LC
Brown Skua Catharacta antarctica



Taxonomy

Taxonomic note
Catharacta antarctica (del Hoyo and Collar 2014) was previously placed in the genus Stercorarius, following Chu et al. (2009), and split as S. antarcticus and S. lonnbergi, following Sibley and Monroe (1990, 1993).

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
- - -

Red List history
Year Category Criteria
2018 Least Concern
2016 Least Concern
2014 Least Concern
2012 Not Recognised
2008 Not Recognised
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 135,000,000 km2
Extent of Occurrence (non-breeding) 86,100,000 km2
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 26000-28000 mature individuals poor estimated 1996
Population trend decreasing - suspected -
Generation length 17.1 years - - -

Population justification: The total population has been estimated to number c.13,000-14,000 pairs (del Hoyo et al. 1996), assumed to equate to 26,000-28,000 mature individuals, or 39,000-42,000 individuals in total.

Trend justification: The largest known colony of the nominate race, C. antarctica antarctica, has undergone a 47% decline in the last 5 years, as such the species is suspected to be in decline, but the overall magnitude of decline is uncertain.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Angola extant uncertain
Antarctica extant native yes yes
Argentina extant native
Australia extant native yes yes
Bouvet Island (to Norway) extant native yes
Brazil extant uncertain
Chile extant uncertain
Falkland Islands (Malvinas) extant native
French Southern Territories extant native yes
Heard Island and McDonald Islands (to Australia) extant native yes
India extant vagrant
Iran, Islamic Republic of extant vagrant
Maldives extant native
New Zealand extant native yes yes
Norfolk Island (to Australia) extant native
Oman extant vagrant yes
Seychelles extant native
South Africa extant native yes
South Georgia & the South Sandwich Islands extant native yes yes
Sri Lanka extant native
St Helena (to UK) extant uncertain yes
Uruguay extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Antarctica Signy Island
Australia Macquarie Island
French Southern Territories Île aux Cochons
French Southern Territories Île de l'Est
Heard Island and McDonald Islands (to Australia) Heard and McDonald Islands
South Africa Prince Edward Islands Special Nature Reserve
South Georgia & the South Sandwich Islands South Georgia - mainland, islands, islets and stacks
South Georgia & the South Sandwich Islands South Sandwich Islands
St Helena (to UK) Gough Island
St Helena (to UK) Nightingale Island group

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Subantarctic major breeding
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Intertidal Rocky Shoreline suitable breeding
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches suitable breeding
Marine Intertidal Tidepools suitable breeding
Marine Neritic Macroalgal/Kelp suitable non-breeding
Marine Neritic Macroalgal/Kelp suitable breeding
Marine Neritic Pelagic major non-breeding
Marine Neritic Pelagic major breeding
Marine Neritic Seagrass (Submerged) suitable non-breeding
Marine Neritic Seagrass (Submerged) suitable 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 non-breeding
Marine Neritic Subtidal Sandy suitable breeding
Marine Neritic Subtidal Sandy-Mud suitable non-breeding
Marine Neritic Subtidal Sandy-Mud suitable breeding
Marine Oceanic Epipelagic (0-200m) suitable non-breeding
Marine Oceanic Mesopelagic (200-1000m) suitable non-breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Phalcoboenus australis Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Competition, Reduced reproductive success

Recommended citation
BirdLife International (2024) Species factsheet: Brown Skua Catharacta antarctica. Downloaded from https://datazone.birdlife.org/species/factsheet/brown-skua-catharacta-antarctica on 22/11/2024.
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 22/11/2024.