Regular wintering fowl joined by rarer Tundra bean geese
Waterfowl are prominent at this time of the year, when resident wintering duck and geese populations are increased by visitors from further north.
Wintering freshwater species of duck are usually recorded on lochs, especially those with nutrient-rich waters, but sheltered voes also provide a winter refuge for some visitors such as the fine male pintail which we watched swimming with a group of mallard at Boddam on 28th January.
Illuminated by the winter sunshine, its smart plumage was shown off to best advantage. About the size of a mallard, the male pintail is a slim, elegant long-necked duck with long central tail feathers.
A male in breeding plumage is unmistakeable, having a grey body, contrasting with a brown head and gleaming white breast and neck feathers which extend into a narrow stripe on the head. The undertail is cream and black.
The pintail is a scarce passage migrant, more frequently recorded in spring than in autumn. Sporadic arrivals occur in winter of one or two birds, probably as a result of cold weather movements.
Like the mallard, the pintail is a dabbling duck, upending to feed on aquatic insects and plants. The breeding distribution is circumpolar, with pintail having a more northerly range than most dabbling duck species. Pintails winter to the south of the breeding areas and winter arrivals in Shetland are probably from Iceland. There is a small breeding population in Britain with most of the Scottish population breeding in Orkney.
Also on the 28th there were two shelduck recorded at Spiggie and we observed one on the Loch of Hillwell.
There is a small Shetland breeding population of shelduck and these boldly patterned, large ducks start to arrive in late autumn/winter. After the breeding season, they probably join the majority of the Scottish population which migrate to the Heligoland Bight in north-west Germany to moult.
Also on Hillwell was a flock of 50 wigeon with 127 recorded on the Loch of Benston, South Nesting, on the 31st.
Since the 1970s a breeding population of greylag geese has become established in Shetland, and the immigrant wintering population has increased.
During the winter, other visiting species of geese may occur, such as the three European white-fronted geese at Spiggie and the Tundra bean goose at Sandwick. The European white-fronts were in the same field as a large flock of greylags but were grazing apart from them. Resembling a pink-foot, they have a distinctive white blaze at the base of the bill and black barring on the belly.
Five different races of white-fronts breed in Arctic and sub-Arctic regions. Most Scottish records occur between December and March, probably as a result of cold weather in their continental wintering grounds. Most sightings are of singles or small groups of two or three geese but large influxes occurred in 1984/85 and 1995/96 involving flocks of up to almost 50.
The bean goose is closely related to the pink-footed goose but is smaller, shorter-necked and shows more contrast between the dark neck and pale grey body and has orange legs. The Tundra race has a small orange patch on the dark bill. Like the white-fronts, the number arriving in Britain depends on the severity of the winter on the continent. The Tundra bean goose is a rare migrant from the tundra regions of Northern Europe and Siberia, wintering in Spain, France, Italy and the Balkans.
If the cold weather affecting much of Europe this week continues, it will be interesting to see what turns up next.
Joyce J M Garden
