• 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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	D1

Red List history

Year	Category	Criteria
2021	Near Threatened	B1a+2a; D1
2016	Vulnerable	D1
2013	Vulnerable	D1
2012	Vulnerable	D1
2008	Vulnerable	D1
2006	Vulnerable
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,000 km2	medium
Area of Occupancy (breeding/resident)	356 km2	good
Number of locations	7	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	330-1700, 1000-1700 mature individuals	medium	estimated	2017
Population trend	stable	medium	estimated	-
Generation length	3.4 years	-	-	-
Number of subpopulations	3-7	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: It is frequently seen in small numbers (Williams 2013). Surveys on Rose, Ocean, Ewing and Enderby Islands in 1982-1983 produced a population estimate of 215-330 individuals over the four islands, and concluded that the total population was likely to be at least 500, but much less than 1,200 individuals (Williams 1986). Repeat surveys in 1989 on Ewing and Adams Islands estimated a population of 260-389 individuals on the two islands and concluded that the total population was likely to be less than 600 individuals (Moore and Walker 1991).

However, it is thought that the population size has previously been underestimated due to the difficult of detection in grassland habitat (Williams 2005), and populations on Enderby and Rose Islands have increased following mammal eradications (Williams 2013). More recently, the population size has been stated to be at least 2,000 birds (Heather and Robertson 1997, 2005), probably greater than 1,500 individuals (Williams 2005), and likely to exceed 1,000 individuals (Williams 2013). The 2016 Threat Classification of New Zealand's birds assessed the species as Nationally Vulnerable on the basis of a stable population of 1,000 - 5,000 mature individuals (Robertson et al. 2017).

Based on the above estimates, the population size is here placed in the band 500 - 2,500 individuals, roughly equating to 330 - 1,700 mature individuals. On the basis of the 2016 national classification, the population size is most likely to be greater than 1,000 mature individuals.

There are at least three subpopulations, on the Port Ross Islands (Enderby, Rose, Ocean, Ewing, Dundas), Disappointment, and Adams. The Port Ross Islands were estimated to collectively hold approximately 70% of the total population in c.1991 (McClelland 1993). Depending on whether the Port Ross Islands hold separate subpopulations, the largest subpopulation may be that of Adams, or it may be that of the Port Ross Islands. The size of the largest subpopulation is therefore estimated to be 78-1,750 individuals, roughly equating to 52-1,200 mature individuals.

Trend justification: The population appears to be stable and at carrying capacity of the current range islands (Moore and Walker 1991, Williams 2005, Robertson et al. 2017). Population surveys show no evidence of on-going declines, with all islands that currently support populations now free from introduced mammals. The eradication of rabbits from Enderby and Rose Islands in 1993 led to increases in teal populations (Williams 2013). However, the population is unlikely to expand further while cats and pigs remain on the main Auckland Island.

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

Country/Territory	IBA Name
New Zealand	Adams Island
New Zealand	Disappointment Island
New Zealand	Enderby Group

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Subantarctic	major	resident
Marine Intertidal	Rocky Shoreline	major	resident
Marine Intertidal	Tidepools	major	resident
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	resident
Altitude	0 - 200 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Mus musculus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Whole (>90%)		Rapid Declines		Past Impact
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Oryctolagus cuniculus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus domesticus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Unknown		Unknown
		Stresses Species mortality

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Auckland Teal Anas aucklandica. Downloaded from https://datazone.birdlife.org/species/factsheet/auckland-teal-anas-aucklandica on 23/11/2024.
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 23/11/2024.