British Birds VOLUME 69 NUMBER IO OCTOBER I976

Distinguishing Great Snipe from Snipe D. I. M. Wallace Records of the Great Snipe Gallinago media are among the hardest to prove. The Rarities Committee has harped upon this theme and observers unfamiliar with the species and lacking The Handbook in their libraries are not given more than a few pointers to the possi­ bilities of its identification. This paper is therefore concerned with restating and clarifying the differences between it and the Snipe G. gallinago.

GROUND CHARACTERS The Great Snipe is the largest of the three species in western Europe, but it does not exceed the Snipe in all standard measurements. It is 5% to 10% longer- and broader-winged and about 10% longer- legged, but 10% shorter-billed and marginally shorter-tailed. It is bulkier, primarily because of its stouter bill, larger head, greater girth and broader wings. The second last difference gives it more of a ball shape on the ground. In the ideal circumstances of Snipe being present for comparison, these differences are obvious. Subtle but constant plumage differences are not restricted to the usually invisible tail markings and merit full discussion. General plumage pattern The Great Snipe is more barred than the Snipe, both above, where the individual feather patterns are very intricate, and below, where the markings are strong and numerous, extending in all plumages

[Brit. Birds, 6g: 377-383, October 1976] 377 378 Great Snipe and Snipe over a wider area. This increased complexity reduces the clarity of the back stripes and the prominence of the white belly, which is virtually invisible in immatures. In addition, its head and neck are heavily spotted with pale marks, giving a mealy appearance. Thus, it often shows a more uniform, less rufous and, because the back stripes are less evident, darker appearance. Head and bill The head pattern of the Great Snipe is subtly different from that of the Snipe, with less pronounced striping. This is most evident on the face, where typically the loral stripe is much thinner and the stripes or patches behind the eye and along the lower cheeks more diffuse. The effect is to give it a more open-faced appearance than the Snipe. The proportionately shorter, stouter bill combines with this feature to heighten the larger- and rounder-headed appearance. Underparts Swanberg (1965) rightly chose the strength of the markings on the underparts of the Great Snipe as one of two most important field characters. The presence of many dark spots and small chevrons on the chest, expanding into thick bars on the flanks and tibiae, is diagnostic of the species. These are set off by a buff to white ground colour in adults and by a pale brown to buff ground in immatures. The latter often appear dark underneath in the field and, on a good view, are thus instantly separable from the most heavily marked Snipe. In that species, the belly, lower flanks and tibiae almost always appear strikingly white. Wings Swanberg did not stress the importance of the pattern of the folded wing in the identification of the Great Snipe, though his photographs show it well. It has, however, become accepted as a much more useful character than the white tail corners, which are difficult to see. At all ages, this species shows strong barring or chequering on the coverts, made up of rather regular, transverse lines of white, black and brown (with the first colour most obvious), which form a clear panel on the mid wing. Also present is a marked 'speculum', almost completely black in adults and little-marked dark brown in immatures, bordered above by the white tips to the greater coverts and below by a wide, white trailing edge to the secondaries (fading on the inner primaries). The Snipe can show irregular white bars on the coverts, but usually the marks are in the form of scallops and spots. Importantly, it never shows any obvious speculum, because the secondaries are less densely coloured and more irregularly marked, and because both covert tips and trailing edges are duller. The latter are nevertheless still striking, particularly in flight. Great Snipe and Snipe 379

Fig. I. Immature snipes on ground. Left, Great Snipe Gallinago media: stouter bill, rounder head and build, and dusky underparts with complete barring. Right, Snipe G. gallinago: stronger stripes and white belly

Bare parts The bill of the Great Snipe can look paler and more uniform in tone than that of the Snipe, often showing a yellowish or greenish tinge at the base. The legs may also appear paler. Given the short odds that any snipe may fly at any moment, it is vital to concentrate on underparts, wing and face pattern first. Fig. i illustrates these aspects.

