| Habitat and Ecology: |
Behaviour This species is fully migratory1, travelling on a narrow front2 between separate breeding and wintering grounds1. It breeds from mid-May to late-June or early-July2 in territorial pairs3 which may form loose colonies1, 3 of not more than c.10 pairs5. After breeding the species undergoes a flightless moulting period in July and August that lasts for c.25 days4, during which it remains close to open water (such as the sea or early thawing lakes)2. Icelandic non-breeding flocks migrate to staging areas2, 3 in east Greenland to moult, whereas breeding birds from Svalbard, Greenland and Iceland remain near their breeding areas4. After moulting the species departs from its breeding and staging grounds2 from August to mid-September3, most arriving on the wintering grounds in October3. Outside of the breeding season the species remains highly gregarious3, generally forming large concentrations in the autumn (commonly up to 5,000 in the UK)5 and in winter3. These aggregations are usually loose however, with large roosting flocks dispersing into smaller foraging groups by day5. During the winter the species roosts on water by night and forages in nearly all hours of daylight2. Habitat Breeding The species breeds on rocky outcrops, crags, steep river gorges1, 2, cliffs, riverbanks and snow-free hummocks near areas of lush vegetation (Greenland)2 in open arctic tundra1, especially near seabird colonies2. Later in the summer the species forages chiefly on damp sedge-meadows, and while moulting and flightless it remains close to the sea or early-thawing lakes2. Non-breeding The species overwinters on extensive areas of saltmarsh2, 3 in estuaries1 and on flat agricultural land1 (e.g. improved or fertilised grasslands, stubble fields, pastures and newly sown cereal fields)2. In Scotland favoured winter daytime roosting sites include estuarine mudflats, lochs and reservoirs3. Diet The species is hebivorous1 and an opportunistic forager2. Breeding During the breeding season its diet consists of the leaves, stems, roots, berries and seed-heads of sedges, mosses, lichens1, Empetrum spp. and grasses2. Non-breeding In its wintering areas the species is more reliant on grass, grain, vegetables (e.g. carrots, sugar beet2) and potatoes grown on agricultural land1. Breeding site The nest is a low mound of vegetation1, 2 on cliffs, rocky outcrops or snow-free hummocks2 often near seabird colonies2. The species nests in territorial pairs3 which may from loose colonies1, 3 of not more than c.10 pairs, with neighbouring nests spaced as little as 5 m apart (usually more than 75 m apart)5. Management information An investigation carried out in one of the species's wintering areas (UK) found that it was most likely to forage on grasslands a minimum of 6 ha in area, managed by livestock grazing or mechanical cutting, with an optimum sward height of 13-20 cm (although the species was also found to use heavily grazed land down to a sward height to 1.5 cm), at a distance of less than 10 km away from roosting sites (the optimum distance was 2-5 km away)7. Fertilising the grassland with nitrogenous fertiliser (ammonium nitrate 34.5 % N) in early-March at a rate of 80 kg N ha1 was also found to double the grazing intensity of geese compared to unfertilised areas (although no further increases were found with higher rates of fertiliser application)7. Studies in the Vejlerne nature reserve, Denmark found that wind turbines placed in lines or small clusters cause less disturbance to the species than large clusters (small clusters may be placed in conjunction with existing physical elements such as roads, wind-breaks or buildings, and are therefore less likely to coincide with grasslands areas used for grazing by the species)8.
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