Funding for this research was provided by:
Bundesamt für Naturschutz (FKZ 3519861400, FKZ 3515822100)
Christian-Albrechts-Universität zu Kiel
German Federal Ministry of Research and Education (FKZ 03F672B)
Received: 18 November 2020
Accepted: 4 March 2021
First Online: 17 March 2021
: Permission to attach GPS tags was issued by the Ministerium für Energiewende, Landwirschaft, Umwelt, Natur und Digitalisierung of the federal state of Schleswig-Holstein (file numbers V 312-7224.121-37(42-3/13) and V 241-35852/2017(88-7/17)) as well as by the Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit of the federal state of Lower Saxony (file number 33-19-42502-04-17/2699). Catching and treatment of birds complied with current EU and German laws. All authors consent to participate in this study.
: Not applicable.
: The authors declare that they have no competing interests.