Justification of Red List Category
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). The population trend appears to be increasing therefore it is not believed 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.
The global population is estimated to number c.1,500,000-1,600,000 individuals (Wetlands International 2015). This roughly equates to 1,000,000-1,100,000 mature individuals. The European population is estimated at 48,200-76,000 pairs, which equates to 96,400-152,000 mature individuals (BirdLife International 2015). The population in Russia has been estimated at c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration (Brazil 2009).
The overall population trend is increasing, although some populations have unknown trends (Wetlands International 2015). The European population is estimated to be stable (BirdLife International 2015).
Behaviour This species is a full long-distance migrant that migrates overland on a broad front (or by utilising a great many routes) across much of the Western Palearctic (del Hoyo et al. 1996, Snow and Perrins 1998). It is also nomadic in parts of its wintering range (e.g. southern Africa), moving as habitats flood or are overgrown (Hockey et al. 2005). Autumn movements to wintering grounds occur between July and November; the return migration occurring mid-May to early-June, with breeding occurring between late-June and early-July (del Hoyo et al. 1996). Many immatures also remain in the wintering grounds all year round (del Hoyo et al. 1996). This species is gregarious outside of the breeding season and occurs in small groups in its winter range, often aggregating into larger flocks to roost at high tide or at night (Urban et al. 1986, Snow and Perrins 1998, Hockey et al. 2005). A typical migratory flock can be as large as 20-30 individuals (del Hoyo et al. 1996). Breeding pairs sometimes nest as close as 5 pairs/ha, but more often they are dispersed (around 10 pairs/km2) (del Hoyo et al. 1996).
Habitat Breeding During the breeding season this species inhabits low altitude tundra in the high Arctic (although it exceptionally occurs above 1,000 m in the west of its range) (del Hoyo et al. 1996, Snow and Perrins 1998). It shows a preference for dry ground among dwarf willows near swampy areas or saltmarshes, or areas where mosses and sedges are interspersed with hummocks covered by Empetrum (Johnsgard 1981, del Hoyo et al. 1996). It avoids areas where annual rainfall exceeds 250 mm (del Hoyo et al. 1996). Non-breeding On migration this species is found along the muddy edges of small inland lakes, reservoirs, sewage farms, riverbanks and seasonal pools, as well as on coastal mudflats and seashores (Johnsgard 1981, del Hoyo et al. 1996, Snow and Perrins 1998). In its winter range the species mainly inhabits coastal areas such as estuarine mudflats and sandflats, enclosed lagoons, tidal creeks and saltpans, but it also occurs at inland freshwater wetlands such as open pools in marshes, paddyfields, jheels (and other small bodies of water covered with vegetation), small dams, floodwater margins and sandbanks along rinvers (Urban et al. 1986, del Hoyo et al. 1996, Hockey et al. 2005).
Diet The diet of this species consists chiefly of invertebrates (del Hoyo et al. 1996, Snow and Perrins 1998). Breeding During the breeding season larval and adult Diptera and small beetles are the primary foods, particularly the larvae of mosquitoes and craneflies (Johnsgard 1981, del Hoyo et al. 1996). Non-breeding Outside of the breeding season the diet becomes more varied, with ants, Hymenoptera, waterbugs, annelids, small molluscs, crustaceans, freshwater mites and plant material being taken as well as Diptera and beetles (del Hoyo et al. 1996).
Breeding site The nest is a shallow cup on the ground in the open, sometimes covered with vegetation (del Hoyo et al. 1996, Snow and Perrins 1998).
The species is threatened on the south-east coast of India (Point Calimere) by illegal hunting (bird trapping), reservoir and marshland habitat alteration by salt-industries, and habitat degradation by diminishing rainfall (changing the salt regime) (Balachandran 2006). It is threatened at Walvis Bay in Namibia, a key wetland site in southern Africa, by habitat degradation (e.g. through changes in the flood regime due to road building, and wetland reclamation for suburb and port development), and disturbance from tourism (Wearne and Underhill 2007). This species is also susceptible to avian malaria (Mendes et al. 2005) and avian botulism (Blaker 1967, van Heerden 1974), so may be threatened by future outbreaks of these diseases.
Conservation Actions Underway
The following information refers to the species's European range only: The species is listed on Annex II of the Bern Convention.
Conservation Actions Proposed
The following information refers to the species's European range only: No conservation measures are thought to be currently needed for this species.
Text account compilers
Butchart, S., Ashpole, J, Ekstrom, J., Malpas, L., Wheatley, H.
BirdLife International (2020) Species factsheet: Calidris minuta. Downloaded from http://www.birdlife.org on 25/01/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/01/2020.