Whooper Swan (Cygnus cygnus)

Whooper Swan

Subspecies

Monotypic species

Genus

Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae. There are six to seven species of swan in the genus Cygnus; in addition there is another species known as the Coscoroba Swan, although this species is no longer considered related to the true swans. All evidence suggests that the genus Cygnus evolved in Europe or western Eurasia during the Miocene, spreading all over the Northern Hemisphere until the Pliocene. When the southern species branched off is not known. The Mute Swan apparently is closest to the Southern Hemisphere Cygnus (del Hoyo et al., eds, Handbook of the Birds of the World); its habits of carrying the neck curved (not straight) and the wings fluffed (not flush) as well as its bill color and knob indicate that its closest living relative is actually the Black Swan. Given the biogeography and appearance of the subgenus Olor it seems likely that these are of a more recent origin, as evidence shows by their modern ranges (which were mostly uninhabitable during the last ice age) and great similarity between the taxa.

Physical charateristics

Size is similar to the Mute Swan, but there are noticeable differences. Whooper Swans have a yellow and black beak, a more rigid neck bearing in activiy as well as at rest, and, finally, their wings produce a musical sound when they fly.
Their feathers are entirely white and their webbed feet are black. Juveniles show a greyish brown plumage. After one year, they get their adult one.
The Whooper Swan can also be mistaken for the Bewick Swan whose he’s very close. There are two ways to differentiate them: the Whooper Swan is much bigger, with a longer neck and a more angulous head, and the beak’s yellow/black layout is different. While the Whooper’s Swan beak looks globally yellow with just a black tip, the Bewick’s Swan’s one is mainly black with a yellow base, sometimes half yellow, half black.
Unlike the Mute Swan, it never raises its wings above its back when it swims and its neck is straighter.

Listen to the sound of Whooper Swan

[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Whooper Swan.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.:	205	cm	wingspan max.:	235	cm
size min.:	140	cm	size max.:	160	cm
incubation min.:	31	days	incubation max.:	42	days
fledging min.:	78	days	fledging max.:	42	days
broods:	1		eggs min.:	3
			eggs max.:	5

Range

Eurasia : North

Habitat

Winters on low agricultural land, generally not far from coast.
Breeds in northern zones, on shallow fresh waters: pools, lakes and rivers in wooded country. Rarely in tundra.

Reproduction

Pairs unite for lifetime. Males are very active in nest building. Their nest is bulky and made essentially with stems and leaves. The bottom is covered with twigs, leaves and feathers. In April-May, the female lays 4 to 7 eggs and sits on for 5 to 6 weeks. Chicks are precocious and are carried on the female’s back under the male’s aggressive watch and protection. Taking flight occurs 87 to 90 days after hatching.

Feeding habits

Essentially vegetarian. It eats aquatic plants and uses all parts of it (stems, leaves, roots, shoots). It also graze in prairies, like geese. It may eat small invertebrates, but it’s a minor part of their diet.

Video Whooper Swan

httpv://www.youtube.com/watch?v=B69CDkrqu48

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Cygnus cygnus breeds mainly in Iceland, Fennoscandia and northern Russia, but
winters patchily across much of Europe, which constitutes >50% of its global wintering
range. Its European wintering population is relatively large (>65,000 individuals),
and was stable between 1970-1990. Although there were declines in a handful of
countries during 1990-2000, most European wintering populations-including key
ones in Denmark and Germany-were broadly stable or increased, and the species
underwent a large increase overall.
Whooper Swans nest mainly in Eurasian boreal regions. They split in three distinct groups. The most occidental one, with a stable population of about 16 000 individuals, nests in Iceland. The central one nests in Scandinavia and Occidental Russia. It is estimated at 59 000 individuals, regularly increasing. The most oriental group is located in Siberia. Its population, estimated at 17 000 individuals, is probably decreasing. These groups migrate south beginning autumn with the first cold days. The occidental group leaves Iceland for the British Isles, North Sea and Channel coasts, as far as the farthest point of Brittany. The oriental group sets up on Caspian and Black Sea shores. The Scandinavian group is the one that has the shortest migration. During winter, Whooper Swans, like Bewick Swans, spend a great deal of time grazing.

Migration

Migratory. Part of Icelandic population remains in winter. Migrates southwards to temperate areas, sporadically in more southern latitudes in cold winters; vagrant to USA and Pakistan.

Distribution map

Whooper Swan distribution range map

Planet of Birds