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

Taxonomic note
Haematopus ostralegus and H. finschi were previously lumped as H. ostralegus (del Hoyo and Collar 2014), but have once more been recognised as species following a review of additional material allowing the scoring of the taxa against each other and H. longirostris, H. chathamensis, and H. unicolor (G. Ehmke in litt. 2015, Hayman et al. 1986, Marchant and Higgins 1993). This restores the taxonomic position of the two species prior to del Hoyo and Collar (2014).

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2019. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 4. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v4_Dec19.zip.
Marchant, S.; Higgins, P. J. 1993. Handbook of Australian, New Zealand and Antarctic birds, 2: raptors to lapwings. Oxford University Press, Melbourne.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Least Concern
2016	Not Recognised
2014	Not Recognised
2012	Least Concern
2009	Least Concern
2008	Least Concern
2004	Least Concern
2000	Lower Risk/Least Concern
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	55,700 km2
Extent of Occurrence (non-breeding)	556,000 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	50000-99999 mature individuals	poor	suspected	2014
Population trend	decreasing	-	inferred	-
Generation length	13.7 years	-	-	-

Population justification: The population size was estimated to be 112,675 individuals in 1983-94 (Sagar et al. 1999). Numbers are thought to have increased for a few years after this, after which they declined, possibly back to the 1988 level (Sagar & Veitch 2014). The population is therefore suspected to be c.113,000, roughly equivalent to 75,333 mature individuals, here placed in the band 50,000-99,999 mature individuals.

Trend justification: South Island Oystercatcher numbers declined to <10,000 prior to 1940 as a result of hunting following the arrival of European migrants (Sagar & Veitch 2014). The species was subsequently protected from hunting in 1940, after which numbers increased to an estimated 49,000 in 1970-71 (Baker 1973) and then c.113,000 in 1983-94 (Sagar et al. 1999). Numbers are thought to have increased for a further few years, after which they began to decline once again, possibly back to the 1988 level (Sagar & Veitch 2014).  This decline is thought to currently still be occurring (Sagar & Veitch 2014), but the rate of decline is unknown and the species has not undergone an overall reduction over the past three generations.

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

Country/Territory	IBA Name
New Zealand	Firth of Thames
New Zealand	Manukau Harbour
New Zealand	Pegasus Bay Coast

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Arable Land	suitable	breeding
Artificial/Terrestrial	Pastureland	suitable	non-breeding
Grassland	Tundra	suitable	breeding
Marine Intertidal	Mud Flats and Salt Flats	major	non-breeding
Marine Intertidal	Rocky Shoreline	major	non-breeding
Marine Intertidal	Salt Marshes (Emergent Grasses)	major	non-breeding
Marine Intertidal	Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc	major	non-breeding
Marine Intertidal	Shingle and/or Pebble Shoreline and/or Beaches	major	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	major	breeding
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	major	breeding
Altitude	0 - 1800 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Marine & freshwater aquaculture - Industrial aquaculture	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Species disturbance, Species mortality
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation, Reduced reproductive success
Energy production & mining	Renewable energy	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Competition, Reduced reproductive success, Species mortality
Pollution	Domestic & urban waste water - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: South Island Oystercatcher Haematopus finschi. Downloaded from https://datazone.birdlife.org/species/factsheet/south-island-oystercatcher-haematopus-finschi on 18/12/2024.
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 18/12/2024.