LC
Black-tailed Gull Larus crassirostris



Taxonomy

Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
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. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2016 Least Concern
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
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass 561 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 4,910,000
Extent of Occurrence non-breeding (km2) 6,360,000
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals poor estimated 2009
Population trend Stable 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 - - -
Largest subpopulations - - -
Generation length (yrs) 11.5 - - -

Population justification: The global population is estimated to number > c.1,100,000 individuals (Wetlands International 2006), while national population estimates include: c.100-100,000 breeding pairs and c.50-10,000 wintering individuals in China; c.50-1,000 wintering individuals, c.1,000-10,000 individuals on migration and < c.100 breeding pairs in Taiwan; c.10,000-100,000 breeding pairs in Korea; c.10,000-100,000 breeding pairs in Japan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Russia (Brazil 2009).

Trend justification: Although Wetlands International consider the current population trend to be unknown, it is suspected to be stable in the absence of evidence for any declines or substantial threats (del Hoyo et al. 1996).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Australia V Extant
Canada V Extant
China (mainland) N Extant Yes
Hong Kong (China) N Extant
Japan N Extant Yes
Mexico V Extant
North Korea N Extant Yes
Philippines U Extant
Russia N Extant Yes
Russia (Asian) N Extant Yes
South Korea N Extant Yes
Taiwan (China) N Extant
Thailand V Extant
USA V Extant
Vietnam N Extant

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
China (mainland) Dongtou Islands
China (mainland) Haimao Dao Island
China (mainland) Jiushan Islands Nature Reserve
China (mainland) Nanji Islands Nature Reserve
China (mainland) She Dao Island
China (mainland) Wuchishan Dao Nature Reserve
China (mainland) Yushan Islands
Japan Aniva bay / Esashi, Menashidomari / Teurito island - Marine
Japan Bentenjima / Matsumaekojima islets - Marine
Japan Bentenjima islet
Japan Esashi, Menashidomari
Japan Fumishima - Marine
Japan Fumishima islet
Japan Futagojima islets
Japan Futagojima islets / Sanganjima islet - Marine
Japan Kabushima islet
Japan Matsumae islets
Japan Rikuzen Enoshima islets
Japan Rishiri island
Japan Sanganjima islet
Japan Teuri island
Japan Tobishima and Oshakujima islands
Japan Tobishima and Osyakujima islands - Marine
Japan Tshubakijima, Aomatsusima islets
Russia (Asian) Islands in Peter the Great bay
Russia (Asian) Lower Tumen river

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Intertidal Rocky Shoreline major breeding
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc suitable non-breeding
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc suitable breeding
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches suitable breeding
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches suitable non-breeding
Marine Intertidal Tidepools major breeding
Marine Neritic Macroalgal/Kelp suitable non-breeding
Marine Neritic Macroalgal/Kelp suitable breeding
Marine Neritic Pelagic suitable non-breeding
Marine Neritic Pelagic suitable breeding
Marine Neritic Seagrass (Submerged) suitable non-breeding
Marine Neritic Seagrass (Submerged) suitable breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs suitable breeding
Marine Neritic Subtidal Rock and Rocky Reefs suitable non-breeding
Marine Neritic Subtidal Sandy suitable non-breeding
Marine Neritic Subtidal Sandy suitable breeding
Marine Neritic Subtidal Sandy-Mud suitable breeding
Marine Neritic Subtidal Sandy-Mud suitable non-breeding
Altitude   Occasional altitudinal limits  

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food (human) Whole Adults and juveniles Wild Non-trivial Recent
Food - human - - - Non-trivial Recent
Pets Whole Adults and juveniles Wild International Non-trivial Recent
Pets/display animals, horticulture - - - International Non-trivial Recent

Recommended citation
BirdLife International (2017) Species factsheet: Larus crassirostris. Downloaded from http://www.birdlife.org on 18/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/12/2017.