Habitat and Ecology
Behaviour This species is fully migratory, the main routes of migration being along Arctic coastlines7. It arrives on the breeding grounds in early-June3, 5 where it may breed in small, loose colonies1, 3, 7 or dispersed in single pairs7 (especially in the high Arctic where the habitat is unsuitable for large groups)2. There is a high degree of synchrony in egg laying and hatching4, with the adults moulting c.10 days after the young hatch (mid-July to mid-August5) during which they become flightless for c.21-30 days4, 5. Most individuals moult near the breeding grounds5 although immatures, unsuccessful breeders4 and some more southerly breeding groups6 may undertake pre-moult migrations4 and form large moulting concentrations well-away from nesting areas6. After the post-breeding moult flocks leave the breeding grounds in early-September with some arriving in wintering areas as early as mid-September, others making stopovers on route and arriving later3. It leaves its wintering quarters again from mid-March to mid-April3. During the non-breeding season the species remains gregarious, gathering in groups of only a few to several thousands of individuals7, although it is rarely found in very large flocks2. Habitat Breeding The species breeds in coastal Arctic tundra1 in or close to wet coastal meadows with abundant grassy vegetation2 and on tundra-covered flats with tidal streams (only just above the high tide line)4. In some parts of its range it shows a preference for nesting on small grassy islands2, 3, 4 in tundra lakes and rivers, especially if nesting Sabine's Gulls Xema sabini2, Snowy Owls Bubo scandiaca2, 6, Peregrine Falcons Falco peregrinus6 or large raptors are present to deter predators2. High Arctic nesters may also breed widely dispersed over icy tundra, well-away from water2. Non-breeding Outside of the breeding season the species becomes predominantly coastal, inhabiting estuaries1, 2, tidal mudlflats2, 3, sandy shores1, coastal saltmarshes2 (especially in the spring)5 and shallow muddy bays2. In recent years the species has taken to grazing on coastal cultivated grasslands3, 5 and winter cereal fields5, but rarely occurs on freshwater wetlands except on passage3. Diet The species is mainly herbivorous1 although it may take animal matter (e.g. fish eggs, worms, snails and amphipods)4. Breeding In its breeding habitat the diet of the species consists of mosses, lichens, aquatic plants1, sedges, tundra grass Dupontia spp., arrowgrass Triglochin spp. and saltmarsh grass Puccinellia spp. (Alaska)2, although the young may also take insects and aquatic invertebrates4. Non-breeding Outside of the breeding season the species predominantly takes marine microscopic and macroscopic algae1 (e.g. seaweeds, Ulva spp.2) and other aquatic plants linked with saline or brackish waters1 in the intertidal zone (e.g. especially eelgrass Zostera spp.2, 3, as well as Ruppia maritima, Spartina alterniflora, Salicornia spp., and arrowgrass Triglochin spp.)2. Breeding site The nest is a shallow depression1, 6 on the ground1. Although the species often nests close to water1 typically within a few hundred metres of the tideline7, high Arctic nesters may breed on icy tundra well away from water2 (some nearly up to 10 km inland)7 often near boulders where the snow clears first2. Management information An investigation carried out in one of the species's wintering areas (UK) found that it was most likely to forage on dry, improved grasslands that had high abundances of the grass Lolium perenne, were between 5 and 6 ha in area, and were at a distance of up to 1.5 km inland or 4-5 km along the coast from coastal roosting sites11. The species was found to show a preference for grasslands with short, dense swards c.5 cm in height, a characteristic that can be gained through summer management plans involving either mechanical cutting, livestock (sheep or cattle) grazing regimes, or cutting and then grazing (although over longer periods of time the selective grazing of sheep rather than cattle, and frequent rather than infrequent cutting may be more likely to enhance tillering and produce the short, dense sward favoured by this species)11. Fertilising the grassland with nitrogen in the autumn at a rate of 50 kg N ha1 was found to increase the overall species use of the habitat by 21 % compared with unfertilised areas11, and fertilising at a rate of 75 kg N ha1 was found to increase the overall species use of the habitat by 9-29 % and to remove any preference the geese showed for short sward heights (between 5 and 11 cm)11. In other fertilising experiments grazing intensity of the species was found to increase linearly with increasing levels of fertiliser (from 0 kg N ha1 to 150 kg N ha1), although responses in grazing intensity at fertiliser levels lower than 50 kg N ha1 were found to be short-lived (c.2 months after fertiliser application)11.
Systems
- Terrestrial
- Freshwater
- Marine
