Justification This species has been uplisted to Endangered owing to an apparant accelleration in the rate of its decline, as measured by numbers on the wintering grounds. It is now absent or occurs in greatly reduced numbers over much of its former wintering grounds and is common nowhere. It is thought that hunting and wetland destruction are the key reasons for its decline.

Family/Sub-family Anatidae

Species name author (Radde, 1863)

Taxonomic source(s) Sibley and Monroe (1990, 1993)

Identification 41-46 cm. Pale-eyed diving duck. Similar spp. Males are best told from other Aythya ducks by combination of blackish head, upper neck and upperparts, whitish eyes and chestnut-brown and white flanks. In flight, wing pattern like Ferruginous Duck A. nyroca, but white upperwing-band does not extend as far onto outer primaries. Eclipse male resembles female, but retains whitish eyes. Female has combination of domed head without nuchal tuft, contrast between dark head and warm brown breast and white on foreflanks, ruling out A. nyroca and A. fuligula. Juvenile resembles female, but more chestnut-tinged head with darker crown and hindneck and no defined loral patch.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

5,000

decreasing

1,640,000 km²

No

Range & population Aythya baeri breeds in the Amur and Ussuri basins in Russia and north-eastern China. It winters mainly in eastern and southern mainland China (c. 850 individuals)¹, India, Bangladesh (1,000 - 2,000 individuals)² and Myanmar (1,000 - 1,500 individuals)³ with smaller numbers in Japan, North Korea, South Korea (very few records in the latter three countries in recent years)⁴, Hong Kong (China), Taiwan (China), Nepal (now a very rare visitor and absent in some years)⁵, Bhutan, Thailand (still regular in small numbers, Bung Khong Long is the only site which still has double figure counts)⁶, Lao PDR (only one confirmed record)⁶, and Vietnam (very rare in recent years)⁶ and is a rare migrant to Mongolia. It has declined rapidly in recent years, for instance at Bung Boraphet, Thailand, up to 426 were recorded in 1988 whilst now there are more usually four or five individuals⁷. The total population is now likely to be less than 5,000 individuals¹.

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

Ecology: It breeds around lakes with rich aquatic vegetation in dense grass or flooded tussock/shrubby meadows. In Liaoning, China, it is usually found in coastal wetlands with dense vegetation, or on rivers and ponds surrounded by forest. The nest is built on a tussock or under shrubs, sometimes floating, and occasionally amongst branches. In winter, it occurs on freshwater lakes and reservoirs.

Threats Threats are poorly understood, but hunting and wetland destruction in its breeding and wintering grounds are probably the reasons for its decline.

Conservation measures underway CMS Appendix II. It is legally protected in Russia, Mongolia and Hong Kong (China) and in some provinces in China. Some of its breeding and wintering sites are within protected areas, including Daursky, Khanka lake and Bolon lake (Russia), Sanjiang and Xianghai (China), Mai Po (Hong Kong), Koshi Barrage (Nepal), and Thale Noi (Thailand).

Conservation measures proposed Research its population, distribution, ecology and threats in order to produce conservation recommendations. Establish more protected areas in its breeding grounds. Extend the area of the Khanka Lake Reserve (Russia). Designate the Xianghai Nature Reserve (China) as a restricted area during the breeding season. Regulate hunting of all Anatidae species in China. Ensure legal protection of this species in all range states.

References BirdLife International (2001). 1. M. Barter in litt. (2007). 2. P. Thompson in litt. (2005). 3. G. Chunkino in litt. (2007). 4. N. Moores in litt. (2005). 5. H. S. Baral in litt. (2007). 6. J. Tordoff in litt. (2007). 7. P. Round in litt. (2007).

Further web sources of information

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

Text account compilers Phil Benstead (BirdLife International), Simba Chan (Wild Bird Society of Japan), Simon Mahood (BirdLife International), Nic Peet (BirdLife International)

Contributors Bjorn Anderson, Hem Sagar Baral (Bird Conservation Nepal), Mark Barter, Simba Chan (Wild Bird Society of Japan), Gaasas Chunkino, Will Duckworth (Wildlife Conservation Society), Jonathan C Eames (BirdLife International in Indochina), Jesper Hornskov, Zuo Wei David Li (Wetlands International), Nial Moores (UPO Wetlands Centre), P. Round, Paul Thompson (Flood Hazard Research Centre), Jack Tordoff (BirdLife International)

IUCN Red List evaluators Stuart Butchart (BirdLife International), Simon Mahood (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Aythya baeri. 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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