• 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
-	-	-

Red List history

Year	Category	Criteria
2020	Near Threatened	C2a(ii)
2016	Vulnerable	C2a(ii)
2012	Vulnerable	C2a(ii)
2008	Vulnerable	C2a(ii)
2006	Vulnerable
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	95,900 km2	medium
Extent of Occurrence (non-breeding)	34,500,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	10000 mature individuals	medium	estimated	2019
Population trend	decreasing	poor	suspected	-
Rate of change over the past 10 years/3 generations (longer of the two periods)	5-10%	-	-	-
Generation length	7.7 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population is estimated to number 10,000 mature individuals (Andres 2012 per Partners in Flight 2019). Despite breeding in two different areas in Alaska, the species does not show spatial segregation in the non-breeding grounds (Sonsthagen et al. 2015) and can therefore be considered one subpopulation.

Trend justification: The population trend is difficult to quantify. On the breeding grounds in the Arctic, trends are inconclusive. There is concern that the species may be undergoing a decline: Wetlands International (2020) list the species as declining between 2002 and 2011. Partners in Flight (2019) and Smith et al. (2020) describe the trend as unknown or possibly declining, while a population survey found no evidence of declines (G. Butcher in litt. 2007). On the non-breeding grounds in Oceania, the species is thought to be stable in French Polynesia (P. Raust in litt. 2020) or even increasing on Oahi (Hawaii) due to recolonisation events (Tibbitts et al. 2020). Overall, there seems to be growing evidence that population declines have stopped or at least slowed down considerably. In the absence of data covering the entire range, it is precautionarily suspected that the species has been undergoing a slow decline over the past three generations (23.1 years), which is unlikely to exceed a rate of 5-10%.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
American Samoa	extant	native			yes
Chile	extant	native			yes
Cook Islands	extant	native			yes
Fiji	extant	native				yes
French Polynesia	extant	native			yes
Guam (to USA)	extant	native			yes
Indonesia	extant	vagrant			yes
Japan	extant	vagrant			yes
Kiribati	extant	native			yes
Marshall Islands	extant	native			yes
Micronesia, Federated States of	extant	native			yes
Nauru	extant	native			yes
New Zealand	extant	native			yes
Niue (to New Zealand)	extant	native			yes
Northern Mariana Islands (to USA)	extant	native			yes
Papua New Guinea	extant	vagrant
Philippines	extant	vagrant			yes
Pitcairn Islands (to UK)	extant	native			yes
Samoa	extant	native			yes
Solomon Islands	extant	native			yes
Tokelau (to New Zealand)	extant	native			yes
Tonga	extant	native			yes
Tuvalu	extant	native			yes
United States Minor Outlying Islands (to USA)	extant	native			yes
USA	extant	native		yes
Wallis and Futuna Islands (to France)	extant	native			yes

Country/Territory	IBA Name
French Polynesia	Apataki, Arutua et Kaukura (Îles Palliser)
French Polynesia	Fangataufa
French Polynesia	Maria
French Polynesia	Motu de l'ouest et du sud de Rangiroa
French Polynesia	Nord-ouest de Nuku Hiva
French Polynesia	Reitoru
French Polynesia	Tahanea
French Polynesia	Tenararo
Kiribati	Millenium (Caroline) Island
Pitcairn Islands (to UK)	Henderson Island
Pitcairn Islands (to UK)	Oeno Island
United States Minor Outlying Islands (to USA)	Howland Island
United States Minor Outlying Islands (to USA)	Jarvis Island
United States Minor Outlying Islands (to USA)	Palmyra Atoll
USA	Andreafsky Wilderness
USA	Central Seward Peninsula
USA	Central Yukon - Kuskokwim
USA	James Campbell National Wildlife Refuge
USA	Northwestern Hawaiian Islands

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Tundra	major	breeding
Marine Coastal/Supratidal	Coastal Brackish/Saline Lagoons/Marine Lakes	major	non-breeding
Marine Intertidal	Mud Flats and Salt Flats	suitable	non-breeding
Marine Intertidal	Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc	suitable	non-breeding
Altitude	0 - 350 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Causing/Could cause fluctuations		Low Impact: 5
		Stresses Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Minority (<50%)		Slow, Significant Declines		Past Impact
		Stresses Species mortality
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Canis familiaris	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Causing/Could cause fluctuations		Medium Impact: 6
		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		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 - Sus domesticus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Causing/Could cause fluctuations		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Corvus corax	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Stercorarius parasiticus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Vulpes vulpes	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Reduced reproductive success
Pollution	Industrial & military effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species mortality

Purpose	Scale
Food - human	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Bristle-thighed Curlew Numenius tahitiensis. Downloaded from https://datazone.birdlife.org/species/factsheet/bristle-thighed-curlew-numenius-tahitiensis 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.