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Year of most recent IBA criteria assessment: 2008

Populations of IBA trigger species

Species	Current IUCN Red List Category	Season	Year(s) of estimate	Population estimate	IBA Criteria Triggered
Greater Rhea Rhea americana	NT	resident	1991-1998	30 individuals	A1
Coscoroba Swan Coscoroba coscoroba	LC	resident	1991-1998	60-325 individuals	A4i
Black-necked Swan Cygnus melancoryphus	LC	resident	1987-1999	20-1,442 individuals	A4i
Buff-breasted Sandpiper Calidris subruficollis	NT	winter	1999	300 individuals	A1, A4i
Curve-billed Reedhaunter Limnornis curvirostris	LC	resident	1999	uncommon	A3
Straight-billed Reedhaunter Limnoctites rectirostris	NT	resident	1999-2008	90 individuals	A1, A2
Sulphur-throated Spinetail Cranioleuca sulphurifera	LC	resident	1999	present	A3
Bay-capped Wren-spinetail Spartonoica maluroides	NT	resident	1999	90 individuals	A1, A3
Black-and-white Monjita Xolmis dominicanus	VU	resident	1999	90 individuals	A1
Saffron-cowled Blackbird Xanthopsar flavus	EN	resident	1999-2007	90 individuals	A1
A4iii Species group - waterbirds	n/a	unknown	-	20,000-49,999 individuals	A4iii

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

Protected Area	Designation	Area (ha)	Relationship with IBA	Overlap with IBA (ha)
Laguna de Castillos	Paisaje Protegido	8,185	protected area contained by site	8,185
Humedales del Este	Other Area	260,000	protected area contains site	27,000
Cabo Polonio	Parque Nacional	25,820	protected area overlaps with site	0
Bañados del Este y Franja Costera	Ramsar Site, Wetland of International Importance	431,536	protected area overlaps with site	27,000
Bañados del Este y Franja Costera	UNESCO-MAB Biosphere Reserve	1,245,750	protected area contains site	0
Bañados del Este	UNESCO-MAB Biosphere Reserve	200,000	protected area contains site	27,000

IUCN Habitat	Habitat detail	Extent (% of site)
Grassland	Campo grassland	-
Wetlands (inland)	Salt/brackish marshes, Coastal lagoons	-

For further information about the habitat classification please click here.

Land-use	Extent (% of site)
rangeland/pastureland	-
tourism/recreation	-
fisheries/aquaculture	-

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

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Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Castillos Lagoon. Downloaded from http://www.birdlife.org on 15/08/2022.