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

Taxonomic note
Monotypic.

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Extinct
2016	Extinct
2012	Extinct
2008	Extinct
2004	Extinct
2000	Extinct
1994	Extinct
1988	Extinct

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend		-	-	-
Generation length	4.94 years	-	-	-

Population justification: No extant population remains.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
New Zealand	extinct	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Neritic	Estuaries	major	resident
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Canis familiaris	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus norvegicus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus domesticus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Species mortality

Purpose	Scale
Food - human	subsistence, national
Sport hunting/specimen collecting	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: New Zealand Merganser Mergus australis. Downloaded from https://datazone.birdlife.org/species/factsheet/new-zealand-merganser-mergus-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.