LC
Masked Booby Sula dactylatra



Taxonomy

Taxonomic note
Sula dactylatra (AOU 1998 + updates) and Sula tasmani (Christidis and Boles 1994) have been lumped as S. dactylatra following Christidis and Boles (2008).

Taxonomic source(s)
Christidis, L. and 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. 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
2012 Least Concern
2010 Least Concern
2008 Not Recognised
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 211,000,000 medium
Extent of Occurrence non-breeding (km2) 128,000,000 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 0
Population trend Decreasing inferred -
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) 16.3 - - -

Population justification: The global population size has not been quantified, but this species is described as 'fairly common' (Stotz et al. 1996).

Trend justification: The population is suspected to be in decline owing to predation by invasive species and unsustainable levels of exploitation.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
American Samoa N Extant Yes
Anguilla (to UK) N Extant Yes
Antigua and Barbuda N Extant Yes
Aruba (to Netherlands) N Extant Yes
Australia N Extant Yes
Bahamas N Extant Yes
Barbados N Extant Yes
Belize N Extant Yes
Bermuda (to UK) N Extant Yes
Bonaire, Sint Eustatius and Saba (to Netherlands) N Extant Yes
Brazil N Extant Yes
Cape Verde N Extant Yes
Cayman Islands (to UK) N Extant Yes
Chile N Extant Yes
Christmas Island (to Australia) N Extant Yes
Cocos (Keeling) Islands (to Australia) N Extant Yes
Colombia N Extant Yes
Comoros N Extant Yes
Cook Islands N Extant Yes
Costa Rica N Extant Yes
Cuba N Extant Yes
Curaçao (to Netherlands) N Extant Yes
Dominica N Extant Yes
Dominican Republic N Extant Yes
Ecuador N Extant Yes
Egypt N Extant Yes
Eritrea N Extant Yes
Fiji N Extant Yes
French Polynesia N Extant Yes
Grenada V Extant Yes
Guadeloupe (to France) N Extant Yes
Guam (to USA) N Extant Yes
Guatemala N Extant Yes
Haiti N Extant Yes
Honduras U Extant
India N Extant Yes
Indonesia N Extant Yes
Iran, Islamic Republic of N Extant Yes
Jamaica N Extant Yes
Japan N Extant Yes
Kenya N Extant Yes
Kiribati N Extant Yes
Malaysia N Extant Yes
Maldives V Extant Yes
Marshall Islands N Extant Yes
Martinique (to France) N Extant Yes
Mauritius N Extant Yes
Mayotte (to France) N Extant Yes
Mexico N Extant Yes
Micronesia, Federated States of N Extant Yes
Montserrat (to UK) N Extant Yes
New Caledonia (to France) N Extant Yes
New Zealand N Extant Yes
Nicaragua N Extant Yes
Norfolk Island (to Australia) N Extant Yes
Northern Mariana Islands (to USA) N Extant Yes
Oman N Extant Yes
Pakistan N Extant Yes
Palau N Extant Yes
Panama N Extant Yes
Papua New Guinea N Extant Yes
Peru N Extant Yes
Philippines N Extant Yes
Pitcairn Islands (to UK) N Extant Yes
Puerto Rico (to USA) N Extant Yes
Réunion (to France) N Extant Yes
Samoa N Extant Yes
São Tomé e Príncipe N Extant Yes
Seychelles N Extant Yes
Sint Maarten (to Netherlands) N Extant Yes
Solomon Islands N Extant Yes
Somalia N Extant Yes
Spain V Extant Yes
Sri Lanka N Extant Yes
St Helena (to UK) N Extant Yes
St Kitts and Nevis N Extant Yes
St Lucia N Extant Yes
St Martin (to France) N Extant
St Vincent and the Grenadines N Extant Yes
Tanzania N Extant Yes
Thailand N Extant Yes
Tonga N Extant Yes
Trinidad and Tobago N Extant Yes
Turks and Caicos Islands (to UK) N Extant Yes
Tuvalu N Extant Yes
United Arab Emirates V Extant Yes
United States Minor Outlying Islands (to USA) N Extant Yes
USA N Extant Yes
Venezuela N Extant Yes
Vietnam N Extant
Virgin Islands (to UK) N Extant Yes
Virgin Islands (to USA) N Extant Yes
Wallis and Futuna Islands (to France) N Extant Yes
Yemen N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Anguilla (to UK) Dog Island
French Polynesia Clipperton
French Polynesia Clipperton Marine
Kiribati Enderbury Island
Kiribati Malden Island Marine
Kiribati McKean Island
Kiribati McKean Island Marine
Kiribati Phoenix Islands Marine
St Helena (to UK) Boatswainbird Island
St Helena (to UK) Letterbox Peninsula
United States Minor Outlying Islands (to USA) Baker Island
United States Minor Outlying Islands (to USA) Howland and Baker Marine
United States Minor Outlying Islands (to USA) Howland Island
United States Minor Outlying Islands (to USA) Jarvis Island
United States Minor Outlying Islands (to USA) Jarvis Island Marine
USA Northwestern Hawaiian Islands
Venezuela Isla La Blanquilla - Marine

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc major resident
Marine Intertidal Shingle and/or Pebble Shoreline and/or Beaches major resident
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   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species disturbance, Reduced reproductive success, Species mortality
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus rattus Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Reduced reproductive success

Recommended citation
BirdLife International (2019) Species factsheet: Sula dactylatra. Downloaded from http://www.birdlife.org on 16/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/06/2019.