The ruddy shelduck ( Tadorna ferruginea), known in India as the Brahminy duck, is a bird species in the family Anatidae. It is a distinctive waterfowl, in length with a wingspan of . It has orange-brown body plumage with a paler head, while the tail and the flight feathers in the wings are black, contrasting with the white wing-coverts. It is a Bird migration, wintering in the Indian subcontinent and breeding in southeastern Europe and central Asia, though there are small resident populations in North Africa. It has a loud honking call.
The ruddy shelduck mostly inhabits inland water-bodies such as lakes, reservoirs and rivers. The male and female form a lasting pair bond and the nest may be well away from water, in a crevice or hole in a cliff, tree or similar site. A clutch of about eight eggs is laid and is Egg incubation solely by the female for about four weeks. The young are cared for by both parents and fledge about eight weeks after hatching.
In central and eastern Asia, populations are steady or rising, but in Europe they are generally in decline. Altogether, the birds have a wide range and large total population, and the International Union for Conservation of Nature has assessed their conservation status as being of least concern.
The genus name Tadorna comes from the French tadorne, the common shelduck, and may originally derive from a Celtic word meaning "pied waterfowl". The English language name "sheld duck" dates from around 1700 and means the same. The specific name ferruginea is Latin for "rusty" and refers to the colour of the plumage.
The call is a series of loud, nasal honking notes, it being possible to discern the difference between those produced by the male and the female. 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.
Although becoming quite rare in Southeastern Europe and southern Spain, the ruddy shelduck is still common across much of its Asian range. It may be this population which gives rise to vagrants as far west as Iceland, Great Britain and Ireland. However, since the European population is declining, it is likely that most occurrences in Western Europe in recent decades are escapes or Feral animal birds. Although this bird is observed in the wild from time to time in eastern North America, no evidence has been found that this is a genuine case of vagrancy. Feral ruddy shelduck have bred successfully in several European countries. In Switzerland the ruddy shelduck is considered an invasive species that threatens to displace native birds. Despite actions taken to reduce numbers, the population of ruddy shelduck in Switzerland increased from 211 to 1250 individuals in the period from 2006 to 2016.
A stable population exists in Moscow, settling the city parks' ponds alongside the endemic . It is theorized that the birds are feral descendants of escapees from the Moscow Zoo, the population most likely forming after 1948, when the policy of clipping the birds' wings was repealed. Unlike the wild population, these ducks are non-migratory, wintering instead in the non-freezing parts of the city's bodies of water. Population increased from 1990's to 2020's by over 20 times, reaching 3300 by 2025.
This shelduck mostly frequents open locations on inland bodies of water such as lakes, reservoirs and rivers. It is seldom seen in forested areas but does occur in brackish water and saline lagoons. Though more common in the lowlands, it also inhabits higher altitudes and in central Asia is one of the few waterbirds, along with the bar-headed goose ( Anser indicus), to be found on lakes at .
The ruddy shelduck is usually found in pairs or small groups and rarely forms large flocks. However, moulting and wintering gatherings on chosen lakes or slow rivers can be very large. Gatherings of over four thousand birds have been recorded on the Koshi Barrage and in the Koshi Tappu Wildlife Reserve in Nepal, and over ten thousand at Lake Düden in Turkey.
The birds arrive at their main breeding locations in central Asia in March and April. There is a strong pair bond between the male and female and it is thought they pair for life. In their breeding quarters, the birds 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 round him, inciting him to attack. He may or may not do so. Mating takes place on the water after a brief courtship ritual involving 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.
A clutch of about eight eggs (range six to twelve) is laid between late April and early June. These have a dull gloss and are creamy-white, averaging . Egg incubation is done by the female while the male stands in attendance nearby. The eggs hatch after about twenty-eight days and both parents care for the young, which fledge in a further fifty-five days. After breeding the adults Moulting, losing the power of flight for about a month while they do so. Before moulting 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 breed about five weeks earlier, and their breeding success is greater in wet summers.
The ruddy shelduck has a very wide range and an estimated total population size of 170,000 to 225,000 individuals. The overall population trend is unclear as some local populations are increasing while others are decreasing. The bird does not appear to meet the higher criteria necessary to be considered threatened, and the International Union for Conservation of Nature assesses that its conservation status is of least concern. It is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
Description
Distribution and habitat
Behaviour
Status
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