Sado estuary

IBA Justification

Year of most recent IBA criteria assessment: 2002

Populations of IBA trigger species
Species Current IUCN Red List Category Season Year(s) of estimate Population at site IBA criteria triggered
White Stork Ciconia ciconia LC resident 1996 50-70 breeding pairs C6
Common Little Bittern Ixobrychus minutus LC breeding 1996 common C6
Purple Heron Ardea purpurea LC breeding 2002 15 breeding pairs B2, C6
Little Egret Egretta garzetta LC non-breeding 1996 common C6
Great Cormorant Phalacrocorax carbo LC winter 1996 1,000-2,200 individuals B1i, C3
Pied Avocet Recurvirostra avosetta LC winter 1996 2,000-4,000 individuals A4i, B1i, B2, C2
Black-winged Stilt Himantopus himantopus LC breeding 1996 200-800 breeding pairs A4i, B1i, C2, C6
Black-tailed Godwit Limosa limosa NT winter 1996 2,000-11,000 individuals B1i, C3
Dunlin Calidris alpina LC winter 1996 12,000-16,000 individuals B1i, B2, C3
Collared Pratincole Glareola pratincola LC breeding 1996 5-20 breeding pairs C6
Little Tern Sternula albifrons LC breeding 1996 50-100 breeding pairs B2, C6
Western Marsh-harrier Circus aeruginosus LC resident 1996 5-6 breeding pairs C6
A4iii Species group - waterbirds n/a winter 1996 20,000 individuals A4iii, C4

Note: The current IUCN Red List category may differ from the category that was valid at the time of IBA criteria assessment.

For more information about the IBA criteria, please click here

IBA Protection

Protected area (PA) PA designation PA area (ha) Relationship of PA with IBA Overlap of PA with IBA (ha)
Estuário do Sado Ramsar Site, Wetland of International Importance 25,588 protected area overlaps with site 24,633
Estuário do Sado Special Protection Area (Birds Directive) 24,633 protected area overlaps with site 24,312
Estuário do Sado Reserva Natural 23,971 protected area overlaps with site 20,011
Estuário do Sado Site of Community Importance (Habitats Directive) 30,968 protected area overlaps with site 23,346
Comporta / Galé Site of Community Importance (Habitats Directive) 32,051 protected area is adjacent to site 0
Açude da Murta Special Protection Area (Birds Directive) 498 protected area overlaps with site 0


IUCN Habitat Habitat detail Extent (% of site)
Forest Mixed woodland, Broadleaved evergreen woodland -
Shrubland Sclerophyllous scrub, garrigue and maquis -
Artificial/Terrestrial Arable land, Forestry plantations, Other urban and industrial areas -
Marine Neritic -
Marine Intertidal -
Marine Coastal/Supratidal -
For further information about the IUCN habitat classification, please click here.

Land use

Land-use Extent (% of site)
agriculture -
fisheries/aquaculture -
forestry -
hunting -
nature conservation and research -
tourism/recreation -
urban/industrial/transport -
For further information about the land-use classification, please click here.

Recommended citation
BirdLife International (2023) Important Bird Area factsheet: Sado estuary. Downloaded from on 06/06/2023.