Common Shelduck Tadorna tadorna Scientific name definitions

58–67 cm (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 ); male 830–1500 g, female 562–1250 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 110–133 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 ). Unmistakable ; appears black and white at distance. Upperwing characteristic in flight with white on coverts , dark primaries and iridescent green secondaries  as in all Tadorna species. Bare parts: bright waxy red bill  with large basal knob  in spring, pink legs and feet, and brown eyes. Female slightly smaller with less prominent knob on bill, narrower breastband, blackish belly band, paler vent and usually some white between bill and eye; in non-breeding plumage is much like eclipse male, but remains paler, with browner head and sometimes has all-white underparts. Juvenile  , which superficially resembles young Alopochen aegyptiaca, has largely white underparts and grey or dull black dorsal parts, lacks chestnut breastband, and has white cheeks  and throat ; bare parts are entirely pinkish grey.

• Ruddy x Common Shelduck (hybrid) Tadorna ferruginea x tadorna
• Common Shelduck x Wood Duck (hybrid) Tadorna tadorna x Aix sponsa

Coastal NW Europe and scattered Mediterranean sites E through C Asia to NE China, and S to Iran and Afghanistan. In winter reaches N of Africa, Iraq, Pakistan, N India, Bangladesh and S China.

Favours coastal mudflats and estuaries, generally occurring in salt or brackish water, particularly in Europe, but often intentionally seeking fresh water, as well to drink. In Asia, prefers riverine environments, as well as marshes and lakes, in semi-desert and steppe areas (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 ). Recorded to 2400 m in Bhutan (3 Spierenburg, P. (2005). Birds in Bhutan: Status and Distribution. Oriental Bird Club, Bedford, UK. Close ).

Most northern and inland populations move southwards to winter at lower latitudes, thus many Asian birds move to Caspian basin, and small numbers move as far as N Africa, Iraq (with increasing numbers wintering in Arabia in recent years) (4 Meadows, B. S. (2012). The status of shelducks in the Eastern Province, Saudi Arabia. Phoenix 28:16-17. Close ), Pakistan, N India (S to Orissa and N Maharashtra (5 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ), and where recorded as late as third week of Apr) (6 Singh, A. P. (2000). Birds of lower Garhwal Himalayas: Dehra Dun valley and neighbouring hills. Forktail 16:101–123. Close ), Bhutan (7 Bishop, K.D. (1999). Preliminary notes on some birds in Bhutan. Forktail. 15: 87–91. Close ), Bangladesh, SE China (Oct–Apr), SW Korea, S Japan (especially Kyushu) and exceptionally Taiwan  (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 , 8 Brazil, M. (2009). Field Guide to the Birds of East Asia: Eastern China, Taiwan, Korea, Japan and Eastern Russia. Christopher Helm, London, UK. Close ); vagrant to Myanmar, Indochina (Laos and Vietnam), NW & C Thailand (9 Robson, C. (2000). A Field Guide to the Birds of South-east Asia. New Holland, London, UK. Close ) and perhaps even Borneo (Sabah) (10 Mann, C. F. (2008). The Birds of Borneo: An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union, and British Ornithologists’ Club, Peterborough. Close ). SE European breeding population merely flock in winter, though may move if weather is especially harsh (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 ). Generally considered only accidental visitor to Iceland (though has bred), Slovakia, Libya (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 ), Madeira (Nov 1932) (11 Clarke, T. (2006). Birds of the Atlantic Islands. Christopher Helm, London, UK. Close ) and Canary Is (six records between 1984 and 2004) (12 de Juana, E. and el Comité de Rarezas de la Sociedad Española de Ornitología (2001). Observaciones de aves raras en España, año 1999. Ardeola. 48(1): 117–136. Close , 11 Clarke, T. (2006). Birds of the Atlantic Islands. Christopher Helm, London, UK. Close ); in recent years, has wandered S to W Africa, with records in Mauritania and Senegal in 1973, then Niger (since 1982), Ghana (Jan 1986, Feb 2005) (13 Dowsett-Lemaire, F., and R. J. Dowsett (2014). The Birds of Ghana: An Atlas and Handbook. Tauraco Press, Liège, Belgium. Close ), Mali (since 1993) and Guinea (in 2006), and a total of 28 observations, all between mid Oct and late Feb, involving some 187 birds (14 Girard, O. (2009). Le Tadorne de Belon Tadorna tadorna en Afrique de l’Ouest. Bull. African Bird Club. 16(2): 180–183. Close ). Vagrant to S Russian Far East (8 Brazil, M. (2009). Field Guide to the Birds of East Asia: Eastern China, Taiwan, Korea, Japan and Eastern Russia. Christopher Helm, London, UK. Close ) and Philippines (15 Robson, C. (2013). From the field. BirdingASIA. 19: 123–128. Close ). Even within mainly sedentary populations (e.g. those of Britain and North Sea coasts), some spectacular gatherings at moulting sites, in some cases requiring extensive flights (see Family Text); thus, up to 100,000 gather at Heligoland Bight, on NW German coast, between Jun and Oct, with much smaller numbers gathering on several British estuaries, e.g. Bridgwater Bay, SW England (2000–4000 birds) (16 Fox, A.D. and Salmon, D.G. (1994). Breeding and moulting shelduck (Tadorna tadorna) of the Severn Estuary. Biological Journal of the Linnean Society. 51(1-2): 237-245. Close ), and on Rhine estuary, in the Netherlands (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 ). Two records from North America—Newfoundland (Nov 2009) and Massachusetts (Dec 2009)—are not accepted (17 Howell, S. N. G., I. Lewington, and W. Russell (2014). Rare Birds of North America. Princeton University Press, Princeton, NJ, USA. Close ).

