|Location||Anguilla (to UK)|
|Central coordinates||63o 25.74' West 18o 36.37' North|
|IBA criteria||A4i, B4i, B4ii|
|Altitude||0 - 12m|
|Year of IBA assessment||2007|
Ornithological information 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.
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.
|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 Sterna anaethetus||breeding||1999-2005||270 breeding pairs||good||A4i||Least Concern|
|Brown Noddy Anous stolidus||breeding||1999||700 breeding pairs||good||B4i||Least Concern|
|Protected area||Designation||Area (ha)||Relationship with IBA||Overlap with IBA (ha)|
|Sombrero Island||Marine Park||0||unknown||0|
|IUCN habitat||Habitat detail||Extent (% of site)|
|Sea||Open Sea; Rock stacks & coastal islets; Sea cliffs & rocky shores||major|
|Land-use||Extent (% of site)|
|nature conservation and research||-|
Other 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.
Management considerations The island was formerly mined for phosphate leaving the surface pitted with craters up to 10 metres deep. A few stark buildings from the phosphate industry remain alongside those from Sombrero's long time use as a lighthouse station. Until recently the island was permanently inhabited by a small number of lighthouse staff who were transported by small boat across the 65km from mainland Anguilla. A new unmanned lighthouse was installed in 2002 limiting visitors to the occasional fisherman and biologists engaged in fieldwork. There is little vegetation on the island following Hurrican Luis in 1995 when an area of large cacti was destroyed. The vegetation of the island is now in an early stage of recovery. The principal threat to Sombrero's seabirds in recent years was an application in 1999 to build a satellite-launching station, though this has since been withdrawn.
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Recommended citation BirdLife International (2013) Important Bird Areas factsheet: Sombrero. Downloaded from http://www.birdlife.org on 19/06/2013
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