The timing of the spring migratory passage of Sylvia species over the southernmost point of Europe, Gavdos Island (Crete, Greece)

Abstract

Spring migration phenology is shifting towards earlier dates in response to climate change in many bird species. However, the patterns of change might not be the same for all species, populations, sex and age classes. The patterns of change could differ between species with different ecology and different lengths of migratory routes. We analyzed the timing of the spring migratory passage of seven species of the Sylvia genus on the island of Gavdos, Greece from mid-March to the end of May 2022 in order to determine specific species’ phenology following the crossing of the Mediterranean Sea. The first migrant Sylvia species that appeared on Gavdos during March were Sylvia rueppelli and Sylvia melanocephala, followed by Sylvia cantillans and Sylvia atricapilla. At the beginning of April, two more species were present on the island: Sylvia communis and Sylvia curruca, while during mid-April, Sylvia borin started migration across Gavdos. The first Sylvia warblers during spring passage were species wintering in Northern Africa and the Mediterranean (i.e. short-distance migrants) and in the Sahel zone, followed by long-distance migrants. The most numerous species during spring migration was Sylvia borin. The results of our study call for an intensification of data collection in the form of year-round tracking and long-term data sets at a large geographical scale to determine the impact of climate change on the timing of migration and its consequences on bird populations across Europe.