Justification Given that this species's range may fluctuate considerably from year to year - particularly in Asia - owing to changing water levels, it is very hard to estimate the global population or trends. There have been rapid declines in Europe, but evidence of declines in the larger Asian populations is sparse, and sometimes contradictory, so it is currently listed as Near Threatened. Evidence of rapid declines in Asia would qualify the species for uplisting to Vulnerable.

Family/Sub-family Anatidae

Species name author (Güldenstädt, 1770)

Taxonomic source(s) AERC TAC (2003), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), Sibley and Monroe (1990, 1993)

Identification 38-42 cm. Dark chestnut coloured diving duck. Both sexes uniform chestnut, slightly darker on back with white belly and undertail; male with distinctive pale iris. Juvenile similar but belly and undertail grey-buff. In flight a broad white wingbar extends onto outer primaries. Similar spp. Easily distinguished from other Aythya ducks by white undertail when sitting and extensive wingbar in flight. Voice In spring female noisy in flight with err, err... call and male with a short chuk call. Hints Prefers shallower and more vegetated areas than other Aythya species and seldom sits out on open water. Outside of main range search flocks of other diving ducks.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

160,000 - 257,000

decreasing

3,610,000 km²

No

Range & population Aythya nyroca breeds principally in south-western Asia (east to China and south to Pakistan and India), central and eastern Europe, and north Africa⁹. The wintering range overlaps with the breeding range and extends to the Middle East, north-east and West Africa (mainly Mali and Nigeria⁹) and South-East Asia. Four main populations are recognised and migration occurs from early September to mid-October, whilst breeding grounds are re-occupied from mid-March to early May⁹. The main part of the population occurs in Asia, where there is much suitable habitat and it remains common, although quantitative data are lacking. Given that this species's range may fluctuate considerably from year to year, owing to changing water levels, it is unclear how much one-off high counts from Asian countries represent just one mobile population²². The current global population is estimated at c.163,000-257,000 individuals. An estimate for North Africa and Asia of 10,000 individuals in 1991⁴ appears too low. About 600 pairs breed in the El Kala National Park, Algeria⁹. In Europe the breeding population is estimated at 12,000-18,000 pairs with the largest population in Romania (5,500-6,500 breeding pairs, concentrated in the Danube Delta)^{14, 15}. Significant populations (between 1,000 and 5,000 pairs) are also found in Croatia, Azerbaijan, and possibly Turkey, whilst smaller populations (c.500-1,000 pairs) are found in Russia, Hungary, and possibly Serbia and Ukraine^14,15. Populations in most European countries are showing signs of continuing large-scale declines. Sporadic breeding and/or wintering occurs in several western European countries. In Asia recent surveys have found high numbers, perhaps into the tens of thousands, in Inner Mongolia⁶ (although the accuracy of these counts is unclear, and may refer to non-breeding birds from other areas), 6,000-7,000 breeding pairs in Kazakhstan²⁷ (although others have suggested it is uncommon^17,20) and it is apparently common on the Tibetan Plateau, China⁵, and in winter in India, Bangladesh (70,000 birds counted at one group of four sites)¹¹, Myanmar and Thailand. Other large winter counts have been made in Azerbaijan (9,000 birds), Turkmenistan (21,000 birds)² and Uzbekistan (7,000 birds³, but recently less²⁷). Small numbers occur on passage in Lebanon and Qatar and also in winter in Iraq, Israel, Jordan, Oman, Saudi Arabia, Syria, United Arab Emirates and Yemen. The species has declined markedly in Europe where there have been declines of more than 20% in eight European countries^{14, 15}. The status of the European population (12,000-18,000 pairs, occupying 25-49% of the global breeding range) was recently reassessed^{14, 15}. Following a large decline in Europe during 1970-1990²⁶, the species continued to decline during 1990-2000, when up to 45% of birds appear to have been lost (particularly in south-east Europe). The European population is believed to have declined overall by ^{14, 15}. There is also some evidence for declines in the number of birds in India^19,24, Kazakhstan^1,23 (although other evidence suggests that this population is actually stable²⁷), Kyrgyzstan¹⁷, Pakistan²¹, Uzbekistan^3,23 (but this population may have now stabilised²⁷) and Vietnam²⁵, and to a minor degree in Nepal¹⁷ (but possibly stable there¹³). Winter counts from Israel suggest that population to be generally stable in recent years¹⁶. In Ukraine, numbers have fallen from an estimated 65,000 in the late 1960s⁹ to an estimated 1,500 pairs, whilst declines have also been recorded in Moldova, Albania (from 100-300 pairs to a recent estimate of 0-3 pairs¹⁰), Poland, Hungary, and Spain (from c.500 pairs 100 years ago to five pairs in recent years)⁹. However, populations remain stable in a number of other countries and slight local increases may have occurred in parts of Russia and Ukraine since hunting has diminished due to the species's rarity⁹. This species's range has fluctuated considerably over the last c.150 years, although the overall trend has been towards a declining population and distribution. 