Włodzimierz Meissner, Łukasz Wardecki, Jacek Antczak, Jacek Betleja, Dawid Cząstkiewicz, Paweł Czechowski, Maciej Filipiuk, Paweł Grochowski, Grzegorz Grygoruk, Robert Hybsz, Adam Kaliński, Marcin Łukaszewicz, Dominik Marchowski, Patryk Rowiński, Piotr Rydzkowski, Włodzimierz Szczepaniak, Kazimierz Walasz, Tomasz Chodkiewicz
Ornis Polonica 2024, 65: 93–113
https://doi.org/10.12657/ornis.2024.2.2
Abstract: In January 2023, waterbirds surveys were conducted in 253 localities. The study included the results of counts carried out on water bodies located within the boundaries of urban development, where their occurrence was favoured by human feeding of birds, as well as by the discharge of hot water or sewage. A total of 104 574 wintering birds of 42 species were recorded, of which the most numerous were Mallard Anas platyrhynchos (68 997 inds), Black-headed Gull Chroicocephalus ridibundus (16 726 inds), Coot Fulica atra (6 482 inds) and Common Gull Larus canus (3 176 inds). Mallards wintered most abundantly in Warsaw and Wrocław, where their numbers were 4 971 and 2 276 inds respectively. The highest numbers of Black-headed and Common Gulls were recorded in Gdańsk (2 858 inds and 939 respectively). Larger groups of Black-headed Gulls were observed in cities along the Vistula and Odra rivers or on the Baltic coast, while Common Gulls were found mainly in towns in the northern part of the country and were also more numerous in Bielsko-Biała (354 individuals) and Warsaw (193 inds). Wintering Coots were not found in many towns located in the central and eastern part of the country, and the highest number of birds of that species (3 743 inds) was recorded in Kamień Pomorski. The highest abundance of Mute Swans Cygnus olor was recorded in Bydgoszcz, where 143 inds were present, but 78% of the towns where the species was found had fewer than 10 individuals. The results obtained for Mallard, Mute Swan and Coot were compared with data collected in the years 2007–2009, when a similar survey was conducted for the first time. In case of Mallard and Mute Swan, most birds congregated in towns during winters with the lowest temperatures. A correlation between temperature in January and bird abundance was not recorded for the Coot.
Keywords: citizen science, population abundance, urban areas, water bodies, winter
