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Location Aruba (to Netherlands)
Central coordinates 69o 54.18' West  12o 25.26' North
IBA criteria A4i, B4i
Area 248 ha
Altitude 1 - 3m
Year of IBA assessment 2007

Site description Five small (1.75km2) low lying (max height 3m), boulder-coral reef islets located at the south-east corner of Aruba. The islands are located within San Nicolas Bay separated from the mainland by a shallow lagoon (3m-15m) adjacent to a large oil refinery and the town of San Nicolas. Hurricanes, winter storms and heavy rains have changed the size, substrate and extent of vegetative cover on the islands. Human disturbance and egg collecting has been minimized through public awareness and education. Informal protection provided by the refinery staff with regular patrols by the coastguard.

Key Biodiversity A significant regional site for Cayenne tern (1,300 – 3,500 prs.), black noddy (26-48 prs.) , roseate tern (25-75 prs.) and common tern (10-30 prs.). The site also includes sooty terns (2,000 - 6,600 prs.), brown noddy (120-180 prs.), bridled terns (3-150 prs.), least tern (5-85 prs.), and up to 10 prs of sandwich tern and royal tern. The timing of nesting is primarily between early April and mid-August, although black noddies may nest outside of this period.

Non-bird biodiversity: Aruban whiptail lizards Cnemidophorus arubensis have been recorded on the islets; turtles are occasionally seen in the waters surrounding the islands; they are not known to breed on the islets. Queen conch (Strombus gigas) is relatively abundant (but not quantified) south of the San Nicolas Bay Reef Islands.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Laughing Gull Larus atricilla resident  2007  800 individuals  good  A4i  Least Concern 
Royal Tern Thalasseus maximus breeding  2007  10 breeding pairs  good  B4i  Least Concern 
Sandwich Tern Thalasseus sandvicensis breeding  2007  1,300-3,500 breeding pairs  good  A4i  Least Concern 
Roseate Tern Sterna dougallii breeding  2007  25-75 breeding pairs  good  A4i  Least Concern 
Common Tern Sterna hirundo breeding  2007  10-30 breeding pairs  good  A4i  Least Concern 
Least Tern Sternula antillarum breeding  2007  5-85 breeding pairs  good  B4i  Least Concern 
Bridled Tern Onychoprion anaethetus breeding  2007  132 individuals  good  B4i  Least Concern 
Sooty Tern Onychoprion fuscatus breeding  2006  14,340 individuals  good  B4i  Least Concern 
Brown Noddy Anous stolidus breeding  2007  520 individuals  good  B4i  Least Concern 
Black Noddy Anous minutus breeding  2007  26-48 breeding pairs  good  B4i  Least Concern 


IUCN habitat Habitat detail Extent (% of site)
Coastline   major
Forest Mangrove  -

Land use

Land-use Extent (% of site)
nature conservation and research major

Protection status The islands were designated for protection in 1996.

Acknowledgements We are very thankful to the author of this information Dr. Adrian del Nevo, and Theo Wools and Facundo Franken for their review.

Further web sources of information 

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

References AES (2006 and 2007), Bridge et. al (2005),Halewyn (1985), Voous (1983)

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 (2016) Important Bird and Biodiversity Area factsheet: San Nicolas Bay Reef Islands. Downloaded from on 27/10/2016

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