Mandarin Duck Aix galericulata Scientific name definitions

41–51 cm; male 571–693 g, female 428–608 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); wingspan 68–74 cm (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ). Male has eclipse plumage , but in breeding plumage is completely unmistakable due to orange wing sails and side whiskers: forehead and crown glossy green to purplish, becoming coppery red and white on long nuchal crest, buff cheeks with chestnut ruff on neck-sides and foreneck, mantle and back olive-brown, scapulars glossy blue marked white and black, tertials blue, with orange-buff outer webs, upper breast maroon, lower breast to undertail-coverts white, with black and orange-white bars on flanks, tail brown, glossed green, with long dark blue-green uppertail-coverts; bill red with flesh-pink nail, legs and feet orange-buff and eyes dark brown with yellowish outer ring. Female (and eclipse male) resemble same plumages of A. sponsa but narrower white ring around eye typically extends as line behind it, have different bill pattern (greyish brown with pale orange tip), pale grey head with finely streaked ear-coverts, more heavily spotted underparts, striking white lines on inner secondaries, less clear-cut white throat and paler legs (3 Brown, D. (2010). Wood Duck and Mandarin Duck: identification of females. Birding World. 23(4): 154–155. Close ), although there may be some variation in these features; also have different bill shape. Juvenile resembles female, though female has pinkish bill, and young are more uniformly grey-brown with less distinct face markings and less obviously dappled appearance to upper breast and flanks.

Introduced in Britain and several countries of C Europe, also in USA.

• Wood x Mandarin Duck (hybrid) Aix sponsa x galericulata

Scattered in Russian Ussuriland, Sakhalin I, NE China, Korea, Japan. Continental populations winter in S China.

Pools, lakes , rivers , marshes and swamps surrounded by dense deciduous forest. Has a preference for small islands and waterbodies with abundant emergent vegetation and wooded islets. Generally found below 1500 m (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ), but recorded to at least 2700 m (Ailao Mts, Yunnan) (4 Wu, F., L. Liu, J. Gao, D. Yan, W. Hu, T. Yang, J. Xia, Q. Liu, and X. Yang (2015). Birds of the Ailao Mountains, Yunnan province, China. Forktail 31:47–54. Close ).

Asian population essentially migratory, wintering at lower latitudes in E, C & S China, as well as Korea (where now known also to breed) (5 Duckworth, J.W. and Moores, N. (2008). A re-evaluation of the pre-1948 Korean breeding avifauna: correcting a ‘founder effect’ in perceptions. Forktail 24: 25–47. Close ), Taiwan (which also has resident population) (6 Sun, Y.-H., Bridgman, C.L., Wu, H.-L., Lee, C.-F., Liu, M., Chiang, P.-J. and Chen, C.-C. (2011). Sex ratio and survival of Mandarin Ducks in the Tachia River of central Taiwan. Waterbirds. 34(4): 509–513. Close ) and Honshu (Japan) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), arriving in Ussuriland and on Sakhalin in Mar to early Apr (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Migrants pass through Beidahe (Hebei, NE China) between 9 Sept and 2 Nov in autumn, and 9 Apr to 3 May in spring (7 Williams, M. D., G. J. Carey, D. G. Duff, and X. Weishu (1992). Autumn bird migration at Beidaihe, China, 1986–1990. Forktail 7:3–55. Close ). However, Japanese and British feral birds mostly sedentary. Recent radio-tracking of resident population on Taiwan, involving 35 males (29 adults) and 46 females (41 adults), found that home ranges of both sexes were smaller during the breeding season than outside it (15·2 ± 7·9 km in males versus 16·8 ± 7·3 km), while those of males (8·8 ± 5·9 km) were significantly larger than home ranges of females (4·3 ± 3·2 km) during the breeding season; young females appear to show stronger philopatry than young males, with the longest-recorded movement by any bird being 35 km (8 Sun, Y.