Northern Prairie Wildlife Research Center
The 85% decrease of breeding ducks since 1961 at two ponds 1 ha in area near the reservoir of Egglfing by the River Inn was presumably caused solely by disturbance from an increasing number of anglers during the breeding season. Numbers of mallard (Anas platyrhynchos), green-winged teal (Anas crecca), northern shoveler (Anas clypeata), common pochard (Aythya ferina), and tufted duck (Aythya fuligula) decreased from 26 pairs with 134 ducklings in 1961 to 4 pairs with 19 ducklings in 1969. Surface-feeding ducks have vanished completely from the area. Food plants have not changed in this period. A limitation on fishing is urgently needed to conserve breeding duck numbers.