• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

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

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	548,000 km2	medium
Number of locations	11-100	-
Severely fragmented?	yes	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	71000-118000 mature individuals	medium	estimated	2012
Population trend	decreasing	good	estimated	2011-2021
Rate of change over the past 10 years/3 generations (longer of the two periods)	20-29%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Generation length	3.4 years	-	-	-
Number of subpopulations	2-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

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	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
New Zealand	extant	native	yes

Country/Territory	IBA Name
New Zealand	Northern Titi Muttonbird Islands

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

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

Purpose	Scale
Food - human	subsistence, national
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Weka Gallirallus australis. Downloaded from https://datazone.birdlife.org/species/factsheet/weka-gallirallus-australis on 26/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 26/12/2024.