NECTAR EXPLOITATION BY SONGBIRDS AT MEDITERRANEAN STOPOVER SITES

Nectar exploitation by songbirds at Mediterranean stopover sites. The nectar use by songbirds in Europe is reported by many authors but several of them refer to local or occasional events on both introduced and native plants. A study carried out on Ventotene Island (Italy) shows that nectar could be an important food resource for migrants which land at stopover sites. In this study we investigated the distribution of nectar feeding behaviour at Mediterranean stopover sites in spring, checking 10 species for the presence of pollen on plumage during ringing activities carried out at 14 stopover sites placed in Spain, Italy and Greece. Moreover we investigated the possible relationship between nectar consumption by migrants and vegetation at three stopover sites, through the time budget analysis of 8 species during no-flight activities. Sylvia and Phylloscopus species were often found to use nectar, the former more frequently than the latter. However, nectar exploitation results usual only at 2 Mediterranean sites out of 14, Ventotene and Antikythira (Greece), while it seems to be common at African stopover sites. The analysis of time budget and the pattern of nectar feeding distribution at stopover sites suggests that in the Mediterranean region nectar consumption is most likely related to the youngest phases of vegetation, these possibly being richer in flowering plants potentially usable by songbirds.