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• Text account
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• Reference and further resources

The site was identified as important 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 List1	Season	Year(s)	Size	IBA criteria
Barnacle Goose Branta leucopsis	LC	breeding	2009-2014	1,181 breeding pairs	B3, C2, C6
Eurasian Bittern Botaurus stellaris	LC	breeding	2011-2015	11 breeding pairs	C6
Northern Lapwing Vanellus vanellus	NT	winter	2011-2015	4,357 individuals	B2
Black-tailed Godwit Limosa limosa	NT	non-breeding	2011-2015	2,032-2,465 individuals	B1i, C3
Ruff Calidris pugnax	LC	breeding	2011-2015	2 breeding pairs	C6
A4iii Species group - waterbirds	n/a	non-breeding	2011-2015	29,063-36,628 individuals	A4iii, C4

1. The current IUCN Red List category. The category at the time of the IBA criteria assessment (2016) may differ.

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	majority/most of area/population (50-90%)	slow but significant deterioration	high
Agricultural expansion and intensification	happening now	some of area/population (10-49%)	slow but significant deterioration	medium

Response (conservation actions taken for the trigger species and/or their habitats)
Protected areas	Management plan	Other 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	The conservation measures needed for the site are being comprehensively and effectively implemented	high

Year	Protected Area	Designation	% overlap with IBA
-	Wormer- En Jisperveld	Nature Reserve	37
2000	Wormer- en Jisperveld & Kalverpolder	Special Protection Area (Birds Directive)	100
2002	Wormer- en Jisperveld & Kalverpolder	Site of Community Importance (Habitats Directive)	86
2005	Wormer- en Jisperveld & Kalverpolder	Natuurbeschermingswet	100

Habitat1	Habitat detail	% of IBA
Artificial/Terrestrial	Highly improved re-seeded landscapes	83
Wetlands (inland)	Standing freshwater, Water fringe vegetation	17

1. IUCN Habitat classification.

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 23/11/2024.