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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
Leach's Storm-petrel Hydrobates leucorhous	VU	breeding	1999	45,433 breeding pairs	B1i, B2, C2, C6
Northern Fulmar Fulmarus glacialis	LC	breeding	1999	68,448 breeding pairs	A4ii, B1ii, C3
Northern Gannet Morus bassanus	LC	breeding	1999	61,340 breeding pairs	A4ii, B1ii, B2, C3
Great Skua Catharacta skua	LC	breeding	1999	168 breeding pairs	A4ii, B1ii, B3, C3
Atlantic Puffin Fratercula arctica	VU	breeding	1999	143,264 breeding pairs	A4ii, B1ii, B2, C3
Razorbill Alca torda	LC	breeding	1999	1,689 individuals	B3
A4iii Species group - seabirds	n/a	breeding	1999	341,941 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

Threats to the site (pressure)
Threat Level 1	Threat Level 2	Timing	Scope	Severity	Result
Climate change and severe weather	habitat shifting and alteration	happening now	whole area/population (>90%)	slow but significant deterioration	high

Condition of key/trigger populations (state)
Scientific	Common	TargetPop	ActualPop	Units	Remaining	Result
Hydrobates leucorhous		3200	45433	breeding pairs	100	favourable
Fulmarus glacialis	Northern Fulmar	63000	68448	breeding pairs	100	favourable
Morus bassanus	Northern Gannet	60500	61340	breeding pairs	100	favourable
Catharacta skua	Great Skua	145	168	breeding pairs	100	favourable
Fratercula arctica	Atlantic Puffin	130000	143264	breeding pairs	100	favourable
Alca torda	Razorbill	3821	1689	individuals	45	unfavourable
Species group - seabirds	A4iii	275738	341941	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	A comprehensive and appropriate management plan exists that aims to maintain or improve the populations of qualifying bird species	The conservation measures needed for the site are being comprehensively and effectively implemented	high

For more information about IBA monitoring please click here

Protected Area	Designation	Area (ha)	Relationship with IBA	Overlap with IBA (ha)
St Kilda	Site of Special Scientific Interest (UK)	870	protected area overlaps with site	853
St Kilda	Marine Protected Area (OSPAR)	0	protected area overlaps with site	0
St Kilda	Special Protection Area (Birds Directive)	29,015	protected area contains site	860
St Kilda	Marine Protected Area (OSPAR)	0	protected area overlaps with site	0
St Kilda	National Nature Reserve	872	protected area overlaps with site	853
St Kilda	World Heritage Site (natural or mixed)	24,201	protected area contains site	860
St Kilda	UNESCO-MAB Biosphere Reserve	865	is identical to site	860
St Kilda	Site of Community Importance (Habitats Directive)	25,468	protected area contains site	860
St Kilda	National Scenic Area	6,966	protected area contains site	0

IUCN Habitat	Habitat detail	Extent (% of site)
Shrubland	Heathland	-
Grassland	Humid grasslands	-
Coastline	Rock stacks and islets	-
Artificial/Terrestrial	Other urban and industrial areas	-
Marine Coastal/Supratidal		-

For further information about the habitat classification please click here.

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

For further information about the land use classification please click here.

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Recommended citation
BirdLife International (2023) Important Bird Areas factsheet: St Kilda. Downloaded from http://www.birdlife.org on 28/01/2023.