SOME PHOTOGRAPHIC STUDIES OF THE PINK-FOOTED GOOSE Photographed by ARNOLD BENINGTON, NIALL RANKIN and G. K. YEATES (Plates 9-16) THE Pink-footed Goose (Anser brachyrhynchus) breeds in east Greenland {between 68 and 76 N.), Iceland and Spitsbergen and is generally held to be the westernmost form of the Bean Goose (Anser arvensis), of which there are several populations breeding in northern Scandinavia, Russia, Siberia, Novaya Zemlya and probably Franz Josef Land. Certainly it is very closely related to the Bean Geese, although sufficiently different in appearance, voice and habit to be easily distinguished from any of the races of A. arvensis under reasonable conditions in the field. Were it, by an extension of breeding range, to overlap any Bean Goose population, it is a matter of speculation whether the two would merge or remain distinct. The chances of its remaining distinct seem good enough to give it a reasonable claim to specific status. The distinctive features- of the Pink-foot are (1) its relatively small, dark brown head, contrasting markedly with the paler brown of the lower neck and breast and the blue grey back and shoulders; (2) the pink legs of adults (all populations of the Bean Goose, save possibly one, have orange legs); (3) its rather short pink and black bill. The extent of the pink colouring on the bill is rather variable. Occasionally the bill is wholly pink, but usually three-fifths or more is black, although no cases of wholly black bills have been reported. All the birds illustrated, being on the breeding-grounds, are in summer plumage which is rather browner and less contrasted than in winter. Birds in their first autumn are also duller and browner than older birds. The whitish feather edges which accentuate the pattern on the scapulars of old birds (shown in all the plates) are much less prominent in young ones and the juvenile feathers are narrower and round-ended instead of the flat square-ended feathers of the adult. This is particularly noticeable on the breast and under-parts. First autumn birds also usually have duller pink legs, sometimes grey-tinted, and at other times more or less orange. Older birds with orange legs occur rarely (with a frequency of 1 in 1,000, or rather less). From mid-winter young birds are not safely distinguishable from adults in the field. There are two almost independent populations of the Pink-foot. The birds breeding in Greenland and Iceland winter in Britain, while those from Spitsbergen visit Denmark, Germany, the Low Countries and France. The independence of the two groups has been demonstrated by large scale ringing by the Wildfowl Trust in Iceland (over 10,000 ringed) and Britain (over 6,800 caught) and the ringing of 500 in Spitsbergen in 1952 and 1954 by parties from Cambridge University and Sherborne School. The continental 172
VOL. XLIX] PINK-FOOTED GOOSE 173 population is of the order of 5,000 in most autumns, the British population eight to ten times larger. Recoveries and recaptures of ringed birds have shown that the British population can be divided into a number of smaller groups varying considerably in the extent to which they may mix, but none apparently isolated. In England most Pink-feet occur in the Humber and Wash areas and in Lancashire. There are only a few small regularly occurring groups elswhere in England and Wales, apart from those at the east end of the Solway Firth, where large numbers occur divided between Cumberland and Dumfries-shire. Other Scottish strongholds are in the south-east, Fife, Perth, Angus and Aberdeen, while the Moray region is visited rather less consistently by large numbers mainly in the late spring. Until recently the Pink-foot was scarcely known in Ireland, but in the last few years individuals and small parties have been reported from widely scattered localities, though their status is probably still that of vagrants. The nest-sites shown in the photographs are typical of those used in most breeding areas, though in a few, notably Thjorsarver in Central Iceland, sites much more accessible to foxes and men are occupied. All these sites are on dry well-drained parts of the tundra marshes, often, but not invariably, close to water. The essential criteria for a nest-site appear to be a reasonable view for the sitting goose and a look-out point for the gander within five yards of the nest. Sites are often