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Location Trinidad and Tobago, Tobago
Central coordinates 60o 31.24' West  11o 21.15' North
IBA criteria A4i, A4ii, B4ii
Area 1,000 ha
Altitude 0 - 100m
Year of IBA assessment 2007

Site description St Giles Islands comprise one main island and several outlying rocks about one kilometer off the northeast of Tobago. The main island is roughly 29 ha of steeply sloping land rising to just over 100m. There is no habitation on the island and the topography makes such development unlikely. Seas around the island are generally rough and landing is hazardous.

Key Biodiversity St. Giles Islands are one of the most important seabird breeding colonies in the southern West Indies. They host the only breeding colonies of Magnificent Frigatebirds and Red-footed Boobies in Trinidad and Tobago. Audubon’s Shearwaters, Brown Boobies, Brown Noddies and Red-billed Tropicbirds also breed in considerable numbers. Up to 80 masked boobies have recently started roosting on one of the outlying rocks. Recent counts of seabird breeding populations are well below what was previously recorded. The alarmingly low numbers recently recorded may in part be due to insufficient sampling effort as the terrain and rough seas make counting very difficult. Seabirds continue to nest at a number of minor sites around Tobago and it is likely that with a cessation of poaching, St. Giles should remain a major breeding colony.

Non-bird biodiversity: The terrestrial fauna of St. Giles has not been studies but it may be similar to that of Little Tobago which houses the endemic Ocellated Gecko Gonatodes ocellatus and endemic subspecies of one lizard Bachia heteropa alleni and one snake Mastigodryas boddaerti dunni.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Puffinus lherminieri resident  1958-1968  100 breeding pairs  poor  B4ii  Not Recognised 
Red-billed Tropicbird Phaethon aethereus resident  1958-1968  100 breeding pairs  poor  A4i  Least Concern 
Magnificent Frigatebird Fregata magnificens breeding  2000  500-1,000 breeding pairs  poor  A4ii  Least Concern 
Sula dactylatra winter  2006  80 individuals  poor  B4ii  Not Recognised 
Red-footed Booby Sula sula breeding  2000  750 breeding pairs  poor  B4ii  Least Concern 
Brown Booby Sula leucogaster resident  1958-1968  50 breeding pairs  poor  B4ii  Least Concern 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
St. Giles Island Game Sanctuary 29 is identical to site 0  


IUCN habitat Habitat detail Extent (% of site)
Rocky areas   major
Sea Sea inlets  major
Shrubland Arid lowland scrub  -

Land use

Land-use Extent (% of site)
nature conservation and research major
tourism/recreation major
hunting -

Protection status The St. Giles Islands are formally listed as a game sanctuary but enforcement is minimal. The islands are however protected in part by their inhospitable terrain and hazardous waters.

Further web sources of information 

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

References Bacon, P.B. and R.P. ffrench (1972);Dinsmore, J.J. and ffrench, R.P. (1969);ffrench, R., (1991);Hayes, F. E., and S. Bodnar. (2007)

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: St Giles Islands. Downloaded from on 23/10/2016

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