Ruddy shelduck

Tadorna ferruginea

Rode casarca / Rostgans / Casarca roux

The Ruddy shelduck is a member of the waterfowl family Anatidae, in the shelduck subfamily Tadorninae. Although becoming quite rare in southeast 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 birds. Although this bird is observed in the wild from time to time in eastern North America, no evidence of a genuine vagrant has been found.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2012).

The global population is estimated to number c.170,000-220,000 individuals (Wetlands International 2006), while national population sizes have been estimated at c.100-10,000 breeding pairs and c.50-1,000 wintering individuals in China and c.50-10,000 wintering individuals in Korea (Brazil 2009).

Hunting is a threat, especially in south-east Europe (Johnsgard 1978, del Hoyo et al.1992, Kear 2005a, Popovkina 2006) (e.g. in Turkey) (Scott and Rose 1996), although the species is largely protected in central and eastern Asia by its sacred status (Kear 2005a). Other threats to western populations include the loss and degradation of inland wetlands through subterranean water extraction for irrigation (Popovkina 2006) (leading to decreasing water supplies for seasonal and semi-permanent wetlands), widespread drainage of shallow marshes and lakes (Scott and Rose 1996), salt extraction (del Hoyoet al. 1992, Green et al. 2002, Popovkina 2006), urban development, pollution, introduction of exotic fish and overgrazing (del Hoyo et al. 1992, Green et al. 2002, Popovkina 2006). At the Klingnau Dam in northern Switzerland the species has been known to hybridise with the South African Shelduck Tadorna cana from escaped captive populations, which could pose a threat to the integrity of both species (Owen et al. 2006). The species is also susceptible to avian influenza (strain H5N1) and is therefore threatened by outbreaks of the virus (Melville and Shortridge 2006). This species is hunted for commercial and recreational purposes in Gilan Province, northern Iran (Balmaki and Barati 2006).

Captive breeding management

By Dan Cowell

This large duck is very common in aviaries and easy to keep and raise. When seen from a distance, the sexes appear similar, but closer observation reveals that the males have a black neck ring and hens have a white face. The overall color is orange blended with brown and chestnut; they have white wing coverts, metallic green speculum and black primaries and tail. The bill and feet are black.
They are very similar to the Cape shelduck (Tadorna cana) and I have even read that some orinthologists have classed the Cape shelduck as a subspecies of the Ruddy. While they are very similar in appearance and behavior, most recognize the Cape as a seperate species.
Breeding this duck is not difficult. They do require an burrow-type nest box to lay the clutch of 8 to 16 eggs. I have noticed that this species begins to lay earlier than most waterfowl. I remember the hen starting in early March last season, while there was still snow on the ground! The hen will pull lots of down to line the nest, but I also provide plenty of pine shavings as nesting material. Incubation lasts about 28 days. You can allow the hen to hatch her own eggs, and both of the adults make good parents. Sometimes the male is more protective over the brood than the hen!
Young birds may not breed until their second year. The immatures are similar to the adults, but are paler and have gray markings on the wings.
While they are considered great ducks for the beginner, they are very aggressive towards other species of waterfowl and may need to be housed in their own aviary. I had a small green-wing teal hen make the mistake of entering the aviary where the Ruddy pair was nesting. When I found her that afternoon, the only means of identifying the teal was by her leg band. I have also seen them spar with the related Egyptian Goose (Alopchen aegyptiacus) through the sides of an adjoining aviary!
Ruddy shelducks have a very loud call that can be heard from quite a distance. Males honk, almost like a goose and hens make a louder 'Ka-ha-ha'. They do very well in captivity, but require a larger aviary than other species of waterfowl. They are very hardy and can withstand very cold temperatures.

Tadorna ferruginea, male

Tadorna ferruginea, female

Above: adult female Ruddy shelduck

Above: adult female Ruddy shelduck

Above: adult female Ruddy shelduck