The Dalles, Oregon, USA
Placed by some in genus Olor with C. buccinator and C. cygnus. Subspecies bewickii has been regarded as a full species, but morphologically it is distinguished only by the yellow on the bill (which may, however, be variable) and possibly slightly smaller size. Population of NE Asia has been assigned a separate subspecies jankowskyi, though doubtfully valid. Two subspecies recognized.
- C. c. bewickii (Yarrell, 1830) – Bewick’s Swan – Kola Peninsula E throughout Arctic N Siberia; winters in W Europe, S of Caspian Sea and E China, Korea and Japan.
- C. c. columbianus (Ord, 1815) – Tundra Swan – tundra of Arctic North America, also extreme NE Siberia; winters in W and coastal E USA and N Mexico.
120–150 cm, male 3800–10,500 g, female 4100–9000 g (nominate); 115–140 cm, male 4536–8391 g, female 4300–7825 g (bewickii);...Nominate is very vocal throughout the year, especially on water and in flight, with calls serving...Breeds on shallow pools, lakes and rivers of moist Arctic tundra. On migration, in North Dakota
Mainly leaves, roots, rhizomes and stems of aquatic plants (Potamogeton, Zostera, Glyceria) and grasses,
foto Mihai Baciu