Species

Justification
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls.
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Christidis, L.; Boles, W. E. 1994. The taxonomy and species of birds of Australia and its territories. Royal Australasian Ornithologists' Union, Melbourne.
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
Cramp, S.; Perrins, C. M. 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
SACC. 2006. A classification of the bird species of South America. Available at: http://www.museum.lsu.edu/~Remsen/SACCBaseline.html.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Stotz, D. F.; Fitzpatrick, J. W.; Parker, T. A.; Moskovits, D. K. 1996. Neotropical birds: ecology and conservation. University of Chicago Press, Chicago.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Population justification
The global population is estimated to number c.4,600,000-6,500,000 individuals (Wetlands International, 2006), while national population estimates include: < c.10,000 individuals on migration and > c.10,000 wintering individuals in China; > c.1,000 individuals on migration and > c.1,000 wintering individuals in Taiwan; > c.1,000 individuals on migration and c.50-1,000 wintering individuals in Korea; > c.1,000 individuals on migration and c.50-10,000 wintering individuals in Japan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Russia (Brazil 2009).

Trend justification
The overall population trend is decreasing, although some populations are stable or have unknown trends (Wetlands International 2006). This species has had stable population trends over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).

Ecology
Behaviour This species is a fully migratory circumpolar breeder with several sub-populations that employ a number of migration strategies, from short coastal flights to long, non-stop flights overland on a broad front (del Hoyo et al. 1996). The sub-population that breeds in north-east Greenland migrates through Iceland, Britain and western France to arrive in its West African wintering grounds (specifically Banc d'Arguin in Mauritania) from late-July, returning again between March and early-April (del Hoyo et al. 1996). European birds may gather in large congregations from the beginning of July in areas such as the Wadden Sea or the Wash to moult (del Hoyo et al. 1996), and some juveniles may remain in the non-breeding range all year (del Hoyo et al. 1996). The species breeds dispersed or aggregated in loose colonies, and travels in group sizes of up to 1,500 on passage, remaining in large groups (up to hundreds of thousands of birds) throughout the non-breeding season (Cramp and Simmons 1977, del Hoyo et al. 1996). The species is active both diurnally and nocturnally (Cramp and Simmons 1977, del Hoyo et al. 1996, Shepherd and Lank 2004). Habitat Breeding In the breeding season this species frequents moist boggy ground interspersed with surface water, such as tussock tundra and peat-hummock tundra in the arctic, as well as wet coastal grasslands, salt marshes and wet upland moorland (Cramp and Simmons 1977, del Hoyo et al. 1996). Non-breeding In the non-breeding season this species mainly prefer estuarine mudflats, but also frequent a wide variety of freshwater and brackish wetlands (Cramp and Simmons 1977, del Hoyo et al. 1996), both coastal and inland, including lagoons, muddy freshwater shores, tidal rivers, flooded fields, sewage farms, salt-works, sandy coasts (Cramp and Simmons 1977, del Hoyo et al. 1996), lakes and dams (Hockey et al. 2005). For roosting during high tides and at night this species prefers large fields of naturally fertilised short pasture or soil-based crops with few vertical structures that could be used by predators (Shepherd and Lank 2004). Diet Breeding This species is omnivorous during the breeding season, consuming mostly adult and larval insects (dipteran flies, beetles, caddisflies, wasps, sawflies and mayflies), and also spiders, mites, earthworms, snails, slugs and plant matter (usually seeds) (Cramp and Simmons 1977, del Hoyo et al. 1996). Non-breeding It is also omnivorous during the non-breeding season, consuming mostly polychaete worms and small gastropods, as well as insects (dipteran flies and beetles), crustaceans, bivalves, plant matter and occasionally small fish (Cramp and Simmons 1977, del Hoyo et al. 1996). Breeding site Its nest is a scrape or shallow depression in the ground, concealed in vegetation and sometimes in a tuft or tussock (and thus raised slightly off the ground) (Cramp and Simmons 1977, del Hoyo et al. 1996). Management information The provision of well-surfaced paths in breeding areas that recieve > 30 visitors a day has been shown to reduce the impact of human disturbance on this species' reproductive performance (Pearce-Higgins et al. 2007). It is also known to show increased hatching successes when ground predators have been excluded by erecting protective fences around nesting areas (Jackson 2001).

