NT
Curlew Sandpiper Calidris ferruginea



Justification

Justification of Red List Category
This species is listed as Near Threatened owing to a global population decline which is thought to approach the threshold for Vulnerable under the population size reduction criterion (A4abc). The species has an extremely large range and the overall population trend is very difficult to determine due to varying trends in different populations along different flyways. The population using the East Asian-Australasian Flyway is thought to be experiencing severe declines due to habitat loss in the Yellow Sea, and the population using the East Atlantic Flyway may also be undergoing declines. Should new information arise providing clarification on the overall population trend it may warrant uplisting or downlisting.

Population justification
The global