Study area and species
The study was carried out on colonial and gregarious species of waterbirds in northern Poland (Europe). Most of the observations were made in the lower course and estuary of a large lowland river – the Lower Oder Valley (site-centre location in decimal degrees: Longitude - 14.413200, Latitude - 53.085000). The observations were made in areas known for their importance for waterbirds, during the breeding season, migration, and the wintering period. (Ławicki et al. 2010, Marchowski et al. 2018).
The study covered a total of 33 species of waterbirds, including 15 breeding and 28 non-breeding species. The responses of 10 species to the drone in both the breeding and non-breeding periods were compared.
Table 1. List of species surveyed using a drone.