The diet of insectivorous ducklings and the acidification of small Ontario lakes

摘要: We examined the diet of insectivorous ducklings four species waterfowl, Common Goldeneye (Bucephala clangula), Ring-necked Duck (Aythya collaris), Hooded Merganser (Lophodytes cucullatus), and American Black (Anas rubripes), collected from small lakes covering a range acidity in northeastern Ontario. The numbers Odonata larvae, aquatic Hemiptera, Coleoptera, Trichoptera larvae eaten by were estimated combined esophageal gizzard contents analysed with respect to differences lake fish presence. Ducklings all species, especially Merganser, ate significantly more nektonic prey, Notonectidae (Hemiptera) Dytiscidae (Coleoptera), without than fish. other Anisoptera on acidic lakes. teneral There was tendency for b...