Baers Pochard (Aythya baeri)

[order] ANSERIFORMES | [family] Anatidae | [latin] Aythya baeri | [authority] Radde, 1863 | [UK] Baers Pochard | [FR] Fuligule de Baer | [DE] Baer-Moorente | [ES] Porron de Baer | [NL] Baers Witoogeend

Subspecies

Genus

Physical charateristics

Pale-eyed diving duck. 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.

Range

Eurasia : East. 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), India, Bangladesh (1,000 – 2,000 individuals) and Myanmar (1,000 – 1,500 individuals) with smaller numbers in Japan, North Korea, South Korea (very few records in the latter three countries in recent years), Hong Kong (China), Taiwan (China), Nepal (now a very rare visitor and absent in some years), Bhutan, Thailand (still regular in small numbers, Bung Khong Long is the only site which still has double figure counts), Lao PDR (only one confirmed record), and Vietnam (very rare in recent years)6 and is a rare migrant to Mongolia.

Habitat

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.

Reproduction

Males and females form pair bonds shortly after arriving at the breeding grounds from mid April onwards. The first eggs are laid in May, the last in June, clutch is 9 and 15 eggs. The nests are often built in loose colonies sometimes with other species. Some females will lay their eggs in the nests of the common pochard and the gadwall, this may be ineffective, as the common pochard is known to lay her eggs in the nests of Baer?s pochards. Incubation lasts between 23 and 28 days and is caaried out by the female alone. The male will guard her and feed them both. In undisturbed areas the chicks that hatch first will remain close to the nest until all the eggs have hatched, but if disturbed the parents are likely to abandon the remaining eggs and move the hatchlings away from the nest. The ducklings are looked after by both parents for two or three weeks before they learn to dive and forage alone. The adults leave to moult, the ducklings form new flocks.

Feeding habits

An accomplished diver, Baer?s pochard can stay submerged for around 40 seconds, reaching a depth of about two metres whilst looking for insects, molluscs, shrimps, fish and algae during the breeding season, and aquatic plants and seeds during migration and the winter season

Video Baers Pochard

httpv://www.youtube.com/watch?v=E3KYCYJiNqI

copyright: Josep del Hoyo

Conservation

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.
Shockingly, surveys have shown that around half of the total wintering wildfowl of the middle and lower basins of the Yangtze River were killed each year by hunters through netting, shooting and poisoning. This indiscriminate loss of birdlife impacts not only on those birds that are already deemed to be under threat, but all other birds in the area. Whilst some Aythya species are not as vulnerable as the Baer?s pochard, hunters are usually unable to distinguish between them anyway, and so cannot spare those individuals that may prove to be so important in maintaining a viable population of Baer?s pochard. Eggs are also collected from nests, and as well as the obvious drop in reproductive output this causes, the breeding grounds become less suitable as a result of the disturbance, causing other nests to be abandoned. The drainage of wetlands and the removal of large quantities of aquatic vegetation to aid fishing have caused a fall in the water level at breeding grounds. This has a continuing impact on many waterbirds, lowering their reproductive output significantly. Pesticide run-off and removal of vegetation has lead to an unbalanced ecosystem in which weed growth and siltation destroys water quality, ultimately reducing the value of Baer?s pochard?s habitat

Migration

The majority of the population migrates to spend the winter in eastern and southern China, northeastern India, Bangladesh, Thailand, and Myanmar. However, groups have been seen either on passage or during winter in many other countries, including Mongolia, Japan, North Korea, South Korea, China, Hong Kong, Taiwan, Pakistan, India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Vietnam, and the Philippines

Distribution map