AVOCETTA - VOLUME 17 - N. 2
Differences in diet of Common (Apus apus) and Pallid (A. pallidus) SwiftsCucco M., BRYANT D. M. AND MALACARNE G.
Abstract:The diets of Common (Apus apus) and Pallid Swift (A. pallidus) were compared by faecal and food bolus analysis in a mixed colony in NW Italy. The size of insect-remains increased with age of nestlings in both species. Size (mm) and mean dry mass of insect prey items was greater in the Common Swift. There were also differences in the taxonomic composition of prey: the Common Swift took more aphids in lune, and Heteroptera and Coleoptera in luly, while the Pallid Swift caught more Acalyptera in lune, and Hymenoptera in luly . Food balls and faecal analysis agreed in their description of swift diets. A comparison with aerial arthropod abundance, sampled by suction trap, suggested a positive selection of Hymenoptera and Coleoptera, while Diptera were more frequent in suction trap samples than in the swifts' diets.