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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
European Nightjar Caprimulgus europaeus	LC	breeding	2004	365 males	B2, C6
Woodlark Lullula arborea	LC	resident	2006	220 males	C6
Dartford Warbler Curruca undata	NT	resident	2006	387 males	C6

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
Agricultural expansion and intensification	livestock farming and ranching (includes forest grazing) - small-holder grazing, ranching or farming	happening now	some of area/population (10-49%)	slow but significant deterioration	medium
Agricultural expansion and intensification	wood and pulp plantations (includes afforestation) - agro-industry plantations	happening now	small area/few individuals (<10%)	slow but significant deterioration	low
Agricultural expansion and intensification	wood and pulp plantations (includes afforestation) - agro-industry plantations	happening now	small area/few individuals (<10%)	slow but significant deterioration	low
Human intrusions and disturbance	war, civil unrest and military exercises	happening now	small area/few individuals (<10%)	slow but significant deterioration	low
Natural system modifications	other ecosystem modifications	happening now	some of area/population (10-49%)	slow but significant deterioration	medium
Residential and commercial development	housing and urban areas	happening now	some of area/population (10-49%)	moderate to rapid deterioration	high
Residential and commercial development	tourism and recreation areas	happening now	some of area/population (10-49%)	slow but significant deterioration	medium

Condition of key/trigger populations (state)
Scientific	Common	TargetPop	ActualPop	Units	Remaining	Result
Caprimulgus europaeus	European Nightjar	155	365	males	100	favourable
Lullula arborea	Woodlark	67	220	males	100	favourable
Curruca undata	Dartford Warbler	115	387	males	100	favourable

Conservation actions taken at site (response)
Conservation Designation	Management Planning	Conservation Action	Result
Most of site (50-90%) covered (including the most critical parts for important bird species)	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	medium

For more information about IBA monitoring please click here

Protected Area	Designation	Area (ha)	Relationship with IBA	Overlap with IBA (ha)
Whitmoor Common	Site of Special Scientific Interest (UK)	166	protected area overlaps with site	0
Whitmoor & Rickford Commons	Local Nature Reserve	185	protected area overlaps with site	0
West Minley Meadow	Site of Special Scientific Interest (UK)	4	protected area overlaps with site	0
Wasing Wood Ponds	Site of Special Scientific Interest (UK)	14	protected area overlaps with site	0
Thursley; Ash, Pirbright And Chobham	Site of Community Importance (Habitats Directive)	5,154	protected area overlaps with site	0
Thames Basin Heaths	Special Protection Area (Birds Directive)	8,311	protected area contained by site	8,275
Swinley Park and Brick Pits	Site of Special Scientific Interest (UK)	89	protected area overlaps with site	0
Snelsmore Common	Site of Special Scientific Interest (UK)	104	protected area overlaps with site	0
Smart's and Prey Heaths	Site of Special Scientific Interest (UK)	39	protected area overlaps with site	0
Sandhurst To Owlsmoor Bogs and Heaths	Site of Special Scientific Interest (UK)	86	protected area overlaps with site	0
Pamber Forest and Silchester Common	Site of Special Scientific Interest (UK)	342	protected area overlaps with site	0
Pamber Forest	Local Nature Reserve	190	protected area overlaps with site	0
Padworth Common	Local Nature Reserve	30	protected area overlaps with site	0
Ockham and Wisley Commons	Site of Special Scientific Interest (UK)	266	protected area overlaps with site	0
Ockham and Wisley	Local Nature Reserve	333	protected area overlaps with site	0
North Wessex Downs	Area of Outstanding Natural Beauty	173,228	protected area overlaps with site	0
King's Copse	Site of Special Scientific Interest (UK)	14	protected area is adjacent to site	0
Horsell Common	Site of Special Scientific Interest (UK)	152	protected area overlaps with site	0
Heath Brow	Site of Special Scientific Interest (UK)	2	protected area overlaps with site	0
Hazeley Heath	Nature Reserve	109	protected area overlaps with site	0
Hazeley Heath	Site of Special Scientific Interest (UK)	181	protected area overlaps with site	0
Greenham and Crookham Commons	Site of Special Scientific Interest (UK)	281	protected area overlaps with site	0
Foxlease and Ancells Meadows	Site of Special Scientific Interest (UK)	69	protected area is adjacent to site	0
Fox Corner	Local Nature Reserve	6	protected area overlaps with site	0
Finchampstead Ridges	Nature Reserve	55	protected area overlaps with site	0
Eelmoor Marsh	Site of Special Scientific Interest (UK)	66	protected area overlaps with site	0
Decoy Pit , Pools & Woods	Site of Special Scientific Interest (UK)	18	protected area overlaps with site	0
Colony Bog and Bagshot Heath	Site of Special Scientific Interest (UK)	1,131	protected area overlaps with site	1,127
Chobham Common	National Nature Reserve	520	protected area overlaps with site	0
Chobham Common	Site of Special Scientific Interest (UK)	656	protected area overlaps with site	651
Castle Bottom To Yateley Common and Hawley Commons	Site of Special Scientific Interest (UK)	923	protected area overlaps with site	0
Castle Bottom	National Nature Reserve	31	protected area overlaps with site	0
Broadmoor To Bagshot Woods and Heaths	Site of Special Scientific Interest (UK)	1,697	protected area overlaps with site	1,715
Brentmoor Heath	Local Nature Reserve	29	protected area overlaps with site	0
Bramshill	Site of Special Scientific Interest (UK)	674	protected area overlaps with site	0
Bourley and Long Valley	Site of Special Scientific Interest (UK)	824	protected area overlaps with site	820
Bisley & West End Commons	Local Nature Reserve	37	protected area overlaps with site	0
Basingstoke Canal	Site of Special Scientific Interest (UK)	101	protected area overlaps with site	0
Ash To Brookwood Heaths	Site of Special Scientific Interest (UK)	1,577	protected area overlaps with site	1,573

IUCN Habitat	Habitat detail	Extent (% of site)
Forest	Broadleaved deciduous woodland, Mixed woodland	-
Shrubland	Heathland	-
Grassland		-
Wetlands (inland)	Standing freshwater, Fens, transition mires and springs	-
Artificial/Terrestrial	Forestry plantations	-

For further information about the habitat classification please click here.

Land-use	Extent (% of site)
forestry	-
military	-
nature conservation and research	-
tourism/recreation	-
urban/industrial/transport	-

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

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Recommended citation
BirdLife International (2023) Important Bird Areas factsheet: Thames Basin Heaths. Downloaded from http://www.birdlife.org on 02/02/2023.