VU
Weka Gallirallus australis



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. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
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
- - A3bce+4bce

Red List history
Year Category Criteria
2018 Vulnerable A3bce+4bce
2016 Vulnerable A3bce+4bce
2012 Vulnerable A3bce+4bce
2008 Vulnerable A3b,c,e
2006 Vulnerable
2005 Vulnerable
2004 Vulnerable
2000 Vulnerable
1994 Lower Risk/Near Threatened
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency Low
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 548,000 medium
Number of locations 11-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 71000-118000 medium estimated 2012
Population trend Decreasing good 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) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation 1-89 - - -
Generation length (yrs) 3.4 - - -

Population justification: The population of subspecies australis is estimated to number 50,000-100,000 individuals, although with large fluctuations; subspecies greyi c.11,000 (A. J. Beauchamp in litt. 2012); subspecies hectori 38,000-58,000 on Chatham and Pitt Islands, and subspecies scotti fewer than 8,000 on the islands surrounding Stewart Island (A. J. Beauchamp in litt. 2012). On the basis of these estimates, the total population is thought to number 107,000-177,000 individuals, probably including 71,000-118,000 mature individuals.

Trend justification: This species's population is suspected to have continued to decrease at some level during this decade, in line with previous background declines; notably, significant declines in G. a. greyi since the early 1980s and dramatic fluctuations in G. a. australis, that have included plummeting numbers in north Westland, with declines of over 90% in c.20 years (S. Bartle in litt. 2000) and declines in Golden Bay (A. J. Beauchamp in litt. 2012). Future population declines are predicted to intensify, as climate change is likely to increase the probability of such events occurring, particularly for small island populations (G. Bramley in litt. 2012).


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
New Zealand Breaksea Sound
New Zealand Chalky Preservation Inlets
New Zealand Dusky Sound Wet Jacket Arm
New Zealand Open Bay Islands
New Zealand Paterson Inlet The Neck
New Zealand Port Adventure
New Zealand Port Pegasus
New Zealand Rangiauria Pitt Island
New Zealand Ruapuke
New Zealand Solander Islands
New Zealand Southern Titi Muttonbird Islands
New Zealand Northern Titi Muttonbird Islands
New Zealand North Coast Rakiura

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Temperate major resident
Grassland Temperate major resident
Marine Coastal/Supratidal Coastal Sand Dunes suitable resident
Marine Intertidal Rocky Shoreline suitable resident
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc suitable resident
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches suitable resident
Shrubland Temperate major resident
Wetlands (inland) Permanent Freshwater Lakes (over 8ha) major resident
Wetlands (inland) Permanent Freshwater Marshes/Pools (under 8ha) major resident
Altitude 0 - 1500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Unintentional effects (species is not the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species mortality
Climate change & severe weather Droughts Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Future Whole (>90%) Rapid Declines Medium Impact: 6
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Erinaceus europaeus 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 - Felis catus Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mustela erminea Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mustela furo Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Oryctolagus cuniculus Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Competition
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Parabuteo unicinctus Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus exulans Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus norvegicus Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2021) Species factsheet: Gallirallus australis. Downloaded from http://www.birdlife.org on 23/04/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/04/2021.