Anas platyrhynchos 1 Catostomus 1 Catostomus catostomus 1 Catostomus commersoni 1 Coregonus clupeaformis 1 DNA 1 DNA metabarcoding 1 Diet 1 Faecal samples 1 Feeding 1 Fish 1 Great Lakes 1 Great Lakes [North America] 1 Great lakes 1 Gut content 1 Gut contents 1 Hematophagy 1 Lake Huron 1 Lake hurons Lake trout 1 Lakes 1 Lamprey 1 Matthiola 1 Nutrition 1 Petromyzon marinus 1 Petromyzontidae 1 Pisces 1 Salvelinus namaycush 1 Sea lampreys 1 blood 1