c46d695c-bc44-439c-8645-cb04ef4cfe5d https://ipt.biodiversity.be/resource?r=zwin-park-butterflies-observations Wouter Faveyts Zwin Natuur Park Scientific collaborator

West Flanders BE

wouter.faveyts@west-vlaanderen.be https://www.zwin.be/ Wouter Faveyts Zwin Natuur Park Scientific collaborator

West Flanders BE

wouter.faveyts@west-vlaanderen.be https://www.zwin.be/ Stijn Cooleman Belgian Biodiversity Platform Biodiversity Data Officer

BE

s.cooleman@biodiversity.be 0000-0003-3029-0451 2025-08-01 eng This survey dataset contains occurrence data on butterflies observed and counted along transects within the Zwin Nature Park (ZNP) at Knokke-Heist in West Flanders, Belgium. The data were collected since 2023, during spring and summer, in the ZNP’s provincial domain. This area is situated in a coastal dune zone between the ‘Zwin Plain’ and ‘Zwin dunes and polders’. All these Zwin subareas are situated within the European Natura 2000 network. This dataset is published as a standardised Darwin Core Archive and includes for each sampling event a parentEventID, grouping eventIDs per season, the sampling protocol, with sample size and unit, the country code, longitude and latitude with geodetic datum and coordinate uncertainty (in the event core), and for each occurrence, an occurrenceID, the scientific name, Dutch vernacular name, taxon rank, occurrence status (absent or present), the number of recorded individuals, and the identifiedBy term for the field observer’s name (in the occurrence extension). We have released this dataset to the public domain under a Creative Commons Attribution (CC-BY 4.0) implying that users of data make proper reference to this dataset. Samplingevent GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml Butterflies monitoring n/a Weather in 2023: notably cold spring, including persistent northeasterly winds during the second half of May and early June, that kept conditions often cool and windy, particularly in the afternoons. These unfavorable conditions meant fewer routes could be surveyed during that period. Later in the season, from late July to early August: much rain; no counts in that two-week period. When resuming transect counts from August 9th onwards, noticeably fewer butterflies were flying around than before, possibly indicating a substantial decline due to the heavy rain. Weather in 2024: mild, but very wet spring. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License. Creative Commons Attribution 4.0 International https://spdx.org/licenses/CC-BY-4.0.html CC-BY-4.0 The provincial domain of the Zwin Nature Park (ZNP) is located in the northernmost corner of West Flanders along the Belgian coastline fronting the North Sea. The adjacent Zwin Plain includes the border with the Netherlands. 3.344 3.353 51.361 51.358 2023-05-03 2024-09-23 This dataset covers 20 species and one species aggregate: all the butterflies, that have been seen at transect counts in the ZNP’s provincial domain since May 2023, are included. order Lepidoptera superfamily Papilionoidea Butterflies (Dagvlinders) family Nymphalidae Brush-footed butterflies (Schoenlappers, parelmoervlinders en zandoogjes) family Lycaenidae Gossamer-winged butterflies (Blauwtjes, kleine pages en vuurvlinders) family Hesperiidae Skippers (Dikkopjes) family Pieridae Whites (Witjes) annually Wouter Faveyts Zwin Natuur Park Scientific collaborator

West Flanders BE

wouter.faveyts@west-vlaanderen.be https://www.zwin.be/ All these observation data have consistently been counted by Wouter Faveyts, so far, in the field at the Zwin Nature Park. In Excel sheets per year, the data are collected, including summed numbers per taxon and per transect count. A brief description of the observation method is also provided. Based on those Excel sheets, Darwin Core data files are created through data wrangling in R, uploaded and documented with metadata in the IPT of the Belgian Biodiversity Platform by Stijn Cooleman. The dataset is published and registered with GBIF. This survey involves walking different routes within the Zwin Nature Park's provincial domain during the butterfly season, counting the number of butterflies seen. Not always adhering to strictly identical routes each time, these walks are usually along similar or the same transects, often re-surveying the exact same zones within the park. These counts are opportunistically conducted throughout spring and summer when weather conditions are good (sunny, warm and calm) and time permits. This flexible approach means the counting frequency is variable, ranging from largely weekly to, at times, several counts per day. * Weather in 2023: notably cold spring, including persistent northeasterly winds during the second half of May and early June, that kept conditions often cool and windy, particularly in the afternoons. These unfavorable conditions meant fewer routes could be surveyed during that period. Later in the season, from late July to early August: much rain; no counts in that two-week period. When resuming transect counts from August 9th onwards, noticeably fewer butterflies were flying around than before, possibly indicating a substantial decline due to the heavy rain. * Weather in 2024: mild, but very wet spring. A standardised observation protocol: counting all individuals of all butterfly species seen along the transects. Crucially, even when butterflies are absent, these 'zero' records are systematically logged in this comprehensive dataset. 2025-08-01T13:36:00.370+02:00 dataset Faveyts W, Cooleman S (2025). Butterfly transect counts at the Zwin Nature Park. Version 1.1. Belgian Biodiversity Platform. Samplingevent dataset. https://ipt.biodiversity.be/resource?r=zwin-park-butterflies-observations&v=1.1 c46d695c-bc44-439c-8645-cb04ef4cfe5d/v1.1.xml