NT
Bristle-thighed Curlew Numenius tahitiensis



Taxonomy

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.

IUCN Red list criteria met and history
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
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 95,900 medium
Extent of Occurrence non-breeding (km2) 34,500,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 10000 medium estimated 2019
Population trend Decreasing poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -
Generation length (yrs) 7.7 - - -

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 distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
American Samoa N Extant Yes
Chile N Extant Yes
Cook Islands N Extant Yes
Fiji N Extant Yes
French Polynesia N Extant Yes
Guam (to USA) N Extant Yes
Indonesia V Extant Yes
Japan V Extant Yes
Kiribati N Extant Yes
Marshall Islands N Extant Yes
Micronesia, Federated States of N Extant Yes
Nauru N Extant Yes
New Zealand N Extant Yes
Niue (to New Zealand) N Extant Yes
Northern Mariana Islands (to USA) N Extant Yes
Papua New Guinea V Extant
Philippines V Extant Yes
Pitcairn Islands (to UK) N Extant Yes
Samoa N Extant Yes
Solomon Islands N Extant Yes
Tokelau (to New Zealand) N Extant Yes
Tonga N Extant Yes
Tuvalu N Extant Yes
United States Minor Outlying Islands (to USA) N Extant Yes
USA N Extant Yes
Wallis and Futuna Islands (to France) N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Pitcairn Islands (to UK) Oeno Island
Pitcairn Islands (to UK) Henderson Island
USA Andreafsky Wilderness
Fiji Rotuma
French Polynesia Bellinghausen
French Polynesia Scilly (Manuae)
French Polynesia Maupihaa (Mopelia)
French Polynesia Morane
French Polynesia Motane (Mohotani)
French Polynesia Nord-ouest de Nuku Hiva
French Polynesia Motu de l'ouest et du sud de Rangiroa
French Polynesia Rapa
French Polynesia Tahuata
French Polynesia Reitoru
French Polynesia Kaukura
French Polynesia Arutua
French Polynesia Apataki
French Polynesia Tikehau
French Polynesia Tahanea
French Polynesia Fatu Huku
French Polynesia Anuanuraro
French Polynesia Maria
French Polynesia Tupai
French Polynesia Tekokota
French Polynesia Maiao
French Polynesia Mehetia
French Polynesia Pentes du mont Hiro de Raivavae
Tonga Maninita, Taula, Lualoli
USA Central Seward Peninsula
USA Andreafsky Wilderness
USA Central Yukon - Kuskokwim
USA James Campbell National Wildlife Refuge
French Polynesia Manuae, Motu One et Maupihaa
French Polynesia Apataki, Arutua et Kaukura (Îles Palliser)
Kiribati Enderbury Island
Kiribati Rawaki (Phoenix Island)
Kiribati Kiritimati (Christmas Island)
Kiribati Millenium (Caroline) Island
French Polynesia Fangataufa
French Polynesia Tenararo
USA Northwestern Hawaiian Islands
Cook Islands Atiu
Cook Islands Takutea Wildlife Sanctuary
Cook Islands Mangaia
Cook Islands Miti'aro Island
Cook Islands Ma'uke Island
Cook Islands Suwarrow Atoll National Park
United States Minor Outlying Islands (to USA) Wake Island
United States Minor Outlying Islands (to USA) Baker Island
United States Minor Outlying Islands (to USA) Howland Island
United States Minor Outlying Islands (to USA) Johnston Atoll
United States Minor Outlying Islands (to USA) Palmyra Atoll
United States Minor Outlying Islands (to USA) Jarvis Island
Pitcairn Islands (to UK) Ducie Island
Pitcairn Islands (to UK) Pitcairn Island
French Polynesia Vahanga
Kiribati Kotabu and Nabini Islet
Tokelau (to New Zealand) Tokelau

Habitats & altitude
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  

Threats & impact
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

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent

Recommended citation
BirdLife International (2022) Species factsheet: Numenius tahitiensis. Downloaded from http://www.birdlife.org on 26/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/06/2022.