February target bird: Barnacle Goose
A goose of the high Arctic, it comes to Britain and Ireland for the winter, arriving at traditional wintering sites, where thousands can be seen. Four wild populations are found in the Western Palearctic: one in east Greenland, another in Svalbard, a third from Arctic Russia (especially Novaya Zemlya) and the Baltic and a recent colony in Gotland, Sweden. A small number of birds became established in Iceland in the 1990s. There are also many naturalised birds in parts of Britain. The world population is estimated as about 500,000 birds.
Svalbard birds leave their breeding grounds in late August and move to Bear Island, in the south of Svalbard, before flying to Britain. During the latter half of September into early October they arrive at their wintering grounds on the Solway Firth, occasionally stopping in Norway on the way. From mid-April they leave and make their way to western Norway before moving through to Svalbard from mid-May.
In the 1940s the Svalbard population stood at about 300 birds, now it has increased to 30,000. However, the geese breeding there have a new threat to their survival. Polar Bears which are stranded on land during the summer are turning to goose eggs as a food source. During the 2009-10 winter, only half the expected number of goslings was seen at the Solway Firth. Research last summer showed that bears were eating vast numbers of eggs, and on one island of 500 nests only 40 survived predation.
The Greenland birds winter in Britain and Ireland, leaving their breeding grounds from late August and flying first to Iceland. They gradually move through to Britain and Ireland and have all left Iceland by November. The British birds are mostly found on Islay in the Hebrides, and the Irish ones along the north-west in Co Mayo and Co Donegal. They leave again in mid-April, stopping in Iceland on their way, arriving back in Greenland from late May. An estimated 70,000 birds from Greenland fly to Scotland and Ireland for the winter, with at least 12,000 birds overwintering in Ireland. About 300 birds are also seen on the Dyfi estuary in Wales.
Occasional birds from Russia or the Baltic, which usually winter in The Netherlands, occur on the Solway, and also in East Anglia; severe weather may result influxes. The Baltic population numbers about 130,000 birds, and the Gotland population is about 8,000.
In England, there are many hundreds of naturalised birds which have escaped from wildfowl collections and can be seen in places like the Humber Estuary, Minsmere RSPB and the Severn Estuary. While occasional wild Barnacle Geese may occur in Wales outside of the Dyfi population, it is difficult to separate these from introduced birds unless they are ringed.
Many Barnacle Geese breed on islands and mountain cliffs to avoid ground predators like Arctic Fox. Skuas and Glaucous Gulls will also take eggs and young. At cliff nest sites the chicks have to jump from the nest and may injure themselves as they fall onto the ground far below.
At some of their winter quarters, the geese may come into conflict with farmers and crofters, their grazing causing damage to grass crops. Barnacle Goose is protected by the Wildlife and Countryside Act, but licences can be granted to allow limited shooting where agricultural damage is caused, and only where scaring techniques do not work. In most cases payments are made to farmers to compensate for any damage.
The name Barnacle Goose comes from the belief that the bird 'hatched' from a barnacle shell growing on driftwood, which goes back at least as far as the 12th century. This belief led to the bird being accepted as a suitable food to be eaten on fast days when meat was forbidden.
How to see
The best way to see Barnacle Geese is in their spectacular winter flocks, by visiting reserves in their main wintering areas. Wild birds can be seen outside of these, wandering to nearby sites, but in many other places sightings cannot be readily separated from naturalised birds.
As the winter flocks may move around, it is best to watch from a dedicated hide or from a vantage point along a public right of way. When watching geese, always make sure not to disturb them, especially during severe winter weather.
Where to see
The sites below support traditional wintering populations, but as geese may wander they can also be seen at other locations nearby. No sites for naturalised birds have been included.
• Northumberland: Holy Island (NU 096397)
• Cumbria: Rockcliffe Marsh (NY 350622) and Campfield Marsh RSPB (NY 197615)
• Argyll: Loch Gruinart RSPB (NR 275672)
• Dumfries and Galloway: Caerlaverock WWT (NY 018653) and Mersehead RSPB (NX 928566)
• Argyll: Tiree (NL 960450)
• Outer Hebrides: Balranald RSPB (NF 706707)
• Orkney: Hoy RSPB (HY 222034)
• Powys: Ynys-hir RSPB (SN 682961)
• Co Mayo: Termoncarragh (F 654358)
• Co Sligo: Lissadell (G 639438)
• Co Donegal: Trawbreaga Bay (C 416504)