A Magyarországon fészkelő sirályfélék (Laridae) állományviszonyai és vonulása

The aim of my research topic is to determine the nesting populations of the gull species breeding in Hungary: the Black-headed Gull (Chroicocephalus ridibundus), the Mediterranean Gull (Ichthyaetus melanocephalus), the Mew Gull (Larus canus), the Yellowlegged Gull (Larus michahellis) and the Caspian Gull (Larus cachinnans) as accurately as possible, and to study the migration of these species based on bird ringing data, especially to process the results of coloured rings. The basis of my motivation is that I have been engaged in bird ringing and migration research for three decades. My interest turned to colonial nesting waterfowl, especially gulls. Over the years, with many helpers, I ringed more than ten thousand gulls, primarily Blackheaded Gull chicks. I also joined in the ringing of Caspian Gulls and Common Gulls, which occur as relatively new breeding species in Hungary. In the Hungarian ornithological literature, it is possible to detect the changes of population conditions in the case of certain species almost from a historical perspective. Data series are available primarily on rare birds of prey, and large or otherwise significant bird species, such as the Great Egret (Ardea alba), the Great Bustard (Otis tarda), the White Stork (Ciconia ciconia), the Rook (Corvus frugilegus), the Imperial Eagle (Aquila heliaca) or the Saker Falcon (Falco cherrug). The conditions of the Mediterranean Gull population were fairly documented between 1950 and 1995, but there is no standardized national database available for the following decades. In Hungary, it is nearly impossible to find exact data on nesting pairs and population change of moderately common or moderately rare birds. In order to address this problem, BirdLife Hungary (MME) established the Hungarian Monitoring of Common Breeding Birds (MMM) program (BirdLife Hungary Monitoring Centre 1999–2011). Unfortunately, this did not work for the Black-headed Gull, as the trend of its nesting population between 1999 and 2021 was uncertain.