Baikal Teal: new to Britain and Ireland D. I. M. Wallace After 26 and more years of debate, a Siberian duck is finally allowed aboard ... he long-established practice of adoring captive, imported wildfowl Tholds a permanent veil across the occurrence of extralimital species; and no duck has ever struggled harder to become accepted as a wild British bird than the Baikal Teal Anasformosa. In The Handbook, it featured only in a footnote and was treated as a frequent escape, along with the Wood Duck Aix sponsa and the Mandarin A. galericulata. Such an attitude was mirrored in ten other European countries from Finland and Sweden in the north to Italy and Malta in the south, although no less than five were obtained in the Saone Valley, France, in November 1836, before any known introduction to Europe (Cramp & Simmons 1977). One British record, of a duck (or immature) on Fair Isle, Shetland, in late September 1954, was clearly associated with an influx of other Siberian species; and the long persistence of its observers, particularly the late Kenneth Williamson, in arguing its case was clearly a factor in the inclusion of the Baikal Teal in the new category D of the British list (BOU 1971). There, six recent records were displayed for Britain and Ireland, all dated since 1927 and in late autumn and winter. They were a tantalising lot and might have remained so but for the arrival and long stay of an adult drake at Caerlaverock, Dumfries & Galloway, from mid February to early April 1973 (Brit. Birds 73: 530). The close observations made on this bird clearly demonstrated its wildness—it preferred goose and swan droppings to subsi• dised corn!—and, once again, the species went the rounds of review com• mittees. In 1980, after due deliberation (including a survey of all known European records), the BOU Records Committee accepted not only that wild vagrants could reach Britain, but also that both the 1954 Fair Isle and the Caerlaverock birds were such, so, eventually, following the opinions of the Wildfowl Trust and the late Dr J. M. Harrison (Harrison 1958). The rest of this paper tells the tale of the first individual and adds some general information on the species.

[Bril. Birds 74: 321-326, August 1981] 321 322 Baikal Teal: new to Britain and Ireland

Fig. 1. Baikal Teals Anas Jormosa. Lower left, head of duck, showing fully developed throat bridle (shown by 15% of individuals); upper left, juvenile; right, adult drake in breeding plumage (£>. I. M. Wallace)

Discovery and suspicion The birdwatchers present on Fair Isle in the third and fourth weeks of September 1954 enjoyed some classic drift weather and some (then) aston• ishing Siberian vagrants. The first of these was Britain's original Citrine Wagtail Motacilla citreola (Brit. Birds 48: 26-29) and most of the observatory's work from 20th to 23rd was devoted to its identification. On 24th, wide searches of the isle resumed, and that night the log listed three duck (or immature) Teal Anas crecca seen at Hestigeo by the late W. J. C. Conn, my late father W. J. Wallace and myself. On 25th, we flushed the same birds from a small pool near the geo and enjoyed excellent flight views at about 20m. The leading bird looked odd, being 'slightly larger' and showing 'a Wigeon-like pattern on the underbody' and 'a distinctly lighter white line above the speculum'. At the time, we were all junior students of migration and identification and had never heard of the Baikal Teal. Thus, our mention of an 'odd teal' drew little attention from our seniors, whose talk was still largely of the magic wagtail and other passerines, and we let the matter rest. It was not, however, ended.

Rediscovery, identification and ageing No sooner had we sailed away on 30th September than the 'three teal' at Hestigeo were rediscovered by H. A. Craw, W. Craw, Dr W. J. Eggeling, I.J. Ferguson-Lees and Kenneth Williamson. As we had on the 25th, they Baikal Teal: new to Britain and Ireland 323 immediately spotted the odd and wilder bird in the trio. Its larger size in flight again aroused suspicions and the greater extent of white above the speculum soon had them following the trio around the coast. Poor light prevented full observations on 30th, but an afternoon watch on 1st October allowed a close comparison of the odd bird with the two certain Teals (settled on the sea) and the following description (condensed from Williamson 1954) was obtained: 'obviously a female "teal" but bigger and brighter in plumage than the others . . . decidedly broader in the beam . . . had a bigger head, with a high forehead and very fine (apparently greyish) bill—the whole presenting a marked retrousee effect in profile . . . top of the head and nape warm brown, richer than in the Common Teal . . . feathers of mantle and scapulars appeared longer and had the outer webs edged with buff, these forming a pattern of "V" markings on the back . . . breast brown, mottled darker, and the belly white, and when the bird rose up in the water to wing-flap . . . there was a distinct line of demarcation between the two . . . flanks more heavily marked than in Common Teal, this being due to close dark brown blotching. . . tail blackish-brown, darker than the mantle, and . . . undertail-coverts . . . white. The closed wing showed a green speculum bounded on the inside by a narrow white line, and when the bird was flying this white was more extensive than in the Common Teal. When the bird swam towards us the face showed two conspicuous white marks on the lores; the sides of the head were greyish-white, and there was a narrow dark line through the eye.' The bird's character and appearance were discussed on the telephone with Hugh Boyd (then of the Wildfowl Trust) on both dates and all the senior observers considered the identification established and unques• tionable. It was not until December that the next issue of the observatory bulletin appraised the original observers of the rich sequel to their puzzle; and, although a letter 'connecting' the events was immediately sent to Williamson, no revised account was then published nor fully considered until the BOU Records Committee review of 1979. Even then, the bird's definition was not quite complete, for it now falls to me to make one small correction to the original account. As will be seen in the following section on field characters, adult duck Baikal Teal show rufous upper borders to their specula. The Fair Isle bird had a noticeably white one and so must have been in juvenile plumage.