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, and so there is insufficient evidence at present to warrant uplisting to Vulnerable globally.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Behaviour This species is chiefly migratory^28,30, although little is known about its migratory routes³⁰ and some individuals in southern populations may remain on the breeding grounds all year²⁹. It breeds from April or May²⁸ until late June³¹ in single pairs or loose groups²⁸. Adults undertake a wing moulting period on the breeding grounds between July and August³⁸ when large flocks of moulting individuals may gather³⁸ (no moult migration is recorded however)³⁰. Departure from the breeding grounds begins in mid- to late-August⁴⁰ and peaks in October²⁹, with the species arriving in wintering areas from late October³⁰. The return migration to the breeding grounds begins in early March³⁰. Large gatherings of up to 100 individuals may occur prior to migration at the end of the post-breeding moult³¹ (July to August)³⁰, and on migration the species often remains in small groups of 20-50 individuals⁴⁰. Outside of the breeding season the species may be observed solitarily, in pairs or small loose groups³¹ of 2-5 individuals³³, and larger gatherings of 1,000-2,000 individuals are also recorded from wintering grounds in Niger and Chad²². Habitat It shows a strong preference for fresh standing water^33,40 and is very rarely found on flowing streams or rivers⁴⁰. It requires shallow water 30-100 cm deep close to littoral vegetation for feeeding^28,29 and generally avoids large open areas^29,30. 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 habitat⁴¹. Breeding Shallow eutrophic freshwater pools and marshes with dense abundant submergent, floating, emergent and shoreline vegetation (e.g. reedbeds) are the major breeding habitats^28,29,40. 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^29,30,38 and extensively managed fish ponds in Eastern Europe^37,38. 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^33,38,40. Non-breeding Its habitat requirements outside of the breeding season are similar to those of the breeding season²⁹, although it may also frequent large lakes, open lagoons, coastal marshes with reedbeds^28,29,30 and shallow coastal bays, straits and estuaries³⁸. Diet Although the species is omnivorous, plant material such as seeds, roots and vegetative parts of aquatic plants²⁸ (Potamogeton spp., Ceratophyllum spp., Scirpus spp., Carex spp. and macroalgae Chara spp.)²⁹ dominates its diet. Animal matter taken includes worms, molluscs²⁸ (snails)²⁹, crustaceans, adult and larval insects²⁸ (beetles, chironomids²⁹, dragonflies, waterbugs, caddisflies, flies³⁴), amphibians²⁸ (frogs, tadpoles and spawn)^29,34 and small fish²⁸ up to 3 cm long³⁴. Breeding site The nest is a low platform³³ of reeds and other vegetation²⁸ placed on the ground or on an islet or hummock in thick vegetation close to water^29,32. Alternatively nests may be placed over water on floating mats of vegetation³² or in dense reedbeds along the shoreline^29,32.

Threats The species is threatened by the degradation and destruction of well-vegetated shallow pools and other wetland habitats^9,38,28,29 (e.g. changes to the vegetation community, disruption of water regimes, siltation, and increased water turbidity)³⁸ as a result of excessive drainage and water abstraction^9,35,38, peat extraction³⁵, eutrophication (from inadequate sewage treatment and nutrient run-off)³⁸, oil pollution³⁵, dam and barrage construction, the building of infrastructure on flood-plains^9,38 and river canalisation²⁹. Changing land management practices such as reed cutting and burning during the breeding season³⁷, over-grazing³⁸, decreased grazing and mowing of wet meadows³⁵, and abandonment (causing succession to scrub) or intensification (causing reversion to open water) of extensively managed fishponds^9,29,37,38 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^29,38, and in Bulgaria an introduced shrub (Desert False Indigo Amorpha fruticosa) is changing the ecological character of wetlands³⁸. Introduced predators such as the Wels Catfish Silurus glanis (Kazakhstan) that predates ducklings, and the Muskrat Ondatra zibethicus (Aral Sea region) have also caused population declines³⁸. Increased drought due to global climate change may pose a threat to the species in part of its range^9,38. Disturbance by fishing boats and anglers alongside fringe vegetation could cause abandonment of the breeding sites or disrupt the timing of breeding⁴⁰. Hunting is another serious threat to the species^9,28,38. Large numbers are shot on passage in the autumn (e.g. through the Volga delta) and on the wintering grounds (e.g. Sudan)^29,36. Illegal and accidental hunting also persists in most European countries. Other lower-level threats include lead poisoning (from ingestion of discarded lead shot), and entanglement and drowning in fishing nets³⁸.