used year after year. In Iceland egg-laying begins in the second week of May and, unless checked by cold weather, the majority of clutches are completed before the end of May. In Spitsbergen the first eggs are not laid until early June and laying is largely concentrated in the second week of June. The incubation-period is twenty-eight days, or a little less, and goslings can fly at about eight weeks. Thus in Iceland the first goslings fly quite early in August, while in Spitsbergen few can fly before September. Information on nesting in Greenland is less extensive, but it appears that the times of laying and fledging there resemble those in Spitsbergen. The Pink-foot can be described as colonial, although most groups of nests are small and their density is never comparable with those attained by many other species of geese. The Thjorsarver oasis, of forty-four square miles, is estimated to have contained about 2,300 nests in 1951 and probably rather more in 1953, when about 8,200 adults including unknown proportions of non-breeders and "failed breeders" were present in mid-july. This is much larger than any other known colony. No group of more than 200 nests has yet been found elsewhere, nor is one likely to be found in Spitsbergen or in other parts of Iceland. But the Greenland breeding-places may include some large colonies, for those so far discovered fall short of the probable total population. At least two British expeditions to those parts of the Greenland coast frequented by the Pink-foot are being made in 1956, so that fresh discoveries are likely. PETER SCOTT
PLATE 9 Niall Rankin NESTING HABITAT OF PINK-FOOTED GOOSE (Anscr arvensis brachyrhynchus) Krossargil, North-Central Iceland: June 1954 G. K. Yeates NESTING HABITAT OF PINK-FOOTED GOOSE (Anser arvensis brachyrhynchus) Gorge of the Skjalfandafljot at Hrafnabjdrg, North Iceland: June 1954 Krossargil is the gorge where the interior-nesting geese of Iceland were first authoritatively identified as Pink-feet, by W. M. Congreve and S. W. P. Freme in 1929. Here at Hrafnabjdrg, they nest in mid-cliff, on the pinnacles and on buttresses and promontories on top.
PLATE IO Niall Rankin NEST AND EGGS OF PINK-FOOTED GOOSE (Anser arvensis brachyrhynchus) Hrafnabjorg, North Iceland: June 1954 A typical promontory or buttress site, giving excellent defence against attack by foxes (see page 173). Niall NEST-SITE OF PINK-FOOTED GOOSE (Anser arvensis brachyrhynchus) Hrafnabjorg, North Iceland: June 1954 A site in mid-cliff, immediately below the figure in plate 9 (lower). Rankin
PLATE II PINK-FOOTED GOOSE (Anser arvensis brachyrhynchus) KrossaVgil, North-Central Iceland: June 1954 The gander on guard near the nest. These plates show clearly the short and rather delicate beak which is a feature of this species of goose (see page 172).
PLATE 12 G. K. Yeates PINK-FOOTED GEESE (Anser arvensis brachyrhynchus) Krossargil, North-Central Iceland: June 1954 Throughout the incubation period the gander remains at all times very close to the sitting goose, and normally stands, or sits, right beside her. The birds here have just alighted, and he is moving up to join her.
PLATE 13 PINK-FOOTED GEESE (Anser arvensis brachyrhynchus) Krossdrgil, North-Central Iceland: June 1954 The basalt and lava gorges of Central Iceland are almost bereft of vegetation. The geese use the same nestsites for many years, and, thanks to the droppings of the breeding birds, little oases of grass occur round the nests (see page 173). Niall Rankin
PLATE 14 PINK-FOOTED GEESE (Anser arvcnsis brachyrhynchu.s) Krossargil, North-Central Iceland: June 1954 Both birds have detected the approach of danger, and are alert. is in fact standing on tip-toe. G. K. Yeates The gander
PLATE 15 Niall Rankin PINK-FOOTED GEESE (Anser arvensis brachyrhynchus) Krossargil, North-Central Iceland: June 1954 This shows clearly the citadel of the nest-site, with only one side to protect against possible attack from foxes. On all sides except the narrow approach is a sheer drop of 100 feet. The slopes of the hill behind are a barren scree.
PLATE 16.Arnold Benington PINK-FOOTED GEESE (Anser arvensis brachyrhynchus) Hrafnabjorg, North Iceland: June 1955 The gander on guard by the sitting goose. It will be observed that he has on his right leg a ring, almost certainly put on by the Wildfowl Trust either in Iceland or in Britain (see page 172).