Associated occurrences of other Eurasian vagrants Although the account of the Baikal Teal properly noted the possibility of its being an escape from captivity, Williamson also commented that 'it seems doubtful if [the species] will ever present better credentials to British ornithology than in this case.' The bird was present on Fair Isle in a period of intermittent, cyclonic easterly winds that brought not only Britain's first Citrine Wagtail, but also the second from 1st to 5th October, at least two Lesser Whitethroats Sylvia curruca of the Siberian race blythi on 21st and 22nd September, an Arctic Warbler Phylloscopus borealis and three Scarlet Rosefinches Carpodacus erythrinus on 20th. All these are common in areas of 324 Baikal Teal: new to Britain and Ireland Siberia adjacent to and overlapping the range of the Baikal Teal, as is the Siberian Thrush Zoothera sibirica, of which the first British individual appeared on the Isle of May, Fife, on 2nd October 1954 (Brit. Birds 48: 21-25). The occurrence of the last is particularly telling, since its trans- Eurasian vagrancy was the then longest recorded (and accepted) for any bird. No non-passerine Asian rarities were found in late September 1954, but four species of Siberian waders were obvious in south Shetland from 19th to 21st. (In passing, it may be noted that the autumn of 1954 was one of the very wide-flung dispersals in Holarctic birds, with two new Nearctic waders appearing ahead of the above birds and two rare wheatears Oenanthe coming after them. Omens of 1975 and 1976!)

181. Male Baikal Teal Anasformosa, USSR, April 1974 (Yuri Shibnev)

Field identification An adult drake Baikal Teal in breeding plumage is unmistakable; no other small to medium-sized Anas has such an intricately patterned, pale yellow and green-black head, long rufous-and-white-edged scapulars, narrow vertical lines fore and aft of dark grey flanks and an all-black undertail. At all other ages and in all other plumages, the Baikal Teal is subject to confusion with Teal, Blue-winged Teal A. discors and Garganey A. quer- quedula. This is particularly so with settled birds (hiding their wings) and separation must then be based on comparisons of size, strength of plumage pattern and, above all, facial pattern. The last varies in all duck, eclipse drake and immature Anas, but the following basic differences exist: TEAL Facial pattern usually indistinct in A. c. crecca, with little contrast between crown and rest of head and no pale or dark spots and lines obvious; more distinct in A. c. carolinensis, with crown and eye-stripe darker and thus more obvious than in A. c. crecca, but still lacking pale loral spots. Baikal Teal: new to Britain and Ireland 325

BLUE-WINGED TEAL Usually distinct, with crown darker than rest of head, fairly well-marked eye-stripe and noticeably pale, even almost white spot at base of upper mandible. GARGANEY Distinct, with whole head laterally lined by dark crown, eye-stripe and cheek bar, all con• trasting with pale supercilium and line under eye-stripe; last abuts base of upper mandible, but does not form isolated bold mark. BAIKAL TEAL Distinct, with very dark crown, dark eye-stripe, dark vertical line (or smudge) below eye and prominent, dark-outlined, almost-white spot at base of upper mandible, all visible against pale whitish-grey to grey-brown cheeks; supercilium narrow and incomplete, reddish-buff before eye, paler (lacking red tone) behind. About 15% of females show a very distinct set of dark 'bridles' on the sides of the otherwise pale throat (Harrison 1958).

