• 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., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and 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
-	-	D1+2

Red List history

Year	Category	Criteria
2022	Vulnerable	D1+2
2016	Endangered	D
2013	Endangered	D
2012	Endangered	D
2008	Endangered	D1
2004	Endangered
2000	Endangered
1996	Endangered
1994	Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	24 km2	medium
Area of Occupancy (breeding/resident)	24 km2	good
Number of locations	2	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	290-310 mature individuals	good	observed	2021
Population trend	stable	good	observed	-
Generation length	3.96 years	-	-	-
Number of subpopulations	2	-	-	-
Percentage of mature individuals in largest subpopulation	84-89%	-	-	-

Population justification: Counts are made pre-breeding (October-November) and post-breeding (March-April), with the former referring to mature individuals. Since November 2012, the pre-breeding numbers have not fallen below 250 mature individuals, with most recent counts of 289, 296 and 298 in Octobers 2018, 2019 and 2020 respectively (T. Thurley in litt. 2021). The majority of birds are on the island of Rangatira, where pre-breeding counts of 244, 263 and 264 were made in 2018, 2019 and 2020, while equivalent counts on the island of Mangere were 45 (15.6% of the total), 33 (11.1%) and 34 (11.4%). Post-breeding numbers ranged 342-369 between 2016 and 2021 (T. Thurley in litt. 2021).

Trend justification: Listed as Nationally Critical in New Zealand (Robertson et al. 2017, 2021), following the independent criteria set out in Townsend et al. (2008). Intensive conservation efforts boosted population sizes rapidly between 1980 and 1989 after the population was depleted to just one breeding female (Old Blue). After intervention ceased, population sizes increased naturally though at a slower rate. The population on Rangatira has increased steadily from c.180 mature individuals in October 2010, to c.260 in October 2020; on Mangere however, the population has declined slightly from a high of 51 in October 2013 to 34 in October 2020. Overall, the population is stable (T. Thurley in litt. 2021).

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

Country/Territory	IBA Name
New Zealand	Mangere
New Zealand	Rangatira South East Island

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Temperate	major	resident
Shrubland	Temperate	major	resident
Altitude	0 - 280 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Causing/Could cause fluctuations		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, Likely to Return		Majority (50-90%)		No decline		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Named species	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Named species	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		No decline		Past Impact
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sturnus vulgaris	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Very Rapid Declines		Medium Impact: 7
		Stresses Species disturbance, Competition, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus scrofa	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Petroica macrocephala	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Hybridisation

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Recommended citation
BirdLife International (2024) Species factsheet: Black Robin Petroica traversi. Downloaded from https://datazone.birdlife.org/species/factsheet/black-robin-petroica-traversi on 04/12/2024.
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 04/12/2024.