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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') at the site:

Species	Red List1	Season	Year(s)	Size	IBA criteria
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	VU	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	NT	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 Luscinia svecica	LC	winter	2001	frequent	C6
A4iii Species group - waterbirds	n/a	winter	2002	50-249 individuals	A4iii, C4

1. The current IUCN Red List category. The category at the time of the IBA criteria assessment (2002) may differ.

Ideally the conservation status of the IBA will have been checked regularly since the site was first identified in 2002. The most recent assessment (2020) is shown below.

Pressure (threats to the trigger species and/or their habitats)
Threat	Timing	Scope	Severity	Result
Invasive and other problematic species and genes	happening now	majority/most of area/population (50-90%)	slow but significant deterioration	high
Natural system modifications	happening now	some of area/population (10-49%)	slow but significant deterioration	medium
Pollution	happening now	some of area/population (10-49%)	slow but significant deterioration	medium
Transportation and service corridors	happening now	small area/few individuals (<10%)	very rapid to severe deterioration	low
Residential and commercial development	happening now	small area/few individuals (<10%)	very rapid to severe deterioration	low
Biological resource use	happening now	small area/few individuals (<10%)	very rapid to severe deterioration	low
Agricultural expansion and intensification	likely in long term (beyond 4 years)	small area/few individuals (<10%)	moderate to rapid deterioration	low
Climate change and severe weather	happening now	small area/few individuals (<10%)	slow but significant deterioration	low
Human intrusions and disturbance	happening now	some of area/population (10-49%)	no or imperceptible deterioration	low

Response (conservation actions taken for the trigger species and/or their habitats)
Protected areas	Management plan	Other action	Result
Not assessed	Not assessed	Not assessed	not assessed

Year	Protected Area	Designation	% overlap with IBA
1976	Estuário do Tejo	Reserva Natural	31
1980	Estuário do Tejo	Ramsar Site, Wetland of International Importance	32
1988	Estuário do Tejo	Special Protection Area (Birds Directive)	100
1997	Estuário do Tejo	Site of Community Importance (Habitats Directive)	97

Habitat1	Habitat detail	% of IBA
Artificial/Terrestrial	Arable land, Forestry plantations	20
Forest	Broadleaved evergreen woodland	15
Marine Coastal/Supratidal		-
Marine Intertidal		-
Marine Neritic		-

1. IUCN Habitat classification.

Land use	% of IBA
agriculture	-
fisheries/aquaculture	-
forestry	-
hunting	-
nature conservation and research	-
urban/industrial/transport	-
water management	-

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Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Tejo estuary (Portugal). Downloaded from https://datazone.birdlife.org/site/factsheet/tejo-estuary-iba-portugal on 22/11/2024.