-S., Chiu, M.-C., Li, C.-F., Liu, M., Wu, H.-J. and Chiang, P.-J. (2014). The seasonal home range and movements of Mandarin Ducks Aix galericulata on tributaries of the Tachia River, central Taiwan. Forktail. 30: 41–44. Close ). Wild (or presumed) birds have occurred in NE India (Assam Valley, 1901/02; Uttarakhand, Feb 1999; and Manipur, Mar 1934, 1997 and Dec 2013) (9 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close , 10 Kasambe, R. and Singh, R.K.B. (2014). Mandarin Duck Aix galericulata at Loktak Lake, Manipur. Indian Birds. 9(4): 101. Close ), E Nepal (Jan 1990) (11 Gardiner, S. (1991). Mandarin Duck Aix galericulata: a new species for Nepal. Forktail. 6: 87–88. Close ), NE Bangladesh (Jan 1993) (12 Thompson, P. M., W. G. Harvey, D. L. Johnson, D. J. Millin, S. M. A. Rashid, D. A. Scott, C. Stanfield, and J. D. Woolner (1993). Recent notable bird records from Bangladesh. Forktail 9: 13–44. Close ), Bhutan (Mar 2002) (13 Spierenburg, P. (2005). Birds in Bhutan: Status and Distribution. Oriental Bird Club, Bedford, UK. Close ), Burma (Dec 1933), Hong Kong (six records 1958–1984), Hainan, China (Dec 2003) (14 Lee Kwok Shing, Pui Lok, C.B., Lu Gang and Su Wen-ba (2007). Wetland birds of Hainan Island, China: results from winter waterbird surveys 21341343–21341347. Forktail 23: 92–11341. Close ), Laos (Jan 2004, Jan 2005) (15 Duckworth, J.W. (2006). Six species of bird new to Laos. Forktail 22: 147–151. Close ), Philippines (Luzon, Nov–Dec 2013) (16 Robson, C. (2014). From the field. BirdingASIA. 21:121–127. Close ), Vietnam and N Thailand (most records recent) (17 Robson, C. (2000). A Field Guide to the Birds of South-east Asia. New Holland, London, UK. Close , 16 Robson, C. (2014). From the field. BirdingASIA. 21:121–127. Close ), and escapes throughout Europe (where records available from Azores (18 Lever, C. (2005). Naturalised Birds of the World. T. & A.D. Poyser, London, UK. Close ), Iceland, Faeroes, Sweden, Finland, Poland, Czech Republic, Spain (where perhaps breeds in Valencia) (19 Murgui, E. and Valentín, A. (2003). Relacion entre las caracteristicas del paisaje urbano y la comunidad de aves introducidas en la ciudad de Valencia (España) [Relationships between the characteristics of the urban landscape and the introduced bird community in the city of Valencia (Spain)]. Ardeola. 50(2): 201–214. Close , 20 de Juana, E. and el Comité de Rarezas de la Sociedad Española de Ornitología (2002). Observaciones de aves raras en España. Ardeola. 49(1): 141–171. Close , 21 Dies, J.I., Lorenzo, J.A., Gutiérrez, R., García, E., Gorospe, G., Martí-Aledo, J., Gutiérrez, P. and Vidal, C. (2007). Observaciones de aves raras en España, 244445. Ardeola. 54(2): 405–446. Close ), Balearic Is, Canaries (20 de Juana, E. and el Comité de Rarezas de la Sociedad Española de Ornitología (2002). Observaciones de aves raras en España. Ardeola. 49(1): 141–171. Close , 3 Brown, D. (2010). Wood Duck and Mandarin Duck: identification of females. Birding World. 23(4): 154–155. Close ), Italy, Bulgaria, Romania, Belarus and Morocco) (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ) and North America (California) (18 Lever, C. (2005). Naturalised Birds of the World. T. & A.D. Poyser, London, UK. Close ).

