Winter habitat - In winter, tundra swans use extensive shallow fresh and brackish water. They are less frequently found on salt water. Tall emergent vegetation provides shelter and cover for tundra swans. Tundra swans eat the stems, seeds, and bulbous roots of aquatic plants, and the seeds and young shoots of cultivated grains. Tundra swans also feed on waste corn in both dry and flooded fields and upon harvested potatoes.
Little information is available in the literature regarding predation on tundra swans.
In a few states, experimental hunting of tundra swans is allowed. Winter surveys of tundra swans during the 1950's in the United States revealed an average population of 78,000. This figure increased to 98,000 during the 1960's and to 133,000 during 1970-74. The lowest population recorded from 1949 to 1974 was in 1950 at 49,000, and the highest was 157,000 in January 1971.