The Common Rock Thrush (Monticola saxatilis) in the Carpathian Basin

The Common Rock Thrush (Monticola saxatilis) is a species with an extremly large distribution range. Its European population is the strongest in the Mediterranean, but it also breeds in Central Europe. It still nests in small numbers in the Carpathian Basin, but has become extinct as a breeder in Hungary, where it was never a common species. In the present study, we summarised the occurrences of the species in the Carpathian Basin published in the literature. In the late 19^th and early 20th centuries, a large amount of observational data on the spring migration of the species was collected, which allowed us to describe the migration phenology of that time. The Common Rock Thrush bred in small numbers in mountainous areas of Hungary, in natural habitats and in mines, vineyards and orchards. The collapse of the population occurred in the 1970s, but thereafter a few pairs bred in Hungary until the 2010s. Very few published records were found in Slovakia and Romania, which does not give a true picture of its former distribution there. However, its population has also declined drastically in Romania and it has become extinct as nesting species in Slovakia. The exact cause of the decline cannot be determined and several explanations have been proposed in recent decades. It is likely that the Carpathian Basin population, which is considered to be an edge-population, has been more exposed to negative changes, such as climate change, chemical inputs or changes in wintering grounds. A century earlier, the median date of the first spring returns was mid-April, but sometimes it was observed as early as late March. Nowadays, vagrant individuals have been observed again several times in Hungary, which gives us some hope for the future.