• Summary
• Text account
• Data table and detailed info
• Map
• Reference and further resources

The site was identified as important in 2007 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species') at the site:

Species	Red List1	Season	Year(s)	Size	IBA criteria
Northern Gannet Morus bassanus	LC	breeding	2004	32,094 breeding pairs	A4ii, B1ii, B2, C3
A4iii Species group - seabirds	n/a	breeding	1999-2001	31,611 breeding pairs	A4iii, C4

1. The current IUCN Red List category. The category at the time of the IBA criteria assessment (2007) may differ.

Ideally the conservation status of the IBA will have been checked regularly since the site was first identified in 2007. The most recent assessment (2007) is shown below.

State (condition of the trigger species' populations)
Species	Reference	Actual	Units	% remaining	Result
Northern Gannet Morus bassanus	33,000	32,094	breeding pairs	98	favourable
A4iii Species group - seabirds	33,510	31,611	breeding pairs	95	favourable

Pressure (threats to the trigger species and/or their habitats)
Threat	Timing	Scope	Severity	Result
Biological resource use	happening now	whole area/population (>90%)	slow but significant deterioration	high
Climate change and severe weather	likely in long term (beyond 4 years)	majority/most of area/population (50-90%)	moderate to rapid deterioration	medium

Response (conservation actions taken for the trigger species and/or their habitats)
Protected areas	Management plan	Other 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	Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity	high

Year	Protected Area	Designation	% overlap with IBA
-	Grassholm	RSPB Reserve	100
1948	Grassholm	Nature Reserve	55
1952	Pembrokeshire Coast	National Park	100
1954	Grassholm/Ynys Gwales	Site of Special Scientific Interest (UK)	82
1992	Grassholm	Special Protection Area (Birds Directive)	100
1996	Grassholm Island	National Nature Reserve	100
1997	Pembrokeshire Marine/ Sir Benfro Forol	Site of Community Importance (Habitats Directive)	100
2005	Pembrokeshire Marine / Sir Benfro Forol	Marine Protected Area (OSPAR)	36
2015	Grassholm	Marine Protected Area (OSPAR)	45
2017	West Wales Marine / Gorllewin Cymru Forol	Site of Community Importance (Habitats Directive)	100

Habitat1	Habitat detail	% of IBA
Grassland		-
Marine Coastal/Supratidal		-

1. IUCN Habitat classification.

Land use	% of IBA
nature conservation and research	-
tourism/recreation	-

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Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Grassholm (United Kingdom). Downloaded from https://datazone.birdlife.org/site/factsheet/grassholm-iba-united-kingdom on 23/11/2024.