FLIGHT CHARACTERS Not every large, silent snipe that flies off slowly and silently is a Great Snipe. Large, tired Snipe of the nominate race and the vagrant American race G. g. delicata, which is shorter-billed and more barred below than our bird and may well cross the Atlantic more than its few records suggest, are a constant source of confusion. While many of the subtle marks discussed above will not be apparent, however, the Great Snipe can be identified in flight. Ground characters also visible in flight The greater bulk of the Great Snipe and its stronger barring on the underparts, restricted pale belly and, above all, the pale chequered mid-wing panel and speculum can all be evident. The last two fea­ tures, together with a dark carpal patch, are particularly striking on adults. In this respect, it is puzzling to find that King et al. (1975) effectively disputed the prominence of the speculum by giving the 38o Great Snipe and Snipe lack of a white trailing edge to the secondaries as a clear distinguish­ ing feature from the Snipe. I can find no justification for this state­ ment in other literature or skins, though it is a fact that the wing characters of the Great Snipe have not attracted the attention they deserve. Although they were acutely portrayed over 35 years ago by J. G. Harrison in The Handbook (plate 114), only a few incomplete references to them have appeared in the files of the Rarities Commit­ tee. This may simply be another example of the screening that has obscured other quite obvious field characters, such as the dark saddle of the immature White-winged Black Tern Chlidonias leucopterus 'discovered' as recently as 1959 (Williamson i960), but the chance remains that some Great Snipe have less patterned wings. I have seen one colour photograph of an adult with much duller wings than any of Swanberg's birds and, in a recent skin examina­ tion, I found a June adult with a folded wing appearance that I judged would have been identical with a well marked Snipe in the field, while several other specimens were noticeably duller than usual. Axillaries and underwings In the Great Snipe, these are as strongly barred as the underparts. Only in G. g. delicata and a few G. g. gallinago are such pronounced markings present. This is an important mark in the case of dark- tailed, immature Great Snipe, but it is difficult to observe with certainty. Tail Adult Great Snipe display brilliant white corners (almost the outer thirds) to their tails. Immatures that have not completed the first moult do not, and the restricted white tips to their outer tail feathers are similar to those of Snipe at any age. Swanberg (1965) chose the white tail corners as one of two most important field characters of adult Great Snipe, but the fact is that, except when braking just before landing, snipes rarely oblige by fanning their tails. It is not easy to observe this character in either species, but failure to see it does not necessarily prevent identification. As may now be apparent, there are other marks worth looking for. Flight action and silhouette There is complete unanimity about the heavier appearance and the slower, straighter, level flight of the Great Snipe. Its resemblance to that of a small Woodcock Scolopax rusticola bears repeating. Of nearly a hundred Great Snipe that I have flushed in Europe and West and East Africa, not one has ever given the impression of the frantic, terrified escape flight that so characterises the departure of a fit Snipe. I have, however, seen a few, probably tired, Snipe go off in a manner that suggested Great Snipe, and such birds must Great Snipe and Snipe 381 constantly be borne in mind. If faced with one, observers should concentrate on structure and plumage pattern. The broader wings of the Great Snipe and the shorter bill length are evident in a good view; bill carriage may also differ. Some Great Snipe appear to carry their bills much nearer to the horizontal than do Snipe: Swanberg (1965) estimated the angle of depression in the Great Snipe to be 15% to 20%. Seeing a large snipe slowly flying away, it is vital to concentrate on the wing pattern. If the bird comes round or lands, the pattern of the underparts and tail are the most important features to look for. Fig. 2 shows the flight appearance of both snipes and of the Woodcock.

Fig. 2. Woodcock Scolopax rusticola, and snipes in flight. Left, Woodcock with characteristic vermiculated plumage and lack of wing pattern. Centre, Great Snipe G. media with definite wing pattern (see text) and Woodcock-like set; note tail of immature resembles that of Snipe G. gallinago at all ages, but that of adult (inset below) has outer thirds virtually white. Right, Snipe, with obvious back stripes, indistinct wing pattern and (inset above) characteristic escape flight

HABITAT AND BEHAVIOUR In its breeding and wintering areas, the Great Snipe inhabits much drier ground than does the Snipe. Only in East Africa in a dry season have I seen it regularly enter open water. It does not shun marshes, however, and, since the Snipe frequently occurs in dry habitats, such as bracken and long grass, there is a wide overlap in habitat. The Great Snipe, however, has a marked liking for tussock grass and heather, in which it commonly roosts, sitting tight all day. It is essentially a nocturnal species in a normal sun cycle: in West Africa, Great Snipe flush only on direct disturbance. 38a Great Snipe and Snipe As just implied, many Great Snipe must escape notice by hidden immobility, and it is rare to see migrants moving about. When they do, their gait appears less free than that of Snipe: they tend to shuffle about, hunched on bent legs and taking food from the surface as well as probing for it below ground. H. Seebohm, quoted in The Handbook, saw them as 'very comical'; to my eyes they look 'a little stupid', in a way that the Snipe never does. Great Snipe have a reputation for solitariness, but they are in fact gregarious in the breeding season, with males attending communal display grounds, and they occur in scattered flocks in Africa in winter..

