• Summary
• Text account
• Data table and detailed info
• Map
• Reference and further resources

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 ('triggering') IBA criteria.

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

Species	Red List	Season (year/s of estimate)	Size	IBA criteria
Barnacle Goose Branta leucopsis	LC	breeding (2009–2014)	1,181 pairs	B3, C2, C6
Eurasian Bittern Botaurus stellaris	LC	breeding (2011–2015)	11 pairs	C6
Northern Lapwing Vanellus vanellus	NT	winter (2011–2015)	4,357 birds	B2
Black-tailed Godwit Limosa limosa	NT	non-breeding (2011–2015)	2,032–2,465 birds	B1i, C3
Ruff Calidris pugnax	LC	breeding (2011–2015)	2 pairs	C6
A4iii Species group - waterbirds	n/a	non-breeding (2011–2015)	29,063–36,628 birds	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 trigger species and/or their habitats)
Threat	Timing	Scope	Severity	Result
Natural system modifications	happe­ning now	most of popul­ation/area (50–90%)	slow decline (1–10% over 3 gener­ations)	high
Agricultural expansion and intensification	happe­ning now	some of popul­ation/area (10–49%)	slow decline (1–10% over 3 gener­ations)	medium

Response (conservation actions taken for the trigger species and/or their habitats)
Designation	Planning	Action	Result
Whole area (>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	The conservation measures needed for the site are being compre­hensively and effectively implemented	high

Year	Protected Area	Designation (management category)	% coverage of IBA
-	Wormer- En Jisperveld	Nature Reserve (IV)	37
2005	Wormer- en Jisperveld & Kalverpolder	Natuurbeschermingswet (IV)	100

Habitat	% of IBA	Habitat detail
Artificial/Terrestrial	83	Highly improved re-seeded landscapes
Wetlands (inland)	17	Standing freshwater; Water fringe vegetation

Land use	% of IBA
water management	100
nature conservation and research	32
agriculture	25
tourism/recreation	11
fisheries/aquaculture	10
hunting	10

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Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Wormer- en Jisperveld & Kalverpolder (Netherlands). Downloaded from https://datazone.birdlife.org/site/factsheet/wormer-en-jisperveld-&-kalverpolder-iba-netherlands on 28/12/2024.