Tadorna ferruginea¹ is a member of the Tadorna family which is composed of a large number of goose-like waterfowl, recognised as semi-terrestrial long-necked birds.

There are 14 species in the shelduck family. The ruddy shelduck is native to central and eastern Asia, living in various regions inland, often around lagoons, lakes, marshes, rivers and streams. It is regularly found in hills up to 5,000m.

Taxonomy

Like all living organisms, the ruddy shelduck is classified according to its physical characteristics. This is known as its taxonomy. All birds share the same basic features:

• Kingdom: Animalia.
• Phylum: Chordata.
• Sub-Phylum: Vertebrata.
• Class: Aves.
• Order: Anseriformes.
• Family: Anatidae.
• Sub-Family: Tadorninae.
• Genus: Tadorna.

The ruddy shelduck is a rust-coloured bird that appears as a cross between a duck and a goose, measuring 61-67cm when full grown, and with a wingspan of 121-124cm.

The male is a cinnamon-rust colour with a pale buff head and black neck ring, black bill, and black short-toed webbed feet. It has a distinct black rump and tail, which is prominent in flight as is the white inner wing. The female has similar plumage, except the head is almost white, with no neck ring.

Once the breeding season is over, male waterfowl lose their bright breeding plumage and adopt a more drab plumage, usually similar to the female's. This period of change - known as being 'in eclipse' - causes the birds to look scruffy and in many cases lose their waterproofing, so they have to hide to avoid predators. The drab plumage also helps them blend into the less colourful autumn and winter scenery, until the onset of the next breeding season. Male Ruddy Shelduck in this phase lose their black neck ring.

The nest, like those of all shelduck, is usually in a tree hollow. However due to the preferred habitat, these are not always available; rock crevices, farm or abandoned buildings, sand or clay hollows may also be used. In exceptional circumstances, it will nest in the open.

The nest is normally scantily lined with down, possibly supplemented with grass. There are 8 - 12 white eggs in the clutch, which are incubated by the female for 27 - 29 days.

The adults appear to bond for life.

The ruddy shelduck is omnivorous, primarily feeding on land-based plant material, but will also eat aquatic plant life, upending in the manner of ducks. Other food types are grain and invertebrates.

They are gregarious, becoming very territorial when nesting, often in family groups. Big flocks can occur where large populations exist.

The call is a nasal trumpeting and honking with occasional whining. The female produces a harsher, deeper and more penetrating call, with a rolling aakh and an abrupt pok-pok-pok-pok.

History

Although found throughout the eastern and southern coastal areas, its arrival in the UK is obscure. There have been records of it breeding, although these are probably escaped ornamental birds, rather than wild migrant birds. The nearest recognised breeding colonies to the UK are in NW Africa and southern Spain. There have been migratory influxes, notably in 1892 and 1945/6.

Although there is scant information about the bird nationally, and casual records are submitted from time to time, the bird is believed to be an occasional or rare visitor to the UK, and therefore a species well worth keeping an eye out for. Its first appearance in the UK also seems difficult to pinpoint, but is perceived to be in 1892². It is not thought to have a sustainable breeding population in the UK, with only occasional records, and is not considered to be a threat to native wildlife.

Peculiarly the species is known as shelduck, although the male of the species is known as a sheldrake. This is an unusual example of female-dominant taxonomy!