Tundra swans are monogamous, forming pairs in autumn. In spring, they leave their wintering areas and return to the arctic and subarctic regions of North America and northeastern Siberia. From May to June, they nest on islets, peninsulas and elev ated hummocks of the open tundra. A pen will lay 3 to 4 eggs that she will incubate for 35 to 40 days, although the cob may sit on the nest while she feeds, mostly at night. The young are ready to fly after two months.
Tundra swans winter across the United States.
Tundra swans from as far away as the Bering Sea and the Arctic Ocean, fly east over Canada and then southeast to the Bay. The wing beat is slow and steady. They arrive during October and November and usually flock by themselves away from other birds. Until recently, the Chesapeake Bay was the most important wintering area on the Atlantic Coast for tundra swans. During the late 1960s, more than 40,000 tundra swans wintered on Bay.