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Location United Kingdom, Wales
Central coordinates 5o 28.79' West  51o 43.85' North
IBA criteria A4ii, A4iii, B1ii, B2, C3, C4
Area 11 ha
Altitude 0 - 15m
Year of IBA assessment 2007

Royal Society for the Protection of Birds



Site description A low-lying, flat-topped basalt island situated about 18 km west of the mainland Dyfed coast. Vegetation is limited by exposure to wind, salt spray and the large numbers of seabirds. The site is important for its seabird colonies, including a very large gannetry.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Northern Gannet Morus bassanus breeding  2004  32,094 breeding pairs  poor  A4ii, B1ii, B2, C3  Least Concern 
A4iii Species group - seabirds breeding  1999-2001  31,611 breeding pairs  poor  A4iii, C4   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Grassholm Birds Directive 11 is identical to site 11  
Grassholm National Nature Reserve 11 is identical to site 11  
Grassholm RSPB Reserve 11 is identical to site 11  
Grassholm/ynys Gwales Site of Special Scientific Interest 11 is identical to site 9  
Pembrokeshire Coast National Park National Park 0 protected area contains site 11  
Pembrokeshire Marine/Sir Benfro Forol Habitats Directive 132,174 protected area contains site 11  

Habitats

IUCN habitat Habitat detail Extent (% of site)
Grassland   -
Coastline Rock stacks and islets; Sea cliffs and rocky shores  -

Land use

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

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Grassholm. Downloaded from http://www.birdlife.org on 19/09/2014

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