LC
Slaty-backed Gull Larus schistisagus



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. 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 1323 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 5,080,000
Extent of Occurrence non-breeding (km2) 9,050,000
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals poor estimated 2009
Population trend Unknown not applicable -
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.25,000-1,000,000 individuals (Wetlands International 2006), while national population estimates include: c.50-10,000 wintering individuals in China; c.50-10,000 wintering individuals in Korea; c.10,000-100,000 breeding pairs and > c.1,000 wintering individuals in Japan and c.10,000-1 million breeding pairs and > c.1,000 individuals on migration in Russia (Brazil 2009).

Trend justification: The population trend is difficult to determine because of uncertainty over the extent of threats to the species (del Hoyo et al. 1996).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Canada N Extant
China (mainland) N Extant Yes
Guam (to USA) V Extant
Japan N Extant Yes
North Korea N Extant Yes
Russia N Extant Yes
Russia (Asian) N Extant Yes
South Korea N Extant
Taiwan, China N Extant Yes
USA N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Japan Aniva bay / Esashi, Menashidomari / Teurito island - Marine
Japan Daikoku islet
Japan Daikokujima islet / Kunashir island / Shiretoko, Mount Syari-dake - Marine
Japan Shiretoko, Mount Syari-dake
Japan Teuri island
Japan Tomoshiri and Chitomoshiri islets
Japan Yururi and Moyururi islets
Russia (Asian) Avachinskaya Bay and Starichkov Island
Russia (Asian) Bogoslova Island
Russia (Asian) Bol'shaya River Estuary
Russia (Asian) Cape Oria
Russia (Asian) Karaginskiy Island
Russia (Asian) Khalpili Islands and Impoveyem Bay
Russia (Asian) Kuril islands (between Urup and Paramushir)
Russia (Asian) Moroshechnaya River
Russia (Asian) Nerpich'ye Lake and Kamchatka River delta
Russia (Asian) Ola lagoon
Russia (Asian) Signal'nyy Island
Russia (Asian) Tyuleniy Island
Russia (Asian) Utashud Island
Russia (Asian) Utkholok river
Russia (Asian) Verkhoturova Island

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

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets Whole Adults and juveniles Wild International Non-trivial Recent

Recommended citation
BirdLife International (2018) Species factsheet: Larus schistisagus. Downloaded from http://www.birdlife.org on 14/11/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 14/11/2018.