Justification of Red List Category
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.
The global population is estimated to number c.170,000-220,000 individuals (Wetlands International 2015). The European population is estimated at 17,000-26,500 pairs, which equates to 33,900-53,100 mature individuals (BirdLife International 2015).
The overall population trend is uncertain, as some populations are decreasing, while others have unknown trends (Wetlands International 2015). The European population trend is unknown (BirdLife International 2015).
Behaviour Asian populations are largely migratory, moving south on a broad front to winter at lower latitudes and altitudes in India and south-east Asia (del Hoyo et al. 1992, Scott and Rose 1996). Other populations are chiefly sedentary or dispersive, undertaking local movements linked to the availability of suitable water (moving away from drought-affected areas or to temporary wetlands) (del Hoyo et al. 1992, Scott and Rose 1996). The species is usually found dispersed in pairs during the breeding season, although it may form small nesting groups when desirable nesting sites are close together (Madge and Burn 1988). It may congregate into larger flocks (e.g. 4,000 birds at a site in Nepal, > 10,000 at a site in Turkey) during the autumn and winter, but is more characteristically found in scattered small flocks along rivers (Madge and Burn 1988, Kear 2005a). Adults undergo a complete moult after breeding that leaves them flightless for around four weeks mid-July to September (Cramp and Simmons 1977, Kear, 2005a), throughout which they require large open areas of water on or near their breeding grounds (Scott and Rose 1996). The species is mainly nocturnal (Johnsgard 1978). Habitat Breeding This species frequents the shores of inland freshwater, saline and brackish lakes and rivers in open country, particularly those in open steppe, upland plateau and mountainous regions (reaching up to 5,000 m in Himalayas) (Cramp and Simmons 1977, Johnsgard, 1978, Brown et al. 1982, del Hoyo et al. 1992, Quan et al. 2001). However, it is less dependent upon large water bodies for resting and feeding than most other Anatidae, and often occurs a considerable distance from water during the breeding season (Scott and Rose 1996). Non-breeding In the non-breeding season this species prefers streams, slow-flowing rivers, freshwater pools, flooded grasslands, marshes and brackish or saline lakes in lowland regions, and is also found on artificial reservoirs (Cramp and Simmons 1977, Johnsgard, 1978, Brown et al. 1982, del Hoyo et al. 1992, Quan et al. 2001) in the vicinity of agricultural lands (Uzbekistan) (Kreuzberg-Mukhina 2006). It avoids coastal waters and tall, dense vegetation or emergent and floating aquatic plants (Madge and Burn 1988). Diet The species is omnivorous, it's diet consisting of tender green shoots and the seeds of terrestrial vegetation, agricultural grains such as millet and wheat, littoral crustaceans such as shrimps, aquatic and terrestrial insects (especially Locusts), aquatic molluscs, small fish, frogs, amphibian spawn and worms (Cramp and Simmons 1977, Johnsgard, 1978, Brown et al. 1982, del Hoyo et al. 1992, Quan et al. 2001). Breeding site Nests are shallow depressions, frequently located far from the water in burrows or holes in sand or clay banks (these can either be natural or excavated by another animal) (Madge and Burn 1988). Other nest sites include abandoned buildings and farm sheds, hollow trees up to 10 m high, crevices in rocks and cliffs and occasionally nest-boxes (Madge and Burn 1988). Management information The population in the Ascania Nova nature reserve, southern Ukraine, has been restored successfully as a result of artificial nest creation, regular feeding, breaking the ice on ponds to provide constant access to water, and raising broods using conspecific, Cairina moschata and Anas platyrhynchos foster parents (Zubko et al. 2001).
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 Hoyo et 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). Utilisation This species is hunted for commercial and recreational purposes in Gilan Province, northern Iran (Balmaki and Barati 2006).
Conservation Actions Underway
CMS Appendix II. EU Birds Directive Annex I. Bern Convention Appendix II. Within Europe, the restoration of habitats, creation of artificial nests and feeding (Popovkina 2006) seems to have benefited this species (Zubko et al. 2001).
Conservation Actions Proposed
The following actions refer to the species's range within Europe only: Conservation priorities for the species include protection from hunting in south-east Europe and further ringing studies to investigate the status of individual populations and their migratory patterns (Kear 2005, Popovkina 2006). The protection of key sites from development and habitat change should be ensured. Research to assess the impacts of hybridisation with Tadorna cana should be undertaken.
Text account compilers
Ashpole, J, Butchart, S., Ekstrom, J., Malpas, L.
BirdLife International (2021) Species factsheet: Tadorna ferruginea. Downloaded from http://www.birdlife.org on 04/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/03/2021.