Tejo estuary

IBA Criteria

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 estimate IBA Criteria Triggered
Greylag Goose Anser anser LC winter 2002 2,500-4,350 individuals A4i, B1i, C3
Eurasian Wigeon Mareca penelope LC winter 2002 2,100-9,950 individuals A4i, B1i, C3
Common Teal Anas crecca LC winter 2002 4,800-25,500 individuals A4i, B1i, C3
Greater Flamingo Phoenicopterus roseus LC winter 2002 450-6,000 individuals A4i, B1i, C2, C6
European Nightjar Caprimulgus europaeus LC breeding 2001 frequent C6
Little Bustard Tetrax tetrax NT winter 2001 140-150 unknown A1, C1, C6
White Stork Ciconia ciconia LC resident 2001 50-100 breeding pairs B2, C6
Eurasian Spoonbill Platalea leucorodia LC winter 2002 90-190 individuals A4i, B1i, C6
Common Little Bittern Ixobrychus minutus LC breeding 2001 rare C6
Purple Heron Ardea purpurea LC breeding 2000 150-200 breeding pairs A4i, B1i, B2, C6
Little Egret Egretta garzetta LC resident 2002 common C6
Pied Avocet Recurvirostra avosetta LC winter 2002 3,950-8,600 individuals A4i, B1i, B2, C2, C6
Black-winged Stilt Himantopus himantopus LC breeding 1996 500-750 breeding pairs C6
Grey Plover Pluvialis squatarola LC winter 2002 1,200-3,150 individuals A4i, B1i, C3
Kentish Plover Charadrius alexandrinus LC winter 2002 640-2,500 individuals A4i, B1i, C3
Kentish Plover Charadrius alexandrinus LC breeding 2002 150-200 breeding pairs B2
Black-tailed Godwit Limosa limosa NT winter 2002 30,000-80,000 individuals A4i, B1i, B2, C3
Dunlin Calidris alpina LC winter 2002 6,000-23,500 individuals A4i, B1i, B2, C3
Collared Pratincole Glareola pratincola LC breeding 2000 100-250 breeding pairs A4i, B1i, B2, C2, C6
Little Tern Sternula albifrons LC breeding 2002 12-19 breeding pairs C6
Common Barn-owl Tyto alba LC winter 2002 abundant B2
Short-eared Owl Asio flammeus LC winter 2002 14-40 individuals C6
Black-winged Kite Elanus caeruleus LC resident 1996 6-10 breeding pairs B2, C6
Booted Eagle Hieraaetus pennatus LC breeding 1996 5-10 breeding pairs C6
Western Marsh-harrier Circus aeruginosus LC breeding 2001 29-32 breeding pairs C6
Western Marsh-harrier Circus aeruginosus LC winter 1999 142-165 individuals C6
Montagu's Harrier Circus pygargus LC breeding 2001 2-3 breeding pairs C6
Calandra Lark Melanocorypha calandra LC resident 2002 frequent C6
Greater Short-toed Lark Calandrella brachydactyla LC breeding 2002 common C6
Bluethroat Cyanecula svecica LC winter 2001 frequent C6
A4iii Species group - waterbirds n/a winter 2002 50-249 individuals A4iii, C4

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

IBA Monitoring

Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2005 low not assessed not assessed
Was the whole site covered? No State assessed by unset
Accuracy of information good

Threats to the site (pressure)
Threat Level 1 Threat Level 2 Timing Scope Severity Result
Transportation and service corridors utility & service lines happening now small area/few individuals (<10%) very rapid to severe deterioration low

Conservation actions taken at site (response)
Conservation Designation Management Planning Conservation Action Result
Not assessed Not assessed Not assessed not assessed
For more information about IBA monitoring please click here

IBA Protection

Protection status:

Protected Area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)
Estuário do Tejo Special Protection Area (Birds Directive) 44,772 is identical to site 44,362
Estuário do Tejo Site of Community Importance (Habitats Directive) 44,011 protected area contained by site 43,747
Estuário do Tejo Ramsar Site, Wetland of International Importance 14,563 protected area contained by site 14,563
Estuário do Tejo Reserva Natural 14,416 protected area contained by site 14,192


IUCN Habitat Habitat detail Extent (% of site)
Forest Broadleaved evergreen woodland -
Wetlands (inland) Water fringe vegetation, Rivers and streams -
Artificial/Terrestrial Arable land, Forestry plantations -
Coastline Tidal rivers & enclosed tidal waters, Salt marshes, Mud flats & sand flats, Lagoons -
For further information about the habitat classification please click here.

Land use

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

Recommended citation
BirdLife International (2020) Important Bird Areas factsheet: Tejo estuary. Downloaded from on 16/07/2020.