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The site was identified as internationally important for bird conservation in 2016 because it was regularly supporting significant populations of the species listed below, meeting IBA criteria.

Populations meeting IBA criteria ('key species') at the site:

Species	Red List	Season (year/s of estimate)	Size	IBA criteria
Tundra Swan Cygnus columbianus	LC	non-breeding (2011–2015)	624–1,507 individuals	B1i, C2, C6
Barnacle Goose Branta leucopsis	LC	non-breeding (2011–2015)	13,624–23,215 individuals	A4i, B1i, C2
Greater White-fronted Goose Anser albifrons	LC	non-breeding (2011–2015)	31,500–38,446 individuals	B1i, C3
Smew Mergellus albellus	LC	non-breeding (2011–2015)	446–763 individuals	B1i, C2, C6
Tufted Duck Aythya fuligula	LC	non-breeding (2011–2015)	12,324–18,218 individuals	B1i, C3
Gadwall Mareca strepera	LC	non-breeding (2011–2015)	15,655 individuals	B1i, C3
Eurasian Wigeon Mareca penelope	LC	non-breeding (2011–2015)	26,045–45,519 individuals	B1i, C3
Common Teal Anas crecca	LC	non-breeding (2011–2015)	7,928–12,054 individuals	B1i, C3
Eurasian Coot Fulica atra	LC	winter (2011–2015)	11,167–14,709 individuals	B2
Black-crowned Night Heron Nycticorax nycticorax	LC	breeding (2011–2015)	1 breeding pairs	C6
Great White Egret Ardea alba	LC	non-breeding (2011–2015)	453–961 individuals	C6
Pied Avocet Recurvirostra avosetta	LC	breeding (2011–2015)	192–408 breeding pairs	C6
Black-tailed Godwit Limosa limosa	NT	non-breeding (2011–2015)	2,517–4,196 individuals	B1i, C3
Black-headed Gull Larus ridibundus	LC	non-breeding (2011–2015)	81,530 individuals	A4i, B1i, C3
Osprey Pandion haliaetus	LC	non-breeding (2011–2015)	9–13 individuals	C6
White-tailed Sea-eagle Haliaeetus albicilla	LC	breeding (2011–2015)	1–2 breeding pairs	C6
White-tailed Sea-eagle Haliaeetus albicilla	LC	non-breeding (2011–2015)	4–6 individuals	C6
Common Kingfisher Alcedo atthis	LC	breeding (2011–2015)	22–33 breeding pairs	B2, C6
Peregrine Falcon Falco peregrinus	LC	breeding (2011–2015)	3–4 breeding pairs	C6
Sedge Warbler Acrocephalus schoenobaenus	LC	breeding (2011–2015)	1,024–1,313 breeding pairs	B3
Savi's Warbler Locustella luscinioides	LC	breeding (2011–2015)	57 breeding pairs	B3
Bluethroat Luscinia svecica	LC	breeding (2011–2015)	995–1,165 breeding pairs	C6
A4iii Species group - waterbirds	n/a	non-breeding (2011–2015)	113,256–225,739 individuals	A4iii, C4

Ideally the conservation status of the IBA will have been checked regularly since the site was first identified in 2016. The most recent assessment (2018) is shown below.

Pressure (threats to the key species and/or their habitats)
Threat	Timing	Scope	Severity	Result
Human intrusions and disturbance	happen­ing now	some of popul­ation/area (10–49%)	no deteri­oration (<1% over 3 gener­ations)	low
Energy production and mining	happen­ing now	few individ­uals/small area (<10%)	no deteri­oration (<1% over 3 gener­ations)	low

Response (conservation actions taken for the key species and/or their habitats)
Designation	Planning	Action	Result
Whole area of site (>90%) covered by appropriate conservation designation	A compre­hensive and appropriate manage­ment plan exists that aims to maintain or improve the popul­ations of qualify­ing bird species	Some limited conservation initiatives are in place	medium

Year	Protected Area	Designation (management category)	% coverage of IBA
-	Brabantse Biesbosch	Nature Conservation Law (-)	28
-	Dordtse Biesbosch	Nature Reserve (-)	9
-	Sliedrechtse Biesbosch	Nature Reserve (-)	8
1994	De Biesbosch	Nationaal Park (II)	92
1994	De Biesbosch	National Park (-)	75
1996	Biesbosch	Natuurbeschermingswet (IV)	100

Habitat	% of IBA	Habitat detail
Wetlands (inland)	45	Standing freshwater; Rivers and streams; Water fringe vegetation
Artificial/Terrestrial	39	Highly improved re-seeded landscapes
Forest	16	Alluvial and very wet forest

Land use	% of IBA
water management	100
hunting	50
nature conservation and research	49
tourism/recreation	35
agriculture	30
fisheries/aquaculture	30
urban/industrial/transport	16
water management	6
other	-

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Recommended citation
BirdLife International (2025) Important Bird Area factsheet: Biesbosch (Netherlands). Downloaded from https://datazone.birdlife.org/site/factsheet/biesbosch-iba-netherlands on 25/01/2025.