An updated estimate of the wintering population of Sanderling Calidris alba (J.F. Gmelin, 1788) in Sicily for the years 2015-2022

The Sanderling Calidris alba (J.F. Gmelin, 1788) overwinters along the sandy coasts of Italy with an average of about 546 individuals for the years 2006-2010, showing a positive long- term increase. The species regularly overwinters in Sicily, for which the latest estimate reports 30–130 individuals in the years 2000–2004. Since no further updated estimates are available, new data were collected every winter on the field during the years 2015–2022, monitoring the most suitable stretches of beaches and collecting additional data from birdwatchers and photographers. A wintering regional population with an average of 100 individuals per year (65–136) was recorded, with an estimate of 145 individuals per year (110–180). The sandy coast of the Gulf of Gela hosts 54% of the recorded regional wintering population and about 10% of the whole Italian population and can therefore be considered a “site of national importance”. Other important areas are the Gulf of Catania, which hosts 24% of the regional population and 4.57% of the Italian population, and some sandy coasts of Ragusa’s province. This survey shows an increase of the regional wintering population in the last decades, highlighting Sicily’s role at national level for the wintering of the species. Conservation measures and sustainable management of Sicilian sandy coasts are strongly recommended to support the wintering of C. alba and other species of shorebirds.