Conservation measures 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 Italy¹. 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 out a framework for conservation action throughout the specie's range⁸. A restoration project for two key breeding sites on the Danube in Bulgaria is underway, funded by the World Bank¹⁰.

Conservation measures 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.

References Callaghan (1999). 1. Berezovikov and Samusev (1998). 2. Carboneras (1992a). 3. Kashkarov and Mukhina (1997). 4. Perennou et al. (1994). 5. Scott (1993). 6. Xing Lianlian pers. comm. (1998). 7. Robinson and Hughes (2003) 8. Robinson and Callaghan (2003). 9. Vinicombe (2000). 10. N. Petkov in litt. (2003). 11. R. Halder in litt. (2002). 12. Sultanov and Agayeva (2003). 13. H. S. Baral in litt. (2005). 14. BirdLife International (2004). 15. O. Hatzofe in litt. (2005). 16. T. Heinicke in litt. (2005). 17. C. Inskipp in litt. (2005). 18. P. Jayadevan in litt. (2006). 19. T. Katzner in litt. (2005). 20. A. A. Khan in litt. (2006). 21. N. Petkov in litt. (2005). 22. Petkov et al. (2003). 23. S. Subramanya in litt. (2006). 24. A. W. Tordoff in litt. (2005). 25. Tucker and Heath (1994). 26. Unpublished expert communications to S. Sklyarenko (2005). 27. S. Yerokhov verbally per N. Petkov in litt. (2005). 28. del Hoyo et al. (1992). 29. Kear (2005b). 30. Scott and Rose (1996). 31. Madge and Burn (1988). 32. Johnsgard (1978). 33. Snow and Perrins (1998). 34. Brown et al. (1982). 35. Grishanov (2006). 36. Balmaki and Barati (2006). 37. Petkov (2006). 38. Robinson and Hughes (2006). 39. J. Brouwer in litt. (1999). 40. N. Petkov in litt. (2008). 41. Petkov (in prep.).

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)

Fully detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001), together with new information collated since the publication of the Red Data Book

International Action Plan

International Species Review

Text account compilers Phil Benstead (BirdLife International), David Capper (BirdLife International), Matt Harding (BirdLife International), Lucy Malpas (BirdLife International), Andrew O'Brien (BirdLife International), Mark O'Brien (Royal Society for the Protection of Birds), Nic Peet (BirdLife International), John Pilgrim (BirdLife International)

Contributors Hem Sagar Baral (Bird Conservation Nepal), Axel Braunlich, Ronald Halder (Nature Conservation Committee), Ohad Hatzofe (Israel Nature and Parks Authority), Thomas Heinicke, Baz Hughes (Wildfowl and Wetlands Trust), Carol Inskipp, Süreyya Isfendiyaroglu (Doga Dernegi), Praveen Jayadevan, Todd Katzner (National Aviary), Aleem Ahmed Khan (Ornithological Society of Pakistan), . Liu Dongping (Anatidae Task force), Alexander L. Mischenko (Russian Bird Conservation Union), Abida Parveen (Ornithological Society of Pakistan), Nicky Petkov (Bulgarian Society for the Protection of Birds), S. Subramanya (Indian Birds), A. W. Tordoff (BirdLife International in Indochina), . Xing Lianlian, Rafat Yasmeen (Ornithological Society of Pakistan)

IUCN Red List evaluators Ian Burfield (BirdLife International - European Division), Stuart Butchart (BirdLife International), Mike Crosby (BirdLife International), James Gilroy (BirdLife International), John Pilgrim (BirdLife International), Rob Pople (BirdLife International - European Division)

Recommended citation BirdLife International (2009) Species factsheet: Aythya nyroca. Downloaded from http://www.birdlife.org on 10/2/2010

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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