O_ASSEN - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) breeding in Assen (the Netherlands) is a bird tracking dataset published by the Vogelwerkgroep Assen, Netherlands Institute of Ecology (NIOO-KNAW), Sovon, Radboud University, the University of Amsterdam and the Research Institute for Nature and Forest (INBO). It contains animal tracking data collected for the study O_ASSEN using trackers developed by the University of Amsterdam Bird Tracking System (UvA-BiTS, http://www.uva-bits.nl). The study was operational from 2018 to 2019. In total 6 individuals of Eurasian oystercatchers (Haematopus ostralegus) have been tagged as a breeding bird in the city of Assen (the Netherlands), mainly to study space use of oystercatchers breeding in urban areas. Data are uploaded from the UvA-BiTS database to Movebank and from there archived on Zenodo (see https://github.com/inbo/bird-tracking). No new data are expected. See van der Kolk et al. (2022, https://doi.org/10.3897/zookeys.1123.90623) for a more detailed description of this dataset. Data in this package are exported from Movebank study O_ASSEN - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) breeding in Assen (the Netherlands) (Movebank Study ID 1605797471), which can be viewed at https://www.movebank.org/cms/webapp?gwt_fragment=page=studies,path=study1605797471. Fields in the data follow the Movebank Attribute Dictionary (http://vocab.nerc.ac.uk/collection/MVB) and are described in datapackage.json. Files Files are structured as a Frictionless Data Package. You can access all data in R via https://zenodo.org/record/5653311/files/datapackage.json using frictionless. datapackage.json: technical description of the data files. O_ASSEN-reference-data.csv: reference data about the animals, tags and deployments. O_ASSEN-gps-yyyy.csv.gz: GPS data recorded by the tags, grouped by year. O_ASSEN-acceleration-yyyy.csv.gz: acceleration data recorded by the tags, grouped by year. ; These data were collected by Bert Dijkstra and Rinus Dillerop ...