrape in caves, in log jams or under river-side vegetation and consequently often destroyed by spring floods. Breeding success is therefore very variable from year to year.
 +
====Diet====
 +
The diet includes insect larvae and invertebrates.
 +
====Vocalisation====
 +
The male's call is high-pitched whistle ''whio whio'', and the female's is a rattling growl.
 +
==References==
 +
#{{Ref-Clements6thOct22}}#{{Ref-GillDonskerRasmussen22V12.2}}#For more information, see the NZ Department of Conservation website: [http://www.doc.govt.nz/templates/podcover.aspx?id=33059]
 +
#Handbook of the Birds of the World Alive (retrieved July 2016)
 +
{{ref}}
 
==External Links==
 
==External Links==
−
{{GSearch|Hymenolaimus+malacorhynchos}}
+
{{GSearch|"Hymenolaimus malacorhynchos" {{!}} "Blue Duck" {{!}} "Whio"}}
−
[[Category:Birds]]
+
{{GS-checked}}1
 +
<br />
 +
<br />
 +
 
 +
[[Category:Birds]][[Category:Hymenolaimus]]

Latest revision as of 20:19, 27 November 2023

Alternative name: (Maori) Whio

Photo © by martinuk
Manganui o te Ao River, Manawatu-Wanaganui Region, North Island, New Zealand, January 2010
Hymenolaimus malacorhynchos

Identification

Size: 53cm (21in); weight: male 1,000g, female 750g.

  • Bluish-grey overall plumage
  • Reddish-chestnut spots on the breast
  • Yellow eyes
  • Pale pink bill, with the upper mandible having a thick semi-circular, fleshy 'lip' that overlaps the lower mandible, allowing it to scrape insect larvae off underwater rocks, without causing wear on the bill

Sexes are similar, female is smaller.
Juvenile has less speckling on breast, and has a grey bill and eye.

Showing the fleshy 'lip'
Photo © by the late Rookery
Back country, Hawke's Bay, New Zealand, February 2016

Distribution

New Zealand.

Status

It is classified as a "Nationally Endangered" species, with current populations at about 2,500 individuals and declining. Early causes for the decline, were habitat loss, especially forest clearance for agriculture. Unless the causes for the decline can be remedied, the species is on the track for extinction.

Taxonomy

Subspecies

Two subspecies are recognized[1].

  • H. m. hymenolaimus
  • central and eastern North Island, New Zealand
  • H. m. malacorhynchos
  • western South Island, New Zealand

Habitat

Clean, fast flowing, mountain streams, in well-vegetated areas.

Behaviour

A strong swimmer not often seen in flight.

They are usually active during the early morning and late evening, when they are seen standing on rocks, or with head and neck underwater while feeding. During the rest of the day they hide in caves, log-jams or suchlike and some populations have become almost nocturnal.

Breeding

Blue Ducks develop strong pair bonds, and an individual pair will stay on the same stretch of river (approx. 1km long) for many years. They will aggressively defend their territory from other Blue Ducks, Paradise Shelducks and even gulls or shags. The larger male can live for about 12 years, but the smaller female is shorter lived.

Nesting is between August and October, with incubation of 4-9 eggs being done by the female (35 days), while the male stands guard. The down-lined nest of grass and twigs, is built in a scrape in caves, in log jams or under river-side vegetation and consequently often destroyed by spring floods. Breeding success is therefore very variable from year to year.

Diet

The diet includes insect larvae and invertebrates.

Vocalisation

The male's call is high-pitched whistle whio whio, and the female's is a rattling growl.

References

  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of Birds of the World: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/
  2. Gill, F, D Donsker, and P Rasmussen (Eds). 2022. IOC World Bird List (v 12.2) DRAFT. Doi 10.14344/IOC.ML.12.2. http://www.worldbirdnames.org/
  3. For more information, see the NZ Department of Conservation website: [1]
  4. Handbook of the Birds of the World Alive (retrieved July 2016)

Recommended Citation

External Links

GSearch checked for 2020 platform.1

Retrieved from ‘https://www.birdforum.net/wiki/index.php?title=Blue_Duck&oldid=271022’
Back
Top