Jelentés A Gönyű-Szob közti Duna-szakasz (1791 – 1708 fkm) 2024. augusztus – 2025. április időszakának vízimadár felméréséről

Based on the results of the waterfowl counts (shown in Tables 2 and 3) completed during the 2024/2025 season in the section between Gönyű and Szob of the Danube river, we recorded the largest number of Waterbird (n=7770) in January, while the smallest total number of birds occurred in April (n=1020). The daily water level of the Danube River on the observation days shows Table 1. We observed the highest number of species (20 species) in November, while in August, December and April we saw only 12–12 species. During the 8-month study, we observed 28 species. Species that only appeared occasionally or in small numbers (˂100 per observation) included Cygnus olor (max. 40), Tadorna tadorna (max. 4), Mergellus albellus (max. 5), Spatula querquedula (max. 2), Aythya ferina (max. 11), Mareca penelope (max. 27), Anas crecca (max. 7), Anas acuta (max. 2), Gavia arctica (max. 1), Podiceps cristatus (max. 7), a Podiceps nigricollis (max. 1 pd), Ardea cinerea (max. 82), Ardea alba (max. 53), a Nycticorax nycticorax (max. 8 pd), Aquila heliaca (max. 3), Haliaeetus albicilla (max. 4), Tringa ochropus (max. 1) and Sterna hirundo (max. 11). Species that appeared in larger numbers and quantities (˃100 per observation) were as follows: Anser anser: 0–311, Anas platyrhynchos: 119–4111, Mergus merganser: 0–177, Bucephala clangula: 0–1368, Aythya fuligula: 0–507, Phalacrocorax carbo: 50–949, Chroicocephalus ridibundus: 0–734, Larus canus: 3–148 and Larus michahellis: 23–761. Figures 1 present the dynamics of common species. There are three known Great Cormorant nesting colonies in the studied section of the Danube; in 2025, 340–375 pairs nested there. There were 105–130 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 2025, 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.