Włodzimierz Meissner, Andrzej Kośmicki, Piotr Rydzkowski
Ornis Polonica 2024, 65: 324–336
https://doi.org/10.12657/ornis.2024.4.3
Abstract: In this paper, we present the characteristics of the grouping of waterbirds residing in the Port of Gdynia area during the non-breeding season. The port is the largest port for the transportation of agricultural products in the Baltic Sea, and the volume of their annual transshipment in the years 2019–2022 ranged from 3.2 to 6.7 million tons. Overwintering waterbirds were counted once a month from September to April during the 2019/2020–2023/2024 seasons, and 27 species of birds associated with the water environment were recorded, of which the Mallard Anas platyrhynchos, Herring Gull Larus argentatus s.l., Common Gull L. canus and Black-headed Gull Chroicocephalus ridibundus occurred in greater numbers. Together they accounted for 82% to 95% of all waterbirds present in the Port of Gdynia from September to March and 68% in April. A maximum of 11,591 Common Gulls, 10,914 Mallards, 9,372 Herring Gulls s.l. and 3,034 Black-headed Gulls were observed here during a single visit. Of the analyzed species, only the mean abundance of Mallard in consecutive months was correlated between the Port of Gdynia and the western part of the Gulf of Gdańsk. The largest number of waterbirds congregated in port basin B III, where grain and its products were handled. The maximum number of birds found here was 18,918 and 18,057, in January and February 2024, respectively. With very high handling, even small losses in conveyed mass result in an abundant food source for birds, which is the reason for very high concentrations of the most numerous four species in the area. As a result, the Port of Gdynia is now one of the dozen or so most important wintering sites for waterbirds in Poland.
Keywords: anthropogenic environment, Black-headed Gull, Gulf of Gdańsk, Herring Gull, Mallard