In general terms, size and bulk range downwards from Baikal Teal, through Garganey and Blue-winged Teal to the Nearctic race and lastly the Palearctic race of the Teal. The most obvious size difference is in wing- length, with that of the Baikal Teal about 20% greater than that of the Teal. As with facial patterns, body-plumage marks vary (most in the Teal), but the feather centres of the back and flanks of the Blue-winged and Baikal Teal are noticeably dark. The back feathers of the latter are also visibly longer and more lanceolate than those of the other teals. In flight, differences in the upperwing patterns of teals show well. All the species discussed here exhibit green specula, but the pale blue and lavender-grey forewings respectively of the Blue-winged Teal and the Garganey are very distinctive, leaving the Baikal Teal and Teal to share similar grey-brown forewings and pale borders to their specula. Of the latter, the upper (or foremost) is the more obvious and is coloured rufous on adult Baikal Teal, pale buff (distally) to white (proximally) on adult Teal and virtually white on immatures of both species. It is formed by the visible tips of the greater coverts, which are wider in drakes than in ducks (M. A. Ogilvie in litt.). With field study of the Baikal Teal incomplete, it is impossible to analyse precisely the differences in the greater-covert bar (and it may be that its prominence on the Fair Isle bird was a function as much of size as of colour). So, it is important to recognise a further difference in flight appearance. This stems from the pattern of the under- wing, often very obvious on ducks. On the Teal, the dark grey lesser underwing-coverts are very broadly tipped white or whitish (often to nearly half the visible feather length) and they create on the leading edge a mottled dark, narrow band. In contrast, the same feathers on the Baikal Teal have no more than very narrow whitish tips (if any) and the leading edge is therefore considerably darker and broader. The difference is striking in skins and should show in the field. An excellent coloured plate of the Baikal Teal by Sir Peter Scott can be found in Hollom (1960, 1980), but no detailed plumage description exists in current identification texts. See also fig. 1, title drawing to this paper (for underwing of Baikal Teal) and Wallace & Ogilvie (1977). The drake Baikal Teal utters a distinctive, far-carrying clucking or chuckling note variously written 'klo-klo', 'wot-wot' and 'proop'. 326 Baikal Teal: new to Britain and Ireland Notes on the species The Baikal Teal is a rather secretive though often noisy duck of small, still and running freshwaters and thicketed riverine deltas in north-central and northeastern Siberia. Its range begins at the Yenisei and ends in Kam• chatka, spanning the northern taiga and the southern tundra edge between 70°N and about 55°N. Its population is highly migratory, withdrawing south to winter on marshes, rivers and ponds in Japan and eastern China. Spring passage is obvious in Korea, Manchuria and eastern Siberia, but the autumn return remains strangely undefined. Vagrants straggle farther east to Alaska, south to Hong Kong, and southwest to southwestern Siberia and northern India (Cramp & Simmons 1977). The Baikal Teal enters its breeding habitat from early May and departs from it in September. It rubs shoulders with Teal, Garganey and Falcated Teal A.Jalcata; no obvious dichotomy of habitat preference is known. Most nests are on or near water and often under willows Salix. Clutch size varies from six to nine, and eggs are laid in late June and early July. Ducklings hatch in about 25 days and are capable of flight after a further 30 to 35. The most recent analysis of the physiology and behaviour of the Baikal Teal (Johnsgard 1965) indicates that it is a close relative of the Teal, with similar plumage sequence, tracheal shape and displays.

Acknowledgments Robert Hudson and M.J. Rogers provided references to the Fair Isle and other records. M. A. Ogilvie added much more information on plumage characters and breeding behaviour. Summary An immature Baikal Teal Anas formosa present at Fair Isle, Shetland, from at least 25th September to 1st October 1954 is now considered the first certain wild vagrant of that species to have reached Britain. An account of the bird and its likely fellow-travellers is given, together with brief notes on field characters, range, migrations and breeding biology. References BRITISH ORNITHOLOGISTS' UNION. 1971. The Status of Birds in Britain and Ireland. London. CRAMP, S., & SIMMONS, K. E. L. (eds.) 1977. The Birds of the Western Palearctic. vol. I. Oxford. JOHNSGARD, P. A. 1965. The Handbook of Waterfowl Behaviour. New York. HARRISON, J. M. 1958. The Baikal Teal in the British Isles: a new record and a note on the incidence of the 'bridled' face pattern. Bull. BOC 78: 105-107. HOLLOM, P. A. D. 1960, revised 1980. The Popular Handbook oj Rarer British Birds. London. WALLACE, D. I. M., & OGILVIE, M. A. 1977. Distinguishing Blue-winged Teals and Cinnamon Teals. Brit. Birds 70: 290-294. WILLIAMSON, K. 1954. A Baikal Teal at Fair Isle, and other notes. Bull. Fair Isle Bird Obs. 2(5): 194-195. D.I. M. Wallace, 68Selby Road, Holme on Spalding Moor, York Y04 4EU