Seeds, particularly nuts, acorns, sweet chestnut, beechmast (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) and grain, aquatic plants and animal food (land snails, frogs, tadpoles (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), insects, fish). Invertebrates particularly important in diet of ducklings (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Regularly feeds in flooded rice fields after harvest in Oct (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), but such foraging behaviour is said to occur year-round in Japan and Korea (22 Fujioka, M., S. D. Lee, M. Kurechi, and H. Yoshida (2010). Bird use of rice fields in Korea and Japan. Waterbirds 33(Special Publication 1):8–29. Close ). Feeds both by day (most active early morning and evening) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) and at night by dabbling on water surface and shoreline (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), and by head dipping and upending in shallow waters; rarely dives (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Generally rather quiet, usually vocalizing only when disturbed or in courtship: male calls mainly variations on sharp, rising whistle with a lower, snorting, nasal component, rendered “hwick” or “uib uib” (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), whereas principal call of female is a loud, sharp, single-noted “kett” or “ke”, which might easily be mistaken for a Common Coot (Fulica atra), if bird not seen, as well as a repeated, plaintive “ack”, which can be uttered at rate of up to 53/minute in display (so-called “Coquette call”), sometimes also in flight, with a shorter version when disturbed (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ).

Starts Apr in England and Russia, but apparently not until Jun in Japan (23 Brazil, M. (1991). The Birds of Japan. Christopher Helm, London, UK. Close ); in NE China egg-laying occurred 22 Apr to 11 Jun in one study (24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ). Monogamous but not territorial with pair-bond lasting until late in incubation period, more rarely brood-rearing (typically longer than in A. sponsa), with pair-bonds usually established on wintering grounds (from Sept, mainly Feb–Mar) (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close , 1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). In single pairs; nests mainly in tree hollows, selected by both pair-members, including old woodpecker holes (perhaps especially those of Black Woodpecker Dryocopus martius) (25 Kear, J. (2003). Cavity-nesting ducks: why woodpeckers matter. British Birds. 96(5): 217–233. Close ) but also natural holes and nestboxes (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), up to 15 m above ground (usually to 10 m) (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ); may return to same hole in consecutive seasons and in native range perhaps competes with Mergus merganser and M. squamatus for suitable cavities (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), which may be up to 0·5 km from rivers (26 Mikhailov, K.E. and Shibnev, Y.B. (1998). The threatened and near-threatened birds of northern Ussuriland, south-east Russia, and the role of the Bikin River basin in their conservation. Bird Conservation International. 8(2): 141–171. Close ); rarely nests on ground in dense vegetation, under bush or fallen ground (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ); once in a building in S China (27 Jiang, A.-W. and Cai, J.-F. (2009). A preliminary observation on the breeding nest of Aix galericulata in city building, Guilin, northeast Guangxi. Chinese J. Zool.. 44(3): 135–137. Close ). In England, dependent on natural nest-holes, particularly beech (Fagus silvatica), and nestboxes (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), while competitors for nest-sites in naturalized range include Jackdaws (Corvus monedula), Mergus merganser, Tawny Owls (Strix aluco) and Bucephala clangula (28 Kestenholz, M., Heer, L. and Keller, V. (2005). Etablierte Neozoen in der europäischen Vogelwelt – eine Übersicht. Orn. Beob.. 102: 153–180. Close ). Clutch 7–14 white or buff eggs (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) (occasionally up to 25 (24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ), as result of dump nesting, which is apparently common in England and NE China) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close , 24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ), laid at one-day intervals (exceptionally up to six) (24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ), size 46–55 mm × 41–43 mm, mass (in captivity) 35·5–51·5 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); incubation 28–33 days by female alone (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); chicks  have olive-brown down above, yellowish below, on wings and rump, with grey-purple bill, mass 18–33·5 g (in captivity) when one day old, and hatch synchronously (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); fledging c. 40–45 days, with young cared for entirely by female (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Incidence of intraspecific parasitism recently quantified in NE China, where 46·2% of completed clutches are parasitized and frequency is positively associated with nest density, but declines as the season progressed (as in A. sponsa); on average, c. 2·5 females lay eggs in each parasitized nest, with significant differences in clutch initiation dates and mean laying period between parasitized and unparasitized nests, and clutch size for unparasitized nests decreases with advancing initiation date (24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ). In same study, nest desertion was main cause for egg failures, accounting for 72·8%, followed by non-fertilization (11·4%) and human disturbance (11·1%); other losses were due to embryo death and unknown reasons, while five ducklings in three parasitized nests with large number broods died before leaving the nest, apparently being trampled; the hatching rate for eggs in successful nests was 87·1%, with no significant difference between parasitized and unparasitized nests, while mean numbers of ducklings leaving successful unparasitized and parasitized nests was 8·4 and 15·4, respectively (24 Qiu-Xiang Deng, Hai-Tao Wang, Di Yao, Xing-Yang Wang, Ming-Ju E, Tuo Wang and Wei Gao (2011). Conspecific brood parasitism and nesting biology of Mandarin Ducks (Aix galericulata) in northeastern China. Wilson J. Orn.. 123(3): 479–485. Close ). Data on fledging success in wild lacking, but egg predators include American mink (Mustela vison), raccoon dogs (Nyctereutes procyonoides) and martens (Martes spp.), but no information concerning their effects; in captivity especially prone to avian tuberculosis, like A. sponsa, but relatively immune to aspergillosis and candidiasis (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Predators of adults include Siberian weasel (Mustela sibirica), Northern Goshawk (Accipiter gentilis) and Tawny Fish-owl (Ketupa flavipes) in native range (6 Sun, Y.-H., Bridgman, C.L., Wu, H.-L., Lee, C.-F., Liu, M., Chiang, P.-J. and Chen, C.-C. (2011). Sex ratio and survival of Mandarin Ducks in the Tachia River of central Taiwan. Waterbirds. 34(4): 509–513. Close ), and largemouth bass (Micropterus salmoides) in California (18 Lever, C. (2005). Naturalised Birds of the World. T. & A.D. Poyser, London, UK. Close ). Sexual maturity at one year (both sexes, in captivity). Adult annual survival studied on Taiwan, where rates of 74–80% for males and 44–50% for females recorded (with most of the latter lost during the physiologically demanding breeding period and the disparity apparently producing a heavily skewed sex bias towards males) (6 Sun, Y.-H., Bridgman, C.L., Wu, H.-L., Lee, C.-F., Liu, M., Chiang, P.-J. and Chen, C.-C. (2011). Sex ratio and survival of Mandarin Ducks in the Tachia River of central Taiwan. Waterbirds. 34(4): 509–513. Close , 8 Sun, Y.-S., Chiu, M.-C., Li, C.-F., Liu, M., Wu, H.-J. and Chiang, P.-J. (2014). The seasonal home range and movements of Mandarin Ducks Aix galericulata on tributaries of the Tachia River, central Taiwan. Forktail. 30: 41–44. Close ); similarly, in an introduced population in Germany annual survival was 65% in first-year males, 66% in adult males, 47% first-year females and 57% for adult females, these differences being fully explained by sex differences in survival; female mortality but not male mortality peaked during the breeding season (29 Bellebaum, J. and Mädlow, W. (2015). Survival explains sex ratio in an introduced Mandarin Duck Aix galericulata population. Ardea. 103(1): 183–187. Close ). Longevity records, oldest bird in captivity was 15 years old, while a free-flying bird in England was 11 years old (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Not globally threatened (Least Concern). At present, majority of Asian population, which was estimated at just 6100–6600 pairs in mid 1980s, occurs in Japan, with recent (early 2000s) population estimates of 20,000 in China, 5000 in Korea and 40,000 in Japan based almost entirely on winter data (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). In winter 1990 census, 13,361 birds counted in Japan , and 2332 in partial count in China (where overall wintering population is thought to 3000–4000 birds, with most on middle and lower reaches of Changjiang R, L Taihu and L Dongting) (30 Zhengjie Zhao (1998). Current status of Mandarin Duck in China and its distribution. P. 464 in:. Close ). Only minimally significant available figures on continental population are: 100 individuals counted during autumn/winter 1986 censuses in Taesong’dong and Panmucnch’om Marshes, South Korea, but up to 2550 were on Cheju I in Jan–Mar 1999 (31 Oh, H.-S. and Chae, H.-Y. (1999). Wintering flock of the Mandarin Duck (Aix galericulata) in Cheju Island, Republic of Korea. Jap. J. Orn.. 48(2): 161–163. Close ); in early 2004, some 718 were counted at sites in Jiangxi (32 Barter, M., L. Cao, L. Chen, and G. Lei (2005). Results of a survey for waterbirds in the lower Yangtze floodplain, China, in January–February 2004. Forktail 21:1–7. Close ) with c. 1000 in Wuyuan (NE Jiangxi) subsequently (33 He, F.-Q., Lin, J.-S., Wang, Y.-Y., Wang, G.-F., Hong, Y.-H., Zheng, P.-J., Wen, C., Lin, Z. and Shi, Q.-H. (2014). Bird records from Wuyuan, NE Jiangxi of SE China. Chinese J. Zool.. 49(2): 170–184. Close ), and flocks of 40–50 occur in early spring in Changbai Shan Nature Reserve, one of the breeding areas in NE China, where species nests mainly on upper reaches and tributaries of the Songhua, Yalu, Mundanjiang and Tumen rivers, being especially common on the Toudaobai, Erdaobai, Gutong, Tan Wang and Nancha rivers in Changbai and Xiao Xinganling, with an estimated overall population of 1000–1500 pairs in 1990s (30 Zhengjie Zhao (1998). Current status of Mandarin Duck in China and its distribution. P. 464 in:. Close ). In NE China, declines specifically noted on Toudaobai R in Changbai Mts, where breeding density in 1977/78 averaged 1·8 birds/km, but had declined to 0·90 birds/km by 1994 (30 Zhengjie Zhao (1998). Current status of Mandarin Duck in China and its distribution. P. 464 in:. Close ). In Japan was very common resident but greatly declined due to overhunting, with recovery after protection in 1947; notable increase in wintering population in particular, but not known if this because of increased breeding population or continental visitors; now considered local and uncommon, with further moderate increase in numbers wintering noted during 1996 to 2009 (34 Kasahara, S. and Koyama, K. (2010). Population trends of common wintering waterfowl in Japan: participatory monitoring data from 1996 to 211106111069. Orn. Sci.. 9(1): 23–36. Close , 35 Kasahara, S. and Koyama, K. (2011). [Regional population trend of common wintering waterfowl in Japan, from 1996 to 286869]. Jap. J. Orn.. 60(1): 35–51. (In Japanese with English summary.). Close ). Long thought not to breed in Korea, but evidence is available from several regions of the peninsula, although there is no population estimate (5 Duckworth, J.W. and Moores, N. (2008). A re-evaluation of the pre-1948 Korean breeding avifauna: correcting a ‘founder effect’ in perceptions. Forktail 24: 25–47. Close ). Relatively small numbers (c. 300–500 birds) resident in C Taiwan (6 Sun, Y.-H., Bridgman, C.L., Wu, H.-L., Lee, C.-F., Liu, M., Chiang, P.-J. and Chen, C.-C. (2011). Sex ratio and survival of Mandarin Ducks in the Tachia River of central Taiwan. Waterbirds. 34(4): 509–513. Close ). In Far East of Russia, has vanished from deforested basin of L Khanka and valley of Ussuri R, where now restricted mainly to its major tributaries (Khor, Bikin and Iman rivers); in 1990s considered to be still common on lower and middle Bikin, including its larger lower tributaries, the Alchan, Ulitka, Kushnarikha and Zmeinaya, with c. 350–400 pairs on the Bikin and c. 300 pairs in Amurland in the 1980s, with no evidence of a decline in the first-named during the 1990s, but is now largely confined to protected areas in S Primorye (26 Mikhailov, K.E. and Shibnev, Y.B. (1998). The threatened and near-threatened birds of northern Ussuriland, south-east Russia, and the role of the Bikin River basin in their conservation. Bird Conservation International. 8(2): 141–171. Close ). British feral population of c. 7000 in 1988 significant; currently increasing in both numbers and range, but no up-to-date population estimate (36 Holling, M., and the Rare Breeding Birds Panel (2011). Non-native breeding birds in the United Kingdom in 2006, 2007 and 2008. British Birds 104(3):114–138. Close ). Much smaller feral but often increasing populations more or less established in Ireland (2–5 pairs in early 1990s), France (5–10 pairs early 1990s, growing to 27–36 pairs and 135–140 individuals in 2011) (37 Dubois, P.J. (2012). Les populations d’oiseaux allochtones en France en 27811 (2e enquête nationale) Ornithos. 19(4): 225–251. Close ), Belgium (first bred 1987, up to ten pairs subsequently, 80–95 pairs by late 1990s) (28 Kestenholz, M., Heer, L. and Keller, V. (2005). Etablierte Neozoen in der europäischen Vogelwelt – eine Übersicht. Orn. Beob.. 102: 153–180. Close ), Netherlands (c. 50–60 pairs in 1992–1994) (28 Kestenholz, M., Heer, L. and Keller, V. (2005). Etablierte Neozoen in der europäischen Vogelwelt – eine Übersicht. Orn. Beob.. 102: 153–180. Close ), Germany (> 50 pairs in Berlin, smaller numbers scattered elsewhere, increasing to 430–600 pairs in whole country by 2005–2009) (38 Gedeon, K., C. Grüneberg, A. Mitschke, C. Sudfeldt, W. Eikhorst, S. Fischer, M. Flade, S. Frick, I. Geiersberger, B. Koop, M. Kramer, T. Krüger, N. Roth, T. Ryslavy, S. Stübing, S. R. Sudmann, S. Steffens, F. Vökler, and K. Witt (2014). Atlas Deutscher Brutvogelarten [Atlas of German Breeding Birds]. Stiftung Vogelmonitoring Deutschland und Dachverband Deutscher Avifaunisten, Münster, Germany. Close ), Denmark (c. 10 pairs in late 1980s), Austria (< 10 pairs in 1993) (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ) and Switzerland (first bred 1958, 10–20 pairs and up to 200 birds in 1985–1997) (39 Kestenholz, M. (1997). Status der Mandarinente Aix galericulata in der Schweiz [Status of the Mandarin Duck Aix galericulata in Switzerland]. Orn. Beob.. 94(1): 53–63. Close , 28 Kestenholz, M., Heer, L. and Keller, V. (2005). Etablierte Neozoen in der europäischen Vogelwelt – eine Übersicht. Orn. Beob.. 102: 153–180. Close ); also bred in Norway in 1970/71 (2 Snow, D. W., and C. M. Perrins, Editors (1998). The Birds of the Western Palearctic. Concise Edition. Volume 1. Non-passerines. Oxford University Press, Oxford, UK. Close ). Population in California (USA) estimated at 550 birds in mid 1980s (18 Lever, C. (2005). Naturalised Birds of the World. T. & A.D. Poyser, London, UK. Close ). Decline in continental Asia related to habitat destruction (through expansion of mining, agriculture and other industry) and exportation from China in vast numbers until as late as 1975 (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).