Skokholm and Skomer

IBA Criteria

Year of most recent IBA criteria assessment: 2007

Populations of IBA trigger species
Species Current IUCN Red List Category Season Year(s) of estimate Population estimate IBA Criteria Triggered
European Storm-petrel Hydrobates pelagicus LC breeding 2000-2001 2,560 breeding pairs B2, C6
Manx Shearwater Puffinus puffinus LC breeding 1998 151,000 breeding pairs A4ii, B1ii, B2, C3
Lesser Black-backed Gull Larus fuscus LC breeding 1999-2004 15,049 breeding pairs A4i, B1i, B3, C3
Razorbill Alca torda NT breeding 1999-2004 5,398 breeding pairs B3
Short-eared Owl Asio flammeus LC breeding 1999-2004 2 breeding pairs B2, C6
Red-billed Chough Pyrrhocorax pyrrhocorax LC resident 1999-2004 4-5 breeding pairs C6
A4iii Species group - seabirds n/a breeding 1999-2001 177,257 breeding pairs A4iii, C4
A4iii Species group - waterbirds n/a breeding 1999-2001 15,736 breeding pairs A4iii, C4

Note: This table presents the IBA criteria triggered and the species that triggered then at the time of assessment, the current IUCN Red List category may vary from that which was in place at that time.

For more information about the IBA assessment process and criteria please click here

IBA Monitoring

Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2007 high unfavourable low
Was the whole site covered? Yes State assessed by Population
Accuracy of information good

Threats to the site (pressure)
Threat Level 1 Threat Level 2 Timing Scope Severity Result
Biological resource use fishing & harvesting aquatic resources - unintentional effects: large scale happening now whole area/population (>90%) slow but significant deterioration high
Climate change and severe weather habitat shifting and alteration likely in long term (beyond 4 years) majority/most of area/population (50-90%) moderate to rapid deterioration medium
Energy production and mining renewable energy likely in long term (beyond 4 years) some of area/population (10-49%) slow but significant deterioration medium
Human intrusions and disturbance recreational activities likely in short term (within 4 years) some of area/population (10-49%) moderate to rapid deterioration medium

Condition of key/trigger populations (state)
Scientific Common TargetPop ActualPop Units Remaining Result
Hydrobates pelagicus European Storm-petrel 4400 2560 breeding pairs 59 unfavourable
Puffinus puffinus Manx Shearwater 157000 151000 breeding pairs 97 favourable
Larus fuscus Lesser Black-backed Gull 18500 15049 breeding pairs 82 near favourable
Alca torda Razorbill 2870 5398 breeding pairs 100 favourable
Asio flammeus Short-eared Owl 15 2 breeding pairs 14 not assessed
Pyrrhocorax pyrrhocorax Red-billed Chough 5 5 breeding pairs 100 favourable
Species group - waterbirds A4iii 21776 15736 breeding pairs 73 near favourable
Species group - seabirds A4iii 175954 177257 breeding pairs 100 favourable

Conservation actions taken at site (response)
Conservation Designation Management Planning Conservation Action Result
Whole area of site (>90%) covered by appropriate conservation designation No management plan exists but the management planning process has begun Some limited conservation initiatives are in place low
For more information about IBA monitoring please click here

IBA Protection

Protection status:

Protected Area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)
Skomer Island & Middleholm Site of Special Scientific Interest (GB) 314 protected area contained by site 316
Skomer Island National Nature Reserve 315 protected area contained by site 307
Skomer Marine Nature Reserve 1,318 protected area overlaps with site 22
Skokholm and Skomer Special Protection Area (Birds Directive) 24,188 is identical to site 422
Skokholm Site of Special Scientific Interest (GB) 107 protected area contained by site 106
Pembrokeshire Marine/ Sir Benfro Forol Site of Community Importance (Habitats Directive) 138,069 protected area overlaps with site 91
Pembrokeshire Coast National Park 58,400 protected area contains site 427
Marloes and Dale Heritage Coast 0 protected area contains site 427


IUCN Habitat Habitat detail Extent (% of site)
Shrubland Heathland -
Grassland -
Wetlands (inland) Standing freshwater, Water fringe vegetation, Fens, transition mires and springs -
Coastline Sea cliffs and rocky shores, Scree and boulders -
For further information about the habitat classification please click here.

Recommended citation
BirdLife International (2020) Important Bird Areas factsheet: Skokholm and Skomer. Downloaded from on 25/01/2020.