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VU
Ascension Frigatebird Fregata aquila

IUCN Red List Criteria

Critically Endangered  
Endangered  
Vulnerable D2 

IUCN Red List history

Year Category
2012 Vulnerable
2010 Vulnerable
2008 Vulnerable
2005 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Critically Endangered
1994 Critically Endangered
1988 Threatened

Species attributes

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

Distribution

  Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1 medium
Extent of Occurrence non-breeding (km2) 2,790,000 medium
Area of Occupancy breeding/resident (km2) 1 medium
Number of locations 1 -
Fragmentation -

Population & trend

  Estimate Data quality Derivation Year of estimate
No. of mature individuals 17000-21000 medium Estimated 2007
Population trend Unknown not applicable -
Number of subpopulations 1 - - -
Largest subpopulation - - -
Generation length (yrs) 15.5 - - -
Population justification: The current population of mature females is estimated at 9,341 (95% CI: 8,587-10,113), based on census data from 2001-2002, suggesting there may be c.18,682 mature individuals, assuming an equal sex ratio. The confidence intervals for the number of mature females are doubled and rounded to provide a range estimate of 17,000-21,000 for the number of mature individuals, roughly equivalent to 25,000-32,000 individuals in total.
Trend justification: It is difficult to determine the current population trend owing to poor baseline information, the difficulties of carrying out census work and the high number of mature non-breeders in the population (Pickup 1998; Ratcliffe 1999).

Country/Territory distribution

Country/Territory Occurrence status Presence Breeding Non-breeding Passage Resident
St Helena (to UK) Native Extant Yes      
United Kingdom Vagrant Extant   Yes    

Important Bird Areas where this species has triggered the IBA criteria

Country/Territory IBA Name IBA link
St Helena (to UK) Ascension Island: mainland and stacks site factsheet
St Helena (to UK) Boatswainbird Island site factsheet

Habitats & altitude

Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Neritic Macroalgal/Kelp major resident
Marine Neritic Pelagic major resident
Marine Neritic Seagrass (Submerged) major resident
Marine Neritic Subtidal Loose Rock/pebble/gravel major resident
Marine Neritic Subtidal Rock and Rocky Reefs major resident
Marine Neritic Subtidal Sandy major resident
Marine Neritic Subtidal Sandy-Mud major resident
Marine Oceanic Epipelagic (0-200m) major resident
Marine Oceanic Mesopelagic (200-1000m) major resident
Altitude 0 - 0 m 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%) Slow, Significant Decline Medium Impact: 6
Stresses
Indirect ecosystem effects, Species mortality
Biological resource use Hunting & trapping terrestrial animals / Intentional use (species is the target) Timing Scope Severity Impact
Past, Unlikely to Return Majority (50-90%) Rapid Declines Past Impact
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases / Black Rat (Rattus rattus) Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Rapid Declines Past Impact
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases / Domestic Cat (Felis catus) Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Rapid Declines Past Impact
Stresses
Reduced reproductive success, Species mortality

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 (2014) Species factsheet: Fregata aquila. Downloaded from http://www.birdlife.org on 28/08/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/08/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Vulnerable
Family Fregatidae (Frigatebirds)
Species name author (Linnaeus, 1758)
Population size 17000-21000 mature individuals
Population trend Unknown
Distribution size (breeding/resident) 1 km2
Country endemic? Yes
Links to further information
- Summary information on this species