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Location Anguilla (to UK)
Central coordinates 63o 25.74' West  18o 36.37' North
IBA criteria A4i, B4i, B4ii
Area 618 ha
Altitude 0 - 12m
Year of IBA assessment 2013





Site description A remote, 38 hectare flat-topped rocky outcrop lying 65 kilometres northwest of Anguilla. The cliffs and rocky areas are home to a large seabird colony and endemic ground lizard. The island is currently stark and bare following damage by Hurricane Luis in 1995 when large areas of cacti and other plants were destroyed. Extensive phosphate deposits were mined in the 19th and early 20th century leaving the surface pitted with craters up to 10 metres deep and the remains of industrial buildings. A manned lighthouse with associated buildings was in use until 2002 when it was replaced with an automated light.

Key Biodiversity At least 32 species are recorded on the island and several North American species of landbird have occurred as vagrants. The remote rocky outpost has long been important for breeding seabirds with confirmed reports of 14 species although only 7 species currently breed: Masked Booby (27 pairs), Brown Booby (386 pairs) Brown Noddy (700 pairs), Laughing Gull, Least Tern, Bridled Tern, and Sooty Tern. Species reported to have bred in the past 40 years but are no longer present are: Red-billed Tropicbird, Magnificent Frigatebird, Gull-billed Tern, Royal Tern, Sandwich Tern, Roseate Tern, and, Black Noddy. Audubon's Shearwater is suspected of breeding. Small numbers of shore birds are found on the island outside the breeding season when the Peregrine Falcon is often present.

Non-bird biodiversity: The island is noted for the endemic critically endangered Sombrero Ground Lizard Ameiva corvina, a widespread and easily seen species on the island. A recently discovered dwarf gecko Sphaerodactylus sp.has been tentatively named Sombrero dwarf gecko. The tree lizard Anolis gingivinus is also found on the island.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Brown Booby Sula leucogaster breeding  2000  350-400 breeding pairs  medium  B4ii  Least Concern 
Bridled Tern Onychoprion anaethetus breeding  1999-2005  270 breeding pairs  good  A4i  Least Concern 
Brown Noddy Anous stolidus breeding  1999  700 breeding pairs  good  B4i  Least Concern 

IBA Monitoring

2013 high not assessed negligible
unset
Good - based on reliable and complete / representative data

Climate change and severe weather drought happening now whole area/population (>90%) slow but significant deterioration high
Climate change and severe weather habitat shifting and alteration likely in long term (beyond 4 years) whole area/population (>90%) moderate to rapid deterioration high
Climate change and severe weather storms and floods happening now whole area/population (>90%) slow but significant deterioration high
Climate change and severe weather temperature extremes likely in long term (beyond 4 years) whole area/population (>90%) very rapid to severe deterioration high
Energy production and mining mining and quarrying past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Energy production and mining renewable energy happening now small area/few individuals (<10%) no or imperceptible deterioration low
Geological events earthquakes/tsunamis happening now small area/few individuals (<10%) slow but significant deterioration low
Human intrusions and disturbance recreational activities happening now small area/few individuals (<10%) no or imperceptible deterioration low
Human intrusions and disturbance work and other activities past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Natural system modifications other ecosystem modifications happening now small area/few individuals (<10%) no or imperceptible deterioration low
Over-exploitation, persecution and control of species direct mortality of trigger species - hunting and trapping happening now small area/few individuals (<10%) slow but significant deterioration low
Over-exploitation, persecution and control of species direct mortality of trigger species - persecution/control past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Pollution light pollution past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Residential and commercial development commercial and industrial development past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Residential and commercial development housing and urban areas past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Transportation and service corridors roads and railroads past (and unlikely to return) and no longer limiting small area/few individuals (<10%) no or imperceptible deterioration low
Transportation and service corridors shipping lanes happening now small area/few individuals (<10%) no or imperceptible deterioration low

Sula dactylatra Masked Booby 12 12 individuals 100 favourable
Onychoprion anaethetus Bridled Tern 120 120 individuals 100 favourable
Anous stolidus Brown Noddy 280 280 individuals 100 favourable

Little/none of site covered (<10%)  No management planning has taken place  Very little or no conservation action taking place  negligible 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Sombrero Island Marine Park 0 protected area contained by site 0  

Habitats

IUCN habitat Habitat detail Extent (% of site)
Sea Open sea; Pelagic waters  major
Shrubland Arid lowland scrub  minor
Coastline Sea cliffs & rocky shores; Shallow marine areas, coral reefs & keys  major

Land use

Land-use Extent (% of site)
urban/industrial/transport major
Notes: lighthouse, boats
fisheries/aquaculture major
nature conservation and research major

Further web sources of information 

Site profile from Important Bird Areas in the Caribbean: key sites for conservation (BirdLife International 2008)

Contribute  Please click here to help BirdLife conserve the world's birds - your data for this IBA and others are vital for helping protect the environment.

Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Sombrero. Downloaded from http://www.birdlife.org on 26/11/2014

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