Shelduck

Tadorna tadorna

58-67cm

Appearance

This a large, goose-sized duck, slightly bigger than the Mallard. It has distinct markings, particularly the colourful elements of its plumage which become bolder in good light. It's a white duck with a bottle-green head and neck – the head can look dark when the bird is in shadow. The breast-band is chestnut coloured and there's a smudge of orange underneath the tail. It has a blood-red bill, pink legs, black shoulders and a black belly stripe which is particularly visible when in flight. While in the air, the wings flash contrasting white and black flight feathers. Males are larger and brighter than females and they have an obvious knob at the base of their bills during spring. The juvenile is grey-brown, its markings yet to pronounce themselves.

Habitat

Lives primarily near the coast on estuaries with sandbars and mudflats, but small numbers have recently adopted some inland freshwater sites.

Character

This bird up-ends to reach food below the water's surface. It swims high in the water and wades, sifting food out of the mud with its bill. Its wingbeats are long and heavy.

Food

This bird consumes invertebrates such as shellfish, crab, shrimps, worms, sandhoppers and larvae of flies and other insects. It does eat some plant material as well. A tiny snail called Hydrobia is an important food source on estuaries.

Breeding

Prefers to nest in holes, this bird has been known to use old rabbit burrows, dense vegetation, or gaps in buildings. The female lays 8-10 eggs in April or May and incubates them for about 30 days. A few hours after hatching, young can feed themselves; they're led by the female to an area with plenty to eat and here they often mix with other young Shelducks. Non-breeding adults ('aunties') often tend the groups of young while parents migrate to their moulting areas. Young fly in approximately 45 days.

Population

Most birds will migrate to traditional moulting grounds after breeding. Thousands gather in the Heligoland Bight off the German coast and other moulting areas have been discovered on some British estuaries and sites, such as Bridgwater Bay in Somerset. Other birds travel to Waddenzee in the Netherlands in order to moult. Birds from western Europe boost the British population in winter. In summer there are up to 15 000 pairs in the UK and 1000 in Ireland, and after breeding there may be over 80 000 Shelducks in Britain and Ireland.

Observation Tips

Easy to see on most estuaries, except in July and August.

Voice

The male is mostly silent, although when courting they utter a sweet, whistling call. The female has lower vocals, a 'ga, ga, ga' cackle.