The whooper swan is similar in appearance to the Bewick's swan. It is larger, however, at a length of 140–165 cm (55–65 in) and a wingspan of 205–275 cm (81–108 in). Weight typically is in the range of 7.4–14 kg (16–31 lb), with an average of 9.8–11.4 kg (22–25 lb) for males and 8.2–9.2 kg (18–20 lb) for females. The verified record mass was 15.5 kg (34 lb) for a wintering male from Denmark. It is considered to be amongst the heaviest flying birds. Among standard measurements, the wing chord is 56.2–63.5 cm (22.1–25.0 in), the tarsus is 10.4–13 cm (4.1–5.1 in) and the bill is 9.2–11.6 cm (3.6–4.6 in). It has a more angular head shape and a more variable bill pattern that always shows more yellow than black (Bewick's swans have more black than yellow). Like their close relatives, whooper swans are vocal birds with a call similar to the trumpeter swan. Whooper swans have a deep honking call and, despite their size, are powerful fliers. Whooper swans can migrate hundreds or even thousands of miles to their wintering sites in southern Europe and eastern Asia. They breed in subarctic Eurasia, further south than Bewicks in the taiga zone. They are rare breeders in northern Scotland, particularly in Orkney, and no more than five pairs have bred there in recent years a handful of pairs have also bred in Ireland in recent years. This bird is an occasional vagrant to the Indian Subcontinent...Learn more about Whooper Swan