The origin of Caspian Gulls Larus cachinnans wintering in Croatia

The Caspian Gull is a breeding species of eastern Europe and central Asia, whose breeding range has over the last 100 years been expanding to western parts of Europe. It is regularly seen on migration and wintering in Croatia. Since the historical literature data for Larus cachinnans in Croatia mainly refer to the Yellow-legged Gull, the aim of this research was to determine the origin of Caspian Gulls wintering in Croatia. Recoveries from the Prudinec rubbish dump in Zagreb and the ones ob-tained from the ringing archive of the Institute of Ornithology, Croatian Academy of Sciences and Arts have been analysed. Ringed individuals seen in Croatia belong to the populations from central and eastern Europe, and the first ringed individual from the Black Sea population has been recorded. Compared to the available literature data, four new countries of origin of Caspian Gulls seen in Croatia have been recorded: Lithuania, the Czech Republic, Hungary, and Romania. The longest distance from the place of recovery (Croatia) to the place where the individual has been ringed (Ukraine) is 1507 kilometres. Ringed individuals were recorded in Croatia from October to March.