EN
Blue Duck Hymenolaimus malacorhynchos



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.
Turbott, E.G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- C2a(i) A2be; C2a(i)

Red List history
Year Category Criteria
2016 Endangered C2a(i)
2013 Endangered C2a(i)
2012 Endangered C2a(i)
2008 Endangered C2a(i)
2006 Endangered
2004 Endangered
2002 Endangered
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Near Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 199,000 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 1200 good estimated 2005
Population trend Decreasing medium estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 2-100 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 7.1 - - -

Population justification: National surveys and censuses estimated the population to number at least 1,200 mature individuals protected, however, the wider population is estimated to be 2,500 individuals in total. It is difficult to obtain an accurate population estimate due to the widespread nature of the rivers and streams they inhabit in remote areas of New Zealand.

Trend justification: Declines in both distribution and abundance with the result that the species is now restricted to fragmented populations (Whitehead et al. 2008). The overall population is thought to be declining, especially on the South Island (Glaser et al. 2010). Positive population responses have been observed where predator control has taken place, including a 2.8-fold population increase in 4 years with 3 fledged young per pair each year and 94% chick survival (Glaser et al. 2010). In contrast, unmanaged sites had a 91% nest failure rate and productivity was 0.64 fledged young per pair per year (Glaser et al. 2010), clearly indicating that the species is declining in areas without management intervention. The most recent Species Recovery Plan (Glaser et al. 2010) considered that 215 pairs occur in locations that have some form of protection.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
New Zealand N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Temperate major resident
Wetlands (inland) Permanent Rivers/Streams/Creeks (includes waterfalls) major resident
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Livestock farming & ranching Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species disturbance
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Minority (<50%) Unknown Unknown
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Minority (<50%) Unknown Unknown
Stresses
Competition
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Reduced reproductive success
Natural system modifications Dams & water management/use Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) No decline Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets Whole Adults and juveniles Wild International Non-trivial Recent

Recommended citation
BirdLife International (2019) Species factsheet: Hymenolaimus malacorhynchos. Downloaded from http://www.birdlife.org on 23/08/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/08/2019.