Andrzej Dombrowski, Sławomir Chmielewski, Dariusz Bukaciński, Krzysztof Antczak, Marek Murawski, Piotr Pagórski
Ornis Polonica 2021, 62: 89–100
https://doi.org/10.12657/ornis.2021.2.1
Abstract: In 2007–2017 18 breeding species were counted in the river beds of the central Vistula and lower sections of the Narew, Bug, Pilica, Wkra and Liwiec rivers. The Sand Martin Riparia riparia (27,662–28,161 burrows) and the Black-headed Gull Chroicocephalus ridibundus (13,026–14,480 pairs) were the most abundant species. Other surveyed species were the Common Tern Sterna hirundo (1,636–1,798 pairs), Little Tern Sternula albifrons (460–531 p.), Mew Gull Larus canus (680–787 p.), Common Sandpiper Actitis hypoleucos (404–455 p.), Little Ringed Plover Charadrius dubius (242–304 p.), Goosander Mergus merganser (186–215 p.), Common Kingfisher Alcedo atthis (168–193 p.), Ringed Plover Ch. hiaticula (145–168 p.), Herring Gull L. argentatus sensu lato (78–111 p.), Mediterranean Gull Ichthyaetus melanocephalus (16–19 p.), Bluethroat Luscinia svecica (12–19 p.), Eurasian Oystercatcher Haematopus ostralegus (9–12 p.), Common Shelduck Tadorna tadorna (8–10 p.) and Lesser Black-backed Gull L. fuscus (5 p.). After two decades (1984–1993 vs 2017–2017), the abundance of ten species decreased, while the number of six increased. The largest increase concerned Goosander, Eurasian Oystercatcher and Caspian Gull L. cachinnans, as well as large gulls, while the largest decrease was observed in the Mew Gull, Bluethroat and Ringed Plover. The Stone Curlew Burhinus oedicnemus stopped nesting, and two species, the Lesser Black-backed Gull and Common Shelduck, started to breed. Despite a decreasing trend for many species, the central Vistula basin is still the most important national breeding ground for four species: Mew Gull, Ringed Plover, Eurasian Oystercatcher and Little Tern.
Keywords: breeding birds, changes in the number of birds, the middle Vistula basin
