Spring migration at the southmost stop-over site in Europe, the Gavdos Island (Crete, Greece)

Abstract

The island of Gavdos, located south of Crete and only 250km north of African coast plays an important role for migratory birds in spring being the first land where birds can re-fuel and rest after the long open-sea crossing. Bird ringing surveys conducted in spring of 2002-2004 revealed that the island funnels migrants from a very wide range of Eurasia, probably reaching east to Siberia. The survey was initiated again after 18 years in early June 2021, and carried out in full intensity in spring 2022, with 500m of mist nets used for 75 days from mid-March to end of May. The nets were opened from 06:00-19:00 at two ringing sites on the island, covering all the major habitats for birds on passage, excluding the shore. A total of 3103 individuals of 63 species were ringed, with 49 individuals of 19 species retrapped, and a single foreign recovery (Germany) obtained. The most trapped species was Hirundo rustica (15.5%), followed by Sylvia borin (14.44%) and Motacilla flava (8.5%). A notable number of Sylvia communis (7%), Muscicapa striata (6.9%), Anthus trivialis (4%) and Ficedula hypoleuca (4.16%) were also trapped. Noteworthy were also the records of Merops persicus (N=2), and Sylvia ruepelli (N=7). Sylvia species were the most common genus trapped (28%). These results call for an intensification of mist-netting of birds at Gavdos, as the study of migratory patterns on this remote island can provide a unique window into the bird migration across the central Aegean migratory corridor.