The Ruddy shelduck (Tadorna ferruginea) is a distinctive waterfowl that has a loud honking call. The ruddy shelduck mostly inhabits inland water-bodies and forms a lonf lasting pair bond. In central and eastern Asia, populations of this species are steady or rising, but in Europe, they are generally in decline.
The male Ruddy shelduck has orange-brown body plumage and a paler, orange-brown head and neck, separated from the body by a narrow black collar. The rump, flight feathers, tail-coverts, and tail feathers are black and there are iridescent green speculum feathers on the inner surfaces of the wings. Both upper and lower wing coverts are white, this feature being particularly noticeable in flight but hardly visible when the bird is at rest. The bill is black and the legs are dark grey. The female is similar but has a rather pale, whitish head and neck and lacks the black collar, and in both sexes, the coloring is variable and fades as the feathers age. The birds molt at the end of the breeding season and the male loses the black collar, but a further partial molt between December and April restores it. Juveniles are similar to the female but are a darker shade of brown.
Ruddy shelducks breed from southeast Europe across the Palearctic to Lake Baikal, Mongolia, and western China. There are also very small resident populations of this species in Northwest Africa and Ethiopia. Most populations are migratory, wintering in the Indian subcontinent and breeding in southeastern Europe and central Asia, though there are small resident populations in North Africa. Ruddy shelducks are usually found in open locations on inland bodies of water such as lakes, reservoirs, and rivers. They rarely occur in forested areas but do occur in brackish water and saline lagoons.
They typically breed in large wetlands and rivers with mud flats and shingle banks, and they are found in large numbers on lakes and reservoirs. They breed in high-altitude lakes and swamps in Jammu and Kashmir. Outside the breeding season, they prefer lowland streams, sluggish rivers, ponds, flooded grassland, marshes, and brackish lagoons.
In Europe, populations of Ruddy shelducks are generally declining as wetlands are drained and the birds are hunted. However, they are less vulnerable than some other waterfowl because they can adapt to new habitats such as reservoirs.
Ruddy shelducks are social birds. They are usually found in pairs or small groups and rarely form large flocks. However, molting and wintering gatherings on chosen lakes or slow rivers can be very large. Ruddy shelducks are active during the night. On land, they graze on the foliage, but when in the water they do not dive; they dabble in the shallows, and at greater depths, they up-end. Ruddy shelducks are very noisy when in flocks. Their call is a series of loud, nasal honking notes. The calls are made both on the ground and in the air, and the sounds are variable according to the circumstances in which they are uttered.
Ruddy shelducks are monogamous a form strong pair bonds that are thought to last for life. The birds arrive at their main breeding grounds in central Asia in March and April. When nesting Ruddy shelducks are very aggressive towards their own kind and towards other species. The female in particular approaches intruders with head lowered and neck outstretched, uttering anger calls. If the intruder stands its ground, the female returns to the male and runs around him, inciting him to attack. He may or may not do so. Courtship ritual includes neck stretching, head dipping, and tail raising. The nesting site is often far away from water in a hole in a tree or ruined building, a crevice in a cliff, among sand dunes, or in an animal burrow. The nest is constructed by the female using feathers and down and some grasses. The female lays 6-12 eggs between late April and early June and incubates them alone while the male stands in attendance nearby. The eggs hatch after about 28 days and both parents care for the young, which fledge in a further 55 days. After breeding the adults moult, losing the power of flight for about a month while they do so. Before molting they move to large water bodies where they can more easily avoid predation while they are flightless. The family may stay together as a group for some time; the autumn migration starts around September and the young may mature in their second year. North African birds usually breed about 5 weeks earlier.
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