Cygnus olor - Mute Swan
Feather characters. Barbules are rather short (0.6-1.0 mm). Pigmentation is absent, but in dry slides nodes may look very dark. Triangular nodes are located on distal end, covering more than 60% of the total barbule length. On proximal end, nodal structures are visible but undeveloped and hardly swollen, and thus too small to qualify as nodes (15-20 per mm). An abrupt increase in size of nodes is seen distally along the barbules. In a very few cases triangular nodes may not be present. Villi are absent and internodes are occasionally kinked. Prongs are mostly located on distal end of barbules, on both sides of the pennulum. Sometimes they can be found along the entire length of the barbules, unequally distributed. Their length varies but the longest prongs may reach a length between half and the entire length of the adjacent internode.
Field characters. Size 145-160 cm. Weight: male 11800 g (9200-14300), female 9670 g (7600-10600) (Dunning, 1993). Differs from Tundra and Whooper Swan in orange-red bill with prominent black knob at base, and in carrying neck in a more graceful S-shaped curve. Legs black. Juveniles unevenly dingy brown above and whitish below, with greyish bills and legs.
Voice. Generally silent; hissing sound when nest or young are threatened. Wing-beats produce a loud, humming sound resembling "vaou-vaou-vaou".
Distribution. Originally a bird from steppe lakes, but introduced and semi-domesticated in many countries. Wholly migratory in some parts, moving short distances to form winter flocks in other parts, mainly sedentary in other regions. Map: see MapIt.
Habitat. Semi-domesticated birds frequent almost any kind of open, stagnant or slow-flowing waters with ample vegetation at depths which they can reach.
Food. Chiefly aquatic plants obtained at depths up to 1 m by immersing head and neck or by up-ending.