Mostly aquatic invertebrates (molluscs, insects, crustaceans), with predilection for saltwater snail (Hydrobia ulvae), especially in NW Europe; also some small fish and spawn, worms and plant materials (algae, seeds and grain) (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 ). Observed predating eggs of Common Coot (Fulica atra) (18 Edwards, R. (2009). Common Shelduck predating eggs of Common Coot. British Birds. 102(11): 634. Close ). In S Europe and Asia, small crustacea and insect larvae are especially favoured (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 ducklings are apparently especially partial to Nereis and Corophium; one incubating female contained 11,858 Hydrobia snails, while a bird in Russia had 63,880 chironomid larvae in the stomach contents (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 ). Forages by digging, scything or dabbling on exposed mud and by head dipping and upending in shallow water up to 40 cm deep (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 ); young will also dive for food, from first day of life, but this behaviour declines rapidly after c. 2 weeks, in females more swiftly more than males (19 Düttman, H. (1992). Ontogenetische Verhaltensänderungen bei der Brandente (Tadorna tadorna): Schlafen, Tauchen, Nahrungserwerb. Journal of Ornithology. 133: S365-380. Close ). Regularly feeds by night, in line with tidal rhythms, and may spend up to 12 hours per day feeding, at least in winter (20 Hötker, H. (1995). Aktivitätsrhythmus von Brandgänsen (Tadorna tadorna) und Watvögeln (Charadrii) an der Nordseeküste [Activity rhythms of Shelducks (Tadorna tadorna) and waders (Charadrii) on the North Sea coast]. Journal of Ornithology. 136(2): 105–126. 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 ).

Especially just before and during breeding season; vocalizations sexually dimorphic  from early age (21 Engländer, W. and Bergmann, H.-H. (1990). Geschlechtsspezifische Stimmentwicklung bei der Brandente (Tadorna tadorna). Journal of Ornithology. 131: S174-176. Close ), with male  uttering varied whistling notes, especially a soft, clear “whee-chew” that becomes urgent and frequent in presence of perceived danger, while female calls are typically louder and lower-pitched (audible over long distances), and possess a cackling quality, e.g. “gagagagaga...” or “ak-ak-ak-ak...”, at rate of c. 12 notes/second, usually given in flight; both sexes give loud hissing notes when threatened (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 ); ducklings give high-pitched peeping notes while on move or feeding, or soft trills in close contact (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 ).

