Jelentés A Gönyű-Szob közti Duna-szakasz (1791 – 1708 fkm) 2023. augusztus – 2024. április időszakának vízimadár felméréséről

Based on the results of the waterfowl counts (shown in Tables 2 and 3) completed during the 2023/2024 season in the section between Gönyű and Szob of the Danube river, we recorded the largest number of waterbirds (n=11 796) in January, while the smallest total number of birds occurred in August (n=247). The daily water level of the Danube River on the observation days shows Table 1. We observed the highest number of species (18 species) in January, while in March we saw only 7 species. During the 9-month study, we observed 25 species. Species that only appeared occasionally or in small numbers (˂100 per observation) included Cygnus olor (max. 46), Mergellus albellus (max. 3), Aythya ferina (max. 90), Mareca penelope (max. 26), Tachybaptus ruficollis (max. 2), Podiceps cristatus (max. 4), Egretta garzetta (max. 5), Ardea alba (max. 45), Ciconia ciconia (max. 1), Aquila heliaca (max. 5), Haliaeetus albicilla (max. 3), Vanellus vanellus (max. 95), Larus canus (max. 65) and Alcedo atthis (max. 1). Species that appeared in larger numbers and quantities (˃100 per observation) were as follows: Anser anser: 0–200, Anser albifrons: 0–130, Anas platyrhynchos: 33–8478, Phalacrocorax carbo: 27–789, Bucephala clangula: 0–1590, Chroicocephalus ridibundus: 14– 390, Aythya fuligula: 0–276 and Larus michahellis: 4–186. Figures 1 present the dynamics of common species. There are 3 known Great Cormorant nesting colonies in the studied section of the Danube; in 2024, 350–375 pairs nested there. There were 100–130 pairs of Grey Heron (Ardea cinerea) which, like the Great Cormorant, also nests in 3 colonies. There are also two known White-tailed Eagles (Haliaeetus albicilla) nests in the section of the Danube (Nagy-Erebe Island, Komárom Szt. Pál Island,); booth nests were inhabited in 2024, and breeding were as well. One pair of Imperial Eagle (Aquila heliaca) breeding at Neszmély on Radvány Island were still present during the nesting, but in this year on the south side of the island.