Red-legged Kittiwake Rissa brevirostris


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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A4ac

Red List history
Year Category Criteria
2018 Vulnerable A4ac
2017 Vulnerable A4ac
2016 Vulnerable A2ac+3c+4ac
2013 Vulnerable A2ac+3c+4ac
2012 Vulnerable A2ac+3c+4ac
2010 Vulnerable A2a,c; A3c; A4a,c
2008 Vulnerable A2a,c; A3c; A4a,c
2006 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Land-mass type - shelf island
Average mass 377 g

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,320,000 medium
Extent of Occurrence non-breeding (km2) 13,400,000 medium
Extent of Occurrence breeding/resident (km2) 1,740 medium
Number of locations 13 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 100000-499999 medium estimated 2017
Population trend Decreasing good 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) 30-49 - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 12.9 - - -

Population justification:

The Pribilof Islands account for >82% of the breeding population, with an estimated 235,624 breeding birds at St. George Island (per Goyert et al. 2017), 1,400 birds at St. Paul Island, and 172 at Otter Island (Thomson et al. 2014). The estimate for St. George is derived from a nest census conducted in 1995, while the estimates for St. Paul and Otter islands were taken from the most recent (2014) direct count of all attending birds conducted by the Alaska Maritime National Wildlife Refuge. The Commander Islands contain the only known Red-leggged Kittiwake colonies outside of the United States. These islands contain approximately 32,300 breeding birds (Vyatkin and Artyukhin 1994, del Hoyo et al. 1996, Artukhin 1999), which is approximately 14% of the breeding population. The colonies on Bering Island support by far the largest portion of the breeding birds of the Commander Islands, with an estimated 30,600 breeding birds in 1993 (Vyatkin and Artyukhin 1994). Recent counts for Bering Island and the other colonies in the Commander Islands group are not available. In the Aleutian Islands, Buldir Island (and its associated offshore rocks [Outer and Middle rocks]) is the largest colony with an estimated 8,605 breeding birds (per Goyert et al. 2017). Bogoslof Island and nearby Fire Island have a combined total of approximately 900 birds (Byrd et al. 2001). The remaining small colonies in the Aleutian Islands at Amak, Unalga, Koniuji and Chagulak islands contain fewer than 20 birds each (Byrd et al. 1997, 2004) and combined with Bogoslof Island account for <1% of the population. Overall, the population size in Alaska has been estimated at 247,300 breeding adults (Goyert et al. 2017), along with the population size of 32,300 in the Commander Islands, Russia. This gives a global population size estimate of 279,600 mature individuals, placed here in the range 100,000-499,999 mature individuals.

Trend justification: From the mid-1970s to mid-1990s, the known population declined by >40%. Most of this decline was on the Pribilof Island of St. George, where a precipitous (>50%) decline in breeding numbers occurred (Byrd and Williams 1993). The decline on St. George continued through the early 1990s, but subsequently has shown recovery (Byrd et al. 2008, Jason and Romano 2017). The small population on St. Paul Island declined by >80% from the mid-1970s through 2008 (Thomson et al. 2014), though since 2008, the population appears to have stabilised (M. Romano in litt. 2016). There is some evidence of a slight decline on the Commander Islands, but no counts are available prior to the late 1980s and it is unclear whether this was a trend or just interannual fluctuations (Byrd et al. 1997). No recent trend information is available for any of the Commander Islands. Of the remaining small colonies (all <5% of the population) the number of breeding birds at Buldir Island may have increased by as much as 55% between 1992 and 2014, and the number of breeding birds may have increased at Bogoslof Island in the mid-1990s (Byrd et al. 1997). Therefore, based on this evidence the decline over the past 3 generations (c.39 years) likely no longer meets the threshold for Vulnerable. Goyert et al. (2017), however, state that there have been recent declines in the species. With this uncertainty, the past and ongoing population reduction is very tentatively retained in the range 30-49% over 3 generations, though with further evidence of population trends, this precautionary assessment will require revision.

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Canada N Extant Yes
Japan V Extant
Russia N Extant Yes
Russia (Asian) N Extant Yes
USA N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Russia (Asian) Stolbovoy island
Russia (Asian) Commander Islands
USA Buldir Island
USA Bering Sea Shelf Edge, marine
USA Bogoslof Island and Fire Island
Russia (Asian) Commander islands - Marine
USA St George Island
USA St Paul Island
USA Bering Sea Shelf Edge 168W56N
USA St George Island Marine
USA Buldir Island Colony
USA St George Island Colony

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Neritic Pelagic major breeding
Marine Neritic Pelagic major non-breeding
Marine Oceanic Epipelagic (0-200m) suitable non-breeding
Marine Oceanic Epipelagic (0-200m) suitable breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Fishing & harvesting aquatic resources - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Indirect ecosystem effects, Competition, Reduced reproductive success
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Species mortality
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Ongoing Whole (>90%) Slow, Significant Declines Medium Impact: 7
Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Future Minority (<50%) Rapid Declines Low Impact: 4
Reduced reproductive success, Species mortality

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

Recommended citation
BirdLife International (2022) Species factsheet: Rissa brevirostris. Downloaded from on 03/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 03/12/2022.