Sharp-tailed Sandpiper Calidris acuminata


Justification of Red List Category
Based on data from Australia, this species is estimated to be undergoing a rapid population decline (of c.45% over three generations) because of habitat degradation, pollution and climate change. As such it is assessed as Vulnerable.

Population justification
Hansen et al. (2022) estimated the population in 2016 to number 120,684 using a breeding range and density estimate, or 85,829 from a spatially extrapolated estimate. The latter value is considered to be most accurate. Using the same underlying data (near-comprehensive count data from Australia, where >90% of the population winters) and trends derived from Clemens et al. (2016, 2019) and Clemens (2017), Clemens et al. (2021) estimate the population in 2020 to have numbered 72,900 mature individuals. Considering these data, the population is here estimated at 60,000-120,000, with a best estimate of 73,000.

Trend justification
Wetlands International (2019) considered the population trend to be unknown, however data exist from the wintering area that suggest a recent rapid decline. In Australia, where >90% of the world population winters (Clemens et al. 2021), data from a long-running (since the 1980s), continent-wide citizen science monitoring effort indicate a recent steep decline after temporal and spatial variability are accounted for (see Clemens 2017). The declines in the number of individuals recorded in Australia are inferred to represent the global rate of reduction in mature individuals. The estimated population of C. acuminata in 2016 in Australia was 85,000 (Hansen et al. 2022). By 2020, the abundance was estimated to be 72,900, based on an extrapolation of the 2016 data using trends derived from Clemens et al. (2016, 2019) and Clemens (2017). Over three generations (14.6 years; Bird et al. 2020), estimated population declines have been: 60% (Clemens et al. 2016), 24% (Clemens 2017), 47% (Clemens et al. 2019; Waterbird meta-analysis) and 52% (Clemens et al. 2019; Generalised Additive Model). The population is therefore estimated to be declining at a rate of 24-60% over three generations, with a best estimate (following Clemens et al. 2021) of 45%. Moreover, juvenile birds staging in Alaska before the onset of the autumn migration are in decline and the species has been included in the Red Alaska Watchlist (Warnock 2017). With continuing invasion of cordgrass on its staging sites (Melville et al. 2016) and climate change increasing the frequency of and severity of droughts (which has been demonstrated to impact the global population [Clemens 2017]), this decline is predicted to continue at approximately the same rate.

Distribution and population

Breeds in north-central and north-east Siberia from Lena Delta to the River Kolyma, Russia. Occurs throughout East Asia and Australasia on passage with critical staging/stopover sites in China and South Korea as well as Alaska, U.S.A. Most birds winter in Australia, with smaller numbers in Indonesia, New Zealand and Papua New Guinea. It has occurred as a vagrant in numerous countries throughout Asia and Europe.


The species breeds on tundra of low Arctic and subarctic, especially damp hillock tundra and moss-sedge bogs with drier, shrub-covered hummocks (up to 2–3 m high).  During non-breeding season, the species uses a wide variety of coastal and inland wetlands (many ephemeral), including coastal saltmarshes, intertidal mudflats, shallow brackish lagoons, flooded grassland, river mouths and rice fields (Brazil 2009). The species occurs between sea level and 800 m (Quintero and Jetz 2018).


In its wintering range in Australia the major threat is from drought (Clemens 2017), the frequency and severity of which are predicted to increase as the climate changes (Evans et al. 2017). Elsewhere, the main threats are changes to coastal stopover locations, particularly along the coast of the Yellow Sea where there is rapid development for aquaculture and industry, invasion by cord grass Spartina alterniflora, pollution from domestic, industrial and aquaculture discharges, oil and pesticides, and hunting and incidental drowning in fishing nets and traps. The habitat area is also shrinking through a combination of restricted inflow of sediments from increasingly dammed rivers (Murray et al. 2014, Melville et al. 2016) and sea level rise with sea walls at many sites preventing suitable habitat migrating inland. There is little understanding of how to manage these threats, whilst there is limited attempts to implement such management knowledge as is available. China stopped major reclamation in early 2018, and designation of migratory bird sanctuaries along the coast of the Yellow Sea and Bohai Gulf as a UNESCO World Heritage Site (Melville 2018, UNESCO 2019) should reduce some risks, although major political, social and economic hurdles remain.

Conservation actions

Conservation Actions Underway
Areas of the East Asian Australasian Flyway, particularly those along the Yellow Sea, continue to be identified for habitat protection and active management of some sites invaded by cordgrass. China stopped major reclamation in early 2018 and designation of migratory bird sanctuaries along the coast of the Yellow Sea and Bohai Gulf as a UNESCO World Heritage Site (Melville 2018, UNESCO 2019) should reduce some risks, although major political, social and economic hurdles remain (Clemens et al. 2021).

Conservation Actions Proposed
Develop climate change adaptation plans. Develop strategies for managing multiple threats to stopover sites in East Asia and optimise body condition of birds leaving Australia. Protect non-breeding habitat and work with governments throughout the Flyway to retain critical areas of habitat. Continue to monitor population trends.


Text account compilers
Butchart, S., Berryman, A., Ekstrom, J.

Warnock, N.

Recommended citation
BirdLife International (2023) Species factsheet: Calidris acuminata. Downloaded from on 23/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from on 23/03/2023.