A study of the autumn food habits of ducks and coots at Swan lake, British Columbia, based on the examination of 136 stomachs and on co-related field work, indicates the following conclusions: pond ducks had eaten 78% plant material, 12% Chara, and 10% animal organisms; the food of diving ducks was 65% plant material, 31% Chara, and 15% animal matter; while that of coots was 97% Chara and 3% plant material. Chara is the dominant growth in the lake. It is produced in unlimited quantities so that the food requirements of coots do not seriously compete with those of ducks.