The population is estimated to number 2,400-2,600 in North Africa; 36,000-54,000 in eastern Europe; 25,000-100,000 in south-west Asia and north-east Africa (based on counts in the 1990s of 9,000 in Azerbaijan, 21,000 in Turkmenistan and 7,000 in Uzbekistan), and over 100,000 in the rest of Asia (based on tens of thousands breeding in Inner Mongolia (Xing Lianlian in litt. 1998), common occurrence on the Tibetan Plateau, and upwards of 90,000 being present on the hoars of north-east Bangladesh in January 2002).
This species's range has fluctuated considerably over the last c.150 years as it has modified its distribution. However, most figures suggest widespread declines. Owing to significant local declines it is classified as Vulnerable in Europe. Evidence of declines in the larger Asian populations is sparse, and sometimes contradictory. The overall population is estimated to be declining at a moderate rate.
Behaviour This species is chiefly migratory (del Hoyo et al. 1992; Scott and Rose 1996), although little is known about its migratory routes (Scott and Rose 1996) and some individuals in southern populations may remain on the breeding grounds all year (Kear 2005b). It breeds from April or May (del Hoyo et al. 1992) until late June (Madge and Burn 1988) in single pairs or loose groups (del Hoyo et al. 1992). Adults undertake a wing moulting period on the breeding grounds between July and August (Robinson and Hughes 2006) when large flocks of moulting individuals may gather (Robinson and Hughes 2006) (no moult migration is recorded however [Scott and Rose 1996]). Departure from the breeding grounds begins in mid- to late-August (N. Petkov in litt. 2008) and peaks in October (Kear 2005b), with the species arriving in wintering areas from late October (Scott and Rose 1996). The return migration to the breeding grounds begins in early March (Scott and Rose 1996). Large gatherings of up to 100 individuals may occur prior to migration at the end of the post-breeding moult (Madge and Burn 1988) (July to August Scott and Rose (1996]), and on migration the species often remains in small groups of 20-50 individuals (N. Petkov in litt. 2008). Outside of the breeding season the species may be observed solitarily, in pairs or small loose groups (Madge and Burn 1988) of 2-5 individuals (Snow and Perrins 1998), and larger gatherings of 1,000-2,000 individuals are also recorded from wintering grounds in Niger and Chad (Petkov et al. 2003). Habitat It shows a strong preference for fresh standing water (Snow and Perrins 1998; N. Petkov in litt. 2008) and is very rarely found on flowing streams or rivers (N. Petkov in litt. 2008). It requires shallow water 30-100 cm deep close to littoral vegetation for feeeding (del Hoyo et al. 1992; Kear 2005b) and generally avoids large open areas (Kear 2005b; Scott and Rose 1996). In Bulgaria there is evidence that the species shows a preference for well-vegetated, comparatively shallow wetlands with well-structured mosaic vegetation and a diversity of microhabitats. It is also found on shallow mudflats, possibly as a result of more accessible and abundant invertebrate food sources in this habitat (Petkov in prep.) Breeding Shallow eutrophic freshwater pools and marshes with dense abundant submergent, floating, emergent and shoreline vegetation (e.g. reedbeds) are the major breeding habitats (del Hoyo et al. 1992; Kear 2005b; N. Petkov in litt. 2008). Shallow banks with flooded vegetation and mudflats are particularly used for foraging during this season. The species shows a particular preference for breeding, moulting and staging on large river deltas (Kear (2005b; Scott and Rose 1996; Robinson and Hughes 2006) and extensively managed fish ponds in Eastern Europe (Petkov 2006; Robinson and Hughes 2006). It is also less-commonly known to utilise brackish waters of estuaries, coastal lagoons, reservoirs, salt-pans, sewage farms, canals and drainage ditches during this season (Snow and Perrins 1998; Robinson and Hughes 2006; N. Petkov in litt. 2008). Non-breeding Its habitat requirements outside of the breeding season are similar to those of the breeding season (Kear 2005b), although it may also frequent large lakes, open lagoons, coastal marshes with reedbeds (del Hoyo et al. 1992; Kear 2005b; Scott and Rose 1996) and shallow coastal bays, straits and estuaries (Robinson and Hughes 2006). Diet Although the species is omnivorous, plant material such as seeds, roots and vegetative parts of aquatic plants (del Hoyo et al. 1992) (Potamogeton spp., Ceratophyllum spp., Scirpus spp., Carex spp. and macroalgae Chara spp. [Kear 2005b]) dominates its diet. Animal matter taken includes worms, molluscs (del Hoyo et al. 1992) (snails [Kear 2005b]), crustaceans, adult and larval insects (del Hoyo et al. 1992) (beetles, chironomids (Kear 2005b), dragonflies, waterbugs, caddisflies, flies [Brown et al. 1982]), amphibians (del Hoyo et al. 1992) (frogs, tadpoles and spawn [Kear 2005b; Brown et al. 1982]) and small fish (del Hoyo et al. 1992) up to 3 cm long (Brown et al. 1982). Breeding site The nest is a low platform (Snow and Perrins 1998) of reeds and other vegetation (del Hoyo et al. 1992) placed on the ground or on an islet or hummock in thick vegetation close to water (Kear 2005b; Johnsgard 1978). Alternatively nests may be placed over water on floating mats of vegetation (Johnsgard 1978) or in dense reedbeds along the shoreline (Kear 2005b; Johnsgard 1978).