CALLS For a bird that makes all sorts of extraordinary noises in breeding display, the Great Snipe is exceptionally silent on migration and in winter. Of 27 records in the files of the Rarities Committee, 19 individuals always rose without calling. The other eight called at least once, the noise being described as a quiet, gruff or guttural croak, grunt or cough; the only transcription described this as a deep 'heert'. One individual additionally gave a low, deep, faint 'tswick', reminiscent of a quiet 'titipp' which I heard once from one flushed at dusk. Thus, 70% of the Great Snipe recorded in Britain during 1958-75 were silent when flushed (often repeatedly) and 30% uttered a croaking call quite unlike that of the Snipe (but some called only once, even though they were flushed on more than one occasion). It may be significant, however, that, on four occasions, special note was made of wing-noise as the bird rose: a feature not known to be a character of the species and, therefore, perhaps unrecorded in other instances. The voice of the Snipe is too well known to warrant a review here.

GREAT SNIPE IN BRITAIN AND IRELAND The British Ornithologists' Union (1971) described the Great Snipe as a scarce and decreasing visitor, wida older records mainly in autumn, but more recent ones in that season and in winter. During 1958-75, there were at least 35 records in Britain and Ireland. Most were in autumn on northern Scottish isles and down the eastern half of England, with a mean arrival date of 8th September clearly reflecting the late August to mid-September withdrawal from Scandinavian breeding grounds (Swanberg 1965). There is a hint of onward passage through Britain in four October records (mean date nth) in Scilly, but ten later occurrences from mid- November to February, with seven on or below the axis of the Severn and the Wash, suggest a small wintering population. As Sharrock and Sharrock (1976) have pointed out, however, at least 81 % have been seen on only a single date and there has been but one Great Snipe and Snipe 383 record of a long stay in the past 18 years (December-February 1962/63 in Buckinghamshire). Nevertheless, five widely scattered spring records hint at the withdrawal of these birds, rather than passage, since the lack of any recent late May or early June records is significant when the increasingly regular occurrences at that time of sympatric species, such as the Broad-billed Sandpiper Limicola falcinellus, are considered. It is by no means certain that there has been any real change in the status of Great Snipe in Britain and Ireland, however, since the pattern indicated above is present in the older records, even in such a landlocked county as Hertfordshire (Sage 1959). It is likely that changes in the shooting behaviour of collectors and wildfowlers have played as big a part in the Great Snipe's apparent decline as has the reduction of the European population (Voous i960) or the difficulty of field identification.

ACKNOWLEDGEMENTS I am grateful to the members of the Rarities Committee, particularly P.J. Grant, for comments on snipe identification and on an early draft of this paper, and to I. C. J. Galbraith for access to specimens in the British Museum (Natural History).

SUMMARY Previous criteria on the differentiation of the Great Snipe Gallinago media and Snipe G. gallinago are restated, along with the product of recent researches in field identification. The best indicators of the former species are its more striking wing pattern, which usually includes a marked speculum, its heavily barred underparts and its Woodcock-like flight. It usually rises silently, but sometimes utters a guttural croak when flushed. Essential references are The Handbook and Swanberg (1965); the latter contains a series of most informative photographs. The Great Snipe appears to have become scarcer in recent years, but there is no evidence of a real change in its occurrence pattern in Britain and Ireland.

REFERENCES BRITISH ORNITHOLOGISTS' UNION. 1971. The Status of Birds in Britain and Ireland. Oxford. KING, B. F., DICKINSON, E. C, and WOODCOCK, M. W. 1975. A Field Guide to the Birds of South-East Asia. London. SAGE, B. L. 1959. A History of the Birds of Hertfordshire. London. SHARROCK, J. T. R., and SHARROCK, E. M. 1976. Rare Birds in Britain and Ireland. Berkhamsted. SWANBERG, P. O. 1965. 'Studies of less familiar birds. 138. Great Snipe'. Brit. Birds, 58: 504-508. WILLIAMSON, K. i960. 'Juvenile and winter plumages of the marsh terns'. Brit. Birds, 53: 243-252. WITHERBY, H. F., JouRDAiN, F. C. R., TICEHURST, N. F-, and TUCKER, B. W. 1940. The Handbook of British Birds. Vol. IV. London. Voous, K. H. i960. Atlas of European Birds. London.

D. I. M. Wallace, 9 Woodhill Rise, Heads Lane, Hessle, Hull, North Humberside HUI3 OHZ