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). 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 very 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 at 738,000-935,000 (Wetlands International 2015). This roughly equates to 490,000-630,000 mature individuals. National population estimates include 10,000 individuals on migration and 1,000-10,000 wintering individuals in China, 50-10,000 wintering individuals in Taiwan (China), 1,000-10,000 individuals on migration and 1,000-10,000 wintering individuals in Korea, 1,000-10,000 individuals on migration and 1,000-10,000 wintering individuals in Japan, and 10,000-100,000 breeding pairs and 1,000-10,000 individuals on migration in Russia (Brazil 2009). The European population is estimated at 5,000-10,000 pairs, which equates to 10,000-20,000 mature individuals (BirdLife International 2015).
The overall population trend is decreasing, although some populations have unknown trends (Wetlands International 2015). In North America, the species has had stable trends over the last 40 years (based on Partners in Flight; A. Panjabi in litt. 2017). The European population trend is unknown (BirdLife International 2015).
Behaviour This species is fully migratory (del Hoyo et al. 1996). It departs its breeding grounds from late-July to September (southward movements continuing into November) and returns from late-May to June (Hayman et al. 1986, del Hoyo et al. 1996). It breeds from May to August in solitary well-dispersed pairs and forages alone or in small loose flocks of up to 30 individuals (Johnsgard 1981, Hayman et al. 1986, del Hoyo et al. 1996). It is gregarious during the winter however, often roosting in large flocks containing up to several thousand individuals (del Hoyo et al. 1996).
Habitat Breeding The species nests in the high Arctic in both upland and valley locations between the treeline and the coast, utilising dry stony tundra with sedge, moss, lichen, grass or dwarf birch, peat ridges in tundra marshes, dry exposed ridges, riverbanks, raised sand or gravel beaches, and rocky slopes (Johnsgard 1981, del Hoyo et al. 1996, Snow and Perrins 1998). Non-breeding Outside of the breeding season the species frequents intertidal mudflats, saltmarshes, sandflats and beaches of oceanic coastlines, bays and estuaries (Johnsgard 1981, del Hoyo et al. 1996). During migration it may also be found inland on lakes, pools or grasslands (del Hoyo et al. 1996).
Diet Breeding During the breeding season the diet of this species consists largely of adult and larval insects such as beetles and Diptera as well as some plant matter (e.g. grass seeds and stems) (del Hoyo et al. 1996). Non-breeding When on the coast in its wintering range the species takes marine polychaete worms, molluscs and crustaceans (e.g. crabs, sand shrimps), occasionally also taking insects (e.g. grasshoppers and beetles) or earthworms when in inland habitats on passage (Johnsgard 1981, del Hoyo et al. 1996).
Breeding site The nest is a shallow scrape on dry ground in exposed, stony sites, neighbouring nests not less than 400 m apart (del Hoyo et al. 1996, Snow and Perrins 1998).
Management information In the UK there is evidence that the removal of Common Cordgrass (Spartina anglica) from tidal mudflats using a herbicide is beneficial for the species (Evans 1986).
The following information refers to the species's European range only: Populations fluctuate from year to year with poor weather and predator pressure in years of low lemming numbers (Hagemeijer and Blair 1997). Warmer temperatures brought about by climate change are thought to affect this species (Maclean et al. 2008). It is also threatened by disturbance from recreational activities (Cutts et al. 2009), intertidal oyster culture (Gittings and O'Donoghue 2012) and urban and industrial development.
Conservation Actions Underway
The species is listed on Annex II (B) of the EU Birds Directive. The following information refers to the species's European range only: In the U.K. there is evidence that the removal of Common Cordgrass (Spartina anglica) from tidal mudflats using a herbicide is beneficial for the species (Evans 1986).
Conservation Actions Proposed
The following information refers to the species's European range only: Infrastructure development, human disturbance and marine aquaculture at breeding sites needs to be stopped.
Text account compilers
Malpas, L., Ekstrom, J., Ashpole, J, Butchart, S., Everest, J.
Dowsett, R.J. & Panjabi, A.
BirdLife International (2021) Species factsheet: Pluvialis squatarola. Downloaded from http://www.birdlife.org on 25/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/10/2021.