Abstract
Migratory and wintering behaviour of the great white egret Ardea alba in Central and Eastern Europe remains poorly known. Here, we investigated for the first time year-round movements, habitat use, selectivity, and site fidelity during the non-breeding period of this species from the European population, based on global positioning system (GPS) tracking between 2015 and 2023. We investigated differences between spring and autumn migrations and habitats used by great white egrets during post-breeding dispersion, migrations, and wintering within their home ranges. All 15 instrumented birds showed migratory behaviour after breeding, moving between wintering sites in Western Europe and breeding grounds in Central and Eastern Europe. The duration of autumn migration was longer than that of spring migration and included more frequent and longer stopovers. We found high inter-individual variability in duration, home range size of every considered phase and the number of stopovers. We showed that all the studied individuals started their autumn migration between 10 July and 12 November and arrived at their wintering grounds between 18 August and 18 January. The spring migration started between 17 February and 24 April and finished between 8 March and 24 May. We showed that aquatic and farmland habitats were used most frequently by great white egrets, indicating their significance for foraging by this species. These habitats were mostly selected positively during the non-breeding period, while urban habitats were selected negatively. Our research provides valuable insight into the movement and habitat ecology of the great white egret during its range expansion.