Cygnus cygnus Linnaeus, 1758 (juveniles)
Common names: Whooper Swan [En], Cygne chanteur [Fr], Wilde Zwaan [Nl], Singschwan [De], Cigno selvatico [It], Cisne Cantor [Es], Αγριόκυκvoς [Gr], Ötücü kuğu [Tu]
IUC Status: LC (Préoccupation mineure)
Kerkini Lake, SERRES ● Greece
Description: The whooper swan is similar in appearance to the Bewick's swan Bewick (Cygnus columbianus bewickii). It is larger, however, at a length of 140–165 cm and a wingspan of 205–275 cm.
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.
Biology: Whooper swans have a deep honking call and, despite their size, are powerful fliers.
Whooper swans breed once a year, their breeding season begins in late April and early May.
Whooper swans pair for life, and their cygnets stay with them all winter; they are sometimes joined by offspring from previous years. Nests are often situated on a large mound near a body of fresh water with riparian vegetation nearby for protection. Both the male and female help build the nest, and the male will stand guard over the nest while the female incubates. Their eggs are large and elliptical with an off-white coloration. The female will usually lay 4–7 eggs (exceptionally 12). The cygnets hatch after about 36 days and have a grey or brown plumage. The cygnets leave the nest 2 to 3 days after hatching. After three months, chicks begin to fledge and are able to fly at 78 to 96 days. Fledglings become independent after a year and become sexually mature after about 4 years, which is an uncommonly long time.
Habitat: Whooper swans breed and set up nests along the banks of freshwater lakes, pools, shallow rivers, marshes, bogs, and swamps. They prefer habitats with emergent vegetation, which may provide additional protection for nests and newborn cygnets. Non-breeding pairs of swans can be found near sheltered estuaries, lagoons, and shallow bays. Migrating whooper swans fly at altitudes of 500 to 1,700 m when crossing oceans, but often prefer flying at lower levels to allow for frequent breaks between flights. Near the British Isles, migrating whooper swans have been recorded reaching heights above 8,000 m.
Distribution: Whooper swans have an extensive geographic range and can be found within the boreal zone in Eurasia and many nearby islands. They breed in subarctic Eurasia, further south than Bewicks in the taiga zone. They are rare breeders in northern Scotland. Icelandic breeders overwinter in the United Kingdom and Ireland. Whooper swans can migrate hundreds or even thousands of miles to their wintering sites in southern Europe and eastern Asia.
Wikipedia, Whooper swan
Animal Diversity Web