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Location Aruba (to Netherlands)
Central coordinates 70o 2.35' West  12o 30.58' North
IBA criteria A4i
Area 309 ha
Altitude 0 - 1m
Year of IBA assessment 2007

Site description Two or more variably sized sand/boulder coral islets adjacent to the central harbor in Oranjestad and the east end of the bay under the flight path of the Queen Beatrice Airport. The islets are subject to considerable variation in size, shape and substrate following winter storms.

Key Biodiversity The islets represent the only alternative nest sites for Cayenne terns on Aruba. In most years the Cayenne terns are divided roughly 70% and 30% between San Nicolas Bay Reef Islands and the Oranjestad Reef Islands. Individually banded Cayenne tern chicks originally banded within San Nicolas Bay have been observed as nesting adults on the Oranjestad islets. Several instances of multiple movements back and forth between these two locations by the same birds in subsequent years have been observed. Up to 26 pairs of Common tern have nested on the islets.

Non-bird biodiversity: Marine turtles are occasionally observed in the surrounding waters, but with no evidence of nesting on the islets. The seaward side of these reef islands contain large (but not quantified) numbers of conch - a CITES protected species.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Sandwich Tern Thalasseus sandvicensis resident  2007  1,300 individuals  medium  A4i  Least Concern 
Common Tern Sterna hirundo breeding  2007  26 breeding pairs  medium  A4i  Least Concern 


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

Land use

Land-use Extent (% of site)
not utilised major

Protection status Uncertain protective status. However, the islands are patrolled by the coastguard and observed by the harbor authorities and the police.

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 A. J. del Nevo pers. comm.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Oranjestad Reef Islands. Downloaded from on 28/10/2016

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