Threats
Breeding This species is significantly threatened by the loss of its breeding habitat though afforestation of moorland (del Hoyo et al. 1996, Lavers and Haines-Young 1997). It may also suffer from nest predation by introduced mammals (e.g. European hedgehog Erinaceus europeaus) on some islands (Jackson 2001). Non-breeding In the winter this species is restricted to a small number of estuaries, so it is vulnerable to any changes in this habitat for example through land reclamation (drainage) (del Hoyo et al. 1996), and the invasion of alien plant species (such as the grass Spartina anglica which has spread on British mudflats, resulting in the reduction in size of feeding areas available) (del Hoyo et al. 1996). The species is also threatened by disturbance on intertidal mudflats from construction work (UK) (Burton et al. 2002a) and foot-traffic on footpaths (Burton et al. 2002b). Important migratory stop-over habitats on the Baltic Sea coastline adjacent to the Kaliningrad region of Russia are threatened by petroleum pollution, wetland drainage for irrigation, peat-extraction, reedbed mowing and burning, and abandonment and changing land management practices leading to scrub and reed overgrowth (Grishanov 2006). The species is also susceptible to avian influenza (strain H5N1 in particular) and is therefore threatened by outbreaks of the virus (Melville and Shortridge 2006).

Related state of the world's birds case studies

• In the Arctic tundra, climate change will cause dramatic losses in waterbird breeding habitat

References
Cramp, S.; Simmons, K. E. L. 1977. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic, vol. I: ostriches to ducks. Oxford University Press, Oxford.

del Hoyo, J.; Elliott, A.; Sargatal, J. 1996. Handbook of the Birds of the World, vol. 3: Hoatzin to Auks. Lynx Edicions, Barcelona, Spain.

Shepherd, P. C. F.; Lank, T. B. 2004. Marine and agricultural habitat preferences of Dunlin wintering in British Columbia. Journal of Wildlife Management 68(1): 61-73.

Hockey, P. A. R.; Dean, W. R. J.; Ryan, P. G. 2005. Roberts birds of southern Africa. Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa.

Grishanov, D. 2006. Conservation problems of migratory waterfowl and shorebirds and their habitats in the Kaliningrad region of Russia. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 356. The Stationary Office, Edinburgh, UK.

Melville, D. S.; Shortridge, K. F. 2006. Migratory waterbirds and avian influenza in the East Asian-Australasian Flyway with particular reference to the 2003-2004 H5N1 outbreak. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 432-438. The Stationary Office, Edinburgh, UK.

Burton, N. H. K.; Rehfisch, M. M.; Clark, N. A. 2002. Impacts of Disturbance from Construction Work on the Densities and Feeding Behavior of Waterbirds using the Intertidal Mudflats of Cardiff Bay, UK. Environmental Management 30(6): 865-871.

Burton, N. H. K.; Armitage, M. J. S.; Musgrove, A. J.; Rehfisch, M. M. 2002. Impacts of Man-Made landscape Features on Numbers of Estuarine Waterbirds at Low Tide. Environmental Management 30(6): 857-864.

Jackson, D. B. 2001. Experimental Removal of Introduced Hedgehogs Improves Wader Nest Success in the Western Isles, Scotland. Journal of Applied Ecology 38(4): 802-812.

Lavers, C. P.; Haines-Young, R. H. 1997. Displacement of dunlin Calidris alpina schinzii by forestry in the flow country and an estimate of the value of moorland adjacent to plantations. Biological Conservation 79(1): 87-90.

Pearce-Higgins, J. W.; Finney, S. K.; Yalden, D. W.; Langston, R. H. W. 2007. Testing the effects of recreational disturbance on two upland breeding waders. Ibis 149: 45-55.

Further web sources of information
Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.

View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Butchart, S., Ekstrom, J., Jones, V., Malpas, L.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Calidris alpina. Downloaded from http://www.birdlife.org on 25/05/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/05/2013.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

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Additional resources for this species

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