The species is threatened by the degradation and destruction of well-vegetated shallow pools and other wetland habitats (Vinicombe 2000; del Hoyo et al. 1992; Kear 2005b; Robinson and Hughes 2006) (e.g. changes to the vegetation community, disruption of water regimes, siltation, and increased water turbidity [Robinson and Hughes 2006]) as a result of excessive drainage and water abstraction (Vinicombe 2000; Grishanov 2006; Robinson and Hughes 2006), peat extraction (Grishanov 2006), eutrophication (from inadequate sewage treatment and nutrient run-off [Robinson and Hughes 2006]), oil pollution (Grishanov 2006), dam and barrage construction, the building of infrastructure on flood-plains (Vinicombe 2000; Robinson and Hughes 2006) and river canalisation (Kear 2005b). Changing land management practices such as reed cutting and burning during the breeding season (Petkov 2006), over-grazing (Robinson and Hughes 2006) decreased grazing and mowing of wet meadows (Grishanov 2006), and abandonment (causing succession to scrub) or intensification (causing reversion to open water) of extensively managed fishponds (Vinicombe 2000; Kear 2005b; Petkov 2006; Robinson and Hughes 2006) also threatens the species. The introduction of non-native species has caused further habitat degradation. For example the stocking of lakes with and accidental introduction of Grass Carp Ctenopharyngodon idella has resulted in reductions in macrophyte biomass and corresponding reductions in invertebrate biomass (Kear 2005b; Robinson and Hughes 2006), and in Bulgaria an introduced shrub (Desert False Indigo Amorpha fruticosa) is changing the ecological character of wetlands (Robinson and Hughes 2006). Introduced predators such as the Wels Catfish Silurus glanis (Kazakhstan) that predate ducklings, and the Muskrat Ondatra zibethicus (Aral Sea region) have also caused population declines (Robinson and Hughes 2006). Increased drought due to global climate change may pose a threat to the species in part of its range (Vinicombe 2000; Robinson and Hughes 2006). Disturbance by fishing boats and anglers alongside fringe vegetation could cause abandonment of the breeding sites or disrupt the timing of breeding (N. Petkov in litt. 2008). Hunting is another serious threat to the species (Vinicombe 2000; del Hoyo et al. 1992; Robinson and Hughes 2006). Large numbers are shot on passage in the autumn (e.g. through the Volga delta) and on the wintering grounds (e.g. Sudan) (Kear 2005b; Balmaki and Barati 2006). Illegal and accidental hunting also persists in most European countries. Other lower-level threats include lead poisoning (from ingestion of discarded lead shot), fires in areas of reed thickets, peat bogs and woods (Grishanov 2006) and entanglement and drowning in fishing nets (Robinson and Hughes 2006) and hybridisation with native species (e.g. Tufted Duck Aythya fuligula and Common Pochard Aythya ferina in Switzerland [Leuzinger 2010]).
Conservation actions underway
The species is fully protected in Belarus, Bulgaria, Czech Republic, France, Germany, Hungary, Italy, Moldova, Netherlands, Russia, Slovakia, Slovenia, Spain and Switzerland, and is protected from hunting in Austria, Belgium, Greece, Poland, Turkey and Ukraine. It is listed on Annex I of the European Union Directive on the Conservation of Wild Birds, on Appendix III of the Bern Convention and on Appendices I and II of the Bonn Convention. The species has received little international conservation action, although a number of national initiatives have been developed recently, notably habitat management in Bulgaria and re-introduction schemes in Italy (Berezovikov and Samusev 1998). One of the highest priorities for this species is to establish systematic annual monitoring of Asian populations to more accurately assess trends. Such monitoring, if it provided evidence of continuing and significant declines across major Asian populations, could provide reason to uplist this species. An International Single Species Action Plan has been adopted by the Bern Convention, CMS and AEWA, which lays out a framework for conservation action throughout the specie's range (Robinson and Callaghan 2003). A restoration project for two key breeding sites on the Danube in Bulgaria is underway, funded by the World Bank (N. Petkov in litt. 2003).
Conservation actions proposed
Promote the full legal protection of A. nyroca and its habitat through national and international legislation; promote environmentally friendly management of fishponds in Eastern Europe; promote adequate protection and management of key sites; promote conservation in the wider environment for the benefit of A. nyroca and its habitat; prevent mortality and disturbance caused by hunting; monitor the remaining population (particularly in Asia)and develop census techniques; investigate productivity and mortality; investigate ecology and limiting factors; investigate the impact of C. idella on the species and its habitat; develop and implement education programmes for the conservation of A. nyroca and its habitats.
Related state of the world's birds case studies
Johnsgard, P. A. 1978. Ducks, geese and swans of the World. University of Nebraska Press, Lincoln and London.
Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, London.
Madge, S.; Burn, H. 1988. Wildfowl. Christopher Helm, London.
del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.
Carboneras, C. 1992. Anatidae (Ducks, Geese, and Swans). In: del Hoyo, J.; Elliott, A.; Sargatal, J. (ed.), Handbook of the birds of the world, pp. 536-628. Lynx Edicions, Barcelona, Spain.
Scott, D. A. 1993. The Black-necked Cranes Grus nigricollis of Ruoergai Marshes, Sichuan, China. Bird Conservation International 3: 245-259.
Tucker, G. M.; Heath, M. F. 1994. Birds in Europe: their conservation status. BirdLife International, Cambridge, U.K.
Perennou, C. P.; Mundkur, T.; Scott, D. A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB and AWB, Slimbridge and Kuala Lumpur.
Scott, D. A.; Rose, P. M. 1996. Atlas of Anatidae populations in Africa and western Eurasia. Wetlands International, Wageningen, Netherlands.
Kashkarov, D.; Mukhina, E. 1997. Status of the Ferruginous Duck in Uzbekistan. TWSG News 10: 21-24.
Snow, D. W.; Perrins, C. M. 1998. The Birds of the Western Palearctic vol. 1: Non-Passerines. Oxford University Press, Oxford.
Berezovikov, N. N.; Samusev, I. F. 1998. The Ferruginous Duck in the upper reaches of the Irtysh river. Casarca.
Callaghan, D. A. 1999. European Union Species Action Plan: Ferruginous Duck (Althea nervosa). Council of Europe Publishing, Strasbourg.
Vinicombe, K. E. 2000. Identification of Ferruginous Duck and its status in Britain and Ireland. British Birds 93: 4-21.
Petkov, N.; Hughes, B.; Gallo-Orsi, U. 2003. Ferruginous Duck: from research to conservation. Birdlife International-RSPB-TWSG, Sofia, Bulgaria.
Robinson, J. A.; Hughes, B. 2003. International Species Review: Ferruginous Duck Aythya nyroca.
Robinson, J. A.; Hughes, B. 2003. The global status and distribution of the ferruginous duck. In: Petkov, N.; Hughes, B.; Gallo-Orsi, U. (ed.), Ferruginous duck: from research to conservation, pp. 8-17. BirdLife International-BSBP-TWSG, Sofia.
Robinson, J. A.; Callaghan, D. A. 2003. The ferruginous duck as a Near Threatened species: problems, causes and solutions. In: Petkov, N.; Hughes, B.; Gallo-Orsi, U. (ed.), Ferruginous duck: from research to conservation, pp. 138-143. BirdLife International-BSBP-TWSG, Sofia.
Sultanov, E.; Agayeva, N. 2003. The current breeding status of Ferruginous Duck Aythya nyroca in Azerbaijan. Sandgrouse 25: 41-49.
BirdLife International. 2004. Birds in Europe: population estimates, trends and conservation status. BirdLife International, Cambridge, U.K.
Kear, J. 2005. Ducks, geese and swans volume 2: species accounts (Cairina to Mergus). Oxford University Press, Oxford, U.K.
Petkov, N. 2006. he importance of extensive fishponds for Ferruginous Duck Aythya nyroca conservation. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 733-734. The Stationary Office, Edinburgh, UK.
Robinson, J. A.; Hughes, B. 2006. International single species action plan for the conservation of the Ferruginous Duck Aythya nyroca. CMS/AEWA, Bonn, Germany.
Balmaki, B.; Barati, A. 2006. Harvesting status of migratory waterfowl in northern Iran: a case study from Gilan Province. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 868-869. The Stationary Office, Edinburgh, UK.
Grishanov, D. 2006. Conservation problems of migratory waterfowl and shorebirds and their habitats in the Kaliningrad region of Russia. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 356. The Stationary Office, Edinburgh, UK.
Petkov, N. in prep. Wetland Characteristics of the breeding sites of the Ferruginous Duck Aythya nyroca and Common Pochard Aythya farina and its implication on their distribution and conservation status.
Further web sources of information
African-Eurasian Waterbird Agreement (AEWA) International Action Plan 2006
Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).
Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.
International Action Plan
International Species Review
View photos and videos, and hear sounds of this species from the Internet Bird Collection
Text account compilers
Benstead, P., Capper, D., Derhé, M., Harding, M., Malpas, L., O'Brien, A., Peet, N., Pilgrim, J.
Baral, H., Braunlich, A., Brouwer, J., Halder, R., Hatzofe, O., Heinicke, T., Hughes, B., Inskipp, C., Isfendiyaroglu, S., Jayadevan, P., Katzner, T., Khan, A., Liu Dongping, .., Mischenko, A., Parveen, A., Petkov, N., Sklyarenko, S., Subramanya, S., Tordoff, A., Xing Lianlian, .., Yasmeen, R., Yerokhov, S.
IUCN Red List evaluators
Butchart, S., Symes, A.
BirdLife International (2013) Species factsheet: Aythya nyroca. Downloaded from
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Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from
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This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
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