Starts Apr/May, with older birds generally returning to breeding grounds first (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 ). Monogamous, with long-term pair-bonds, although pair members may migrate and moult apart (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 ). Single-brooded (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 or small groups, sometimes nesting as close as 1 m apart (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 ); nest made of grass, moss or bracken, lined with down, in cavities such as hollow trees (up to 8 m above ground) (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 ) or 1–3 m down rabbit (Oryctolagus cuniculus) or other burrows, but also under hay bales or in nestboxes, and sometimes within more or less open vegetation (perhaps especially on islands), up to 1 km from water (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 ); site is chosen by female, who also adds material to nests in open sites (no material is usually added to burrow nests) (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 ). Usually 8–10 creamy white eggs (3–18 (22 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey: The Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close ), with some intra-specific parastism recorded) (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 ), laid at 24-hour intervals, size 61–71 mm × 43–50 mm, mass 65·5–92·5 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 c. 28–31 days (23 Harrison, C. J. O., and P. Castell (2002). Bird Nests, Eggs and Nestlings of Britain and Europe with North Africa and the Middle East. Second revised edition. HarperCollins, London, UK. Close ), by female alone guarded by male (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 hatch synchronously and have blackish down above and on thighs, white below, with green-grey legs and bill, weigh c. 50 g when one day 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 ); fledging c. 45–50 days in nursery areas that are regularly up to 3 km (exceptionally 30 km) (24 Leneveu, P. and Debout, G. (1994). Déplacements des Tadornes de Belon Tadorna tadorna de l’archipel de Chausey vers la baie du Mont-Saint-Michel en période de reproduction. Alauda. 62(2): 81-90. Close ) from nest-site, although parents may abandon young after 15–20 days to commence their own moult migration, whereupon young will form crèches of up to 100 ducklings guarded by one or more adults (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 ). One curious instance of apparent adoption of young T. tadorna by adult Eurasian Oystercatcher (Haematopus ostralegus) (25 López, F. and Morujo, S. (2012). Eurasian Oystercatcher feeding Common Shelduck chick. Dutch Birding. 34(5): 313–314. Close ). Most duckling mortality due to poor weather and predation by crows, foxes, skuas (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 ), Great Black-backed (Larus marinus) and Herring Gulls (L. argentatus) (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 ); one bizarre record of an adult Aythya fuligula killing a young shelduck (26 Bloomfield, A. (2006). The killing of a young Shelduck by a Tufted Duck. British Birds. 99(3): 153. Close ), while adult shelducks sometimes successfully defend their chicks, exceptionally even killing the would-be predator (27 Moncrieff, J. (2013). Common Shelducks attacking and killing Arctic Skua. British Birds. 106(3): 165-166. Close ). In successful nests, up to 90% of eggs hatch, but colonial nesters have hatching success of just 25–50%, thus dispersed populations have higher breeding success; 13-year study at Ythan estuary, in NE Scotland, found that 35% of young fledged and each pair fledged on average one young/year (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 ). Sexual maturity at two (female) or 4–5 years (male). Mean adult annual mortality 20% in one study, with mean life expectancy of 4·5 years and oldest ringed bird was c. 14·5 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). Widespread and fairly abundant, especially in W Palearctic , where numbers have increased and range has expanded during last four decades (e.g. first bred in Latvia in 1973, Lithuania in early 1980s (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 ), Switzerland in 1998–1999 (28 Knaus, P. and Balzari, C.A. (1999). Seltene Vogelarten und ungewöhnliche Vogelbeobachtungen in der Schweiz im Jahre 1998. [Rare and unusual bird observations in Switzerland in 1998]. Orn. Beob.. 96(3): 157-182. Close , 29 Volet, B. and Burkhardt, M. (1999). Übersicht über das Brutgeschehen und andere ornithologische Ereignisse 1997 und 1998 in der Schweiz [Rare and unusual records of breeding, migrating and wintering bird species, 1997 and 1998]. Orn. Beob.. 96: 255-271. Close , 30 Knaus, P. (2000). Die Brandgans Tadorna tadorna als neuer Brutvogel in der Schweiz [The Common Shelduck Tadorna tadorna, a new breeding bird species in Switzerland]. Orn. Beob.. 97(1): 7-20. Close , 31 Volet, B., and M. Burkhardt (2001). Übersicht über das Brutgeschehen und andere ornithologische Ereignisse 1999 und 2000 in der Schweiz [Rare and unusual records of breeding, migrating and wintering bird species in Switzerland, 1999 and 2000]. Ornithologische Beobachter 98:307–322. Close ), and has recently colonized Czech Republic) (32 Koleček, J., Reif, J., Šťastný, K. and Bejček, V. (2010). Changes in bird distribution in a Central European country between 1985–1989 and 291911–291913. Journal of Ornithology. 151(4): 923–932. Close ), perhaps in part due to decline in hunting and provision of nest-sites (either accidentally or planned) (33 Burgess, N. D., and G. J. M. Hirons (1992). Creation and management of artificial nesting sites for wetland birds. Journal of Environmental Management 34(4):285–295. 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 ), with inland nesting also becoming much more frequent in NW Europe during same period, for example in British Isles (34 Linton, E. and Fox, A.D. (1991). Inland breeding of Shelduck Tadorna tadorna in Britain. Bird Study. 38(2): 123-127. Close ); currently estimated to number c. 325,000 birds, with British population of c. 50,000 birds (10,600 pairs in 1988–1991), > 1500 pairs in France (and up to 35,000 in winters of 1987–1991, where the Somme Bay represents the most important site) (35 Gélinaud, G., Walmsley, J. and Mahéo, R. (1992). L’hivernage du Tadorne de Belon Tadorna tadorna en France. Alauda. 60(4): 235-238. Close , 36 Sueur, F., Desprez, M., Fagot, C. and Triplet, P. (2003). La Baie de Somme : un site sous-exploité par les oiseaux d’eau. Alauda. 71(1): 49-58. Close ), 6000–9000 pairs in the Netherlands, 10,000 pairs in Germany (in mid 1980s), 3000 pairs in Denmark, 2000–5000 pairs in Norway and 8000–12,000 pairs in Sweden (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 ). Major threat in this part of range is that of potential habitat change, such as plans for barrages on estuaries (37 West, A.D. and Caldow, R.W.G. (2006). The development and use of individuals-based models to predict the effects of habitat loss and disturbance on waders and waterfowl. Ibis. 148(1): 158–168. 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 ), but local declines have become evident due to conflict with shell fisheries (38 Atkinson, P.W., Maclean, I.M.D. and Clark, N.A. (2010). Impacts of shellfisheries and nutrient inputs on waterbird communities in the Wash, England. Journal of Applied Ecology. 47: 191–199. Close ). In Israel , has become quite common in winter in recent years, with 100–250 birds, and up to 2650 (1983), with first breeding documented in Jun 2016 (39 Ławicki, Ł., and A. B. van den Berg (2016) WP reports. Dutch Birding 38: 322–336. Close ), while > 13,000 were at Sabkhat al-Jabbul, NW Syria, in Feb 2004 (40 Serra, G., D. Murdoch, F. Turkelboom, F. Travert, Y. Mujawer, and D. A. Scott (2006). Sabkhat al-Jabbul, a threatened Ramsar wetland in Syria. Sandgrouse 28(2):127–141. Close ). Winters in large numbers in Iran, with 73,564 individuals recorded in 1991 census, whereas largest winter total in neighbouring Turkey is just 5390 birds (22 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey: The Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close ). Partial counts in winter 1991 yielded: 3137 in Bangladesh; 4027 in Pakistan; 12,241 in China; and 2333 in South Korea. Overall wintering populations estimated at 75,000 in Black Sea and Mediterranean region (where perhaps increasing) (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 ), 80,000 in W Asia, Caspian Sea and Middle East, 25,000–100,000 in C & S Asia, and 100,000–150,000 in E Asia (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 ). Large concentrations for moult (see Movements) make species potentially vulnerable to disease or natural disasters.