Salinas de Alverca e do Forte da Casa This is an IBA in Danger! 

IBA Justification

The site was identified as important in 2002 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species'):
Species Current IUCN Red List Category Season Year(s) Population estimate at site IBA criteria met
Greater Flamingo Phoenicopterus roseus LC winter 2000 1-100 individuals C6
Purple Heron Ardea purpurea LC breeding 2001 common C6
Pied Avocet Recurvirostra avosetta LC resident 2001 1-2 breeding pairs C6
Pied Avocet Recurvirostra avosetta LC winter 2001 10-100 individuals C6
Black-winged Stilt Himantopus himantopus LC resident 2001 40-300 breeding pairs C6
Black-winged Stilt Himantopus himantopus LC winter 2001 1-50 individuals C6
Collared Pratincole Glareola pratincola LC breeding 2001 10-40 breeding pairs B2, C6
Little Tern Sternula albifrons LC breeding 2000 frequent C6
Western Marsh-harrier Circus aeruginosus LC resident 1998 common C6

The current IUCN Red List category may differ from that which was valid at the time of IBA criteria assessment (2002).

IBA Conservation

IBA conservation assessment
Year of assessment (most recent) State (condition) Pressure (threat) Response (action)
2017 not assessed very high not assessed
Was the whole site assessed? State assessed by Accuracy of information
yes unset good

Pressure (threats to the trigger species and/or their habitats)
Threat level 1 Threat level 2 Timing Scope Severity Result
Residential and commercial development commercial and industrial development happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high
Transportation and service corridors roads and railroads likely in short term (within 4 years) some of area/population (10-49%) moderate to rapid deterioration medium

Response (conservation actions taken for the trigger species and/or their habitats)
Protected-area designation Management planning Other conservation action Result
Little/none of site covered (<10%) No management planning has taken place Very little or no conservation action taking place not assessed
For more information about IBA conservation status, 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 Tejo Site of Community Importance (Habitats Directive) 44,011 protected area is adjacent to site 0
Estuário do Tejo Special Protection Area (Birds Directive) 44,772 protected area overlaps with site 16


Habitat (IUCN level 1) Habitat detail Extent (% of site)
Artificial/Aquatic & Marine -
Artificial/Terrestrial Arable land, Other urban and industrial areas -
Shrubland Sclerophyllous scrub, garrigue and maquis -
Marine Coastal/Supratidal -
For more information about the IUCN Habitat classification, please click here.

Land use

Land-use Extent (% of site)
agriculture -
hunting -
military -
tourism/recreation -
urban/industrial/transport -
water management -

Recommended citation
BirdLife International (2023) Important Bird Area factsheet: Salinas de Alverca e do Forte da Casa. Downloaded from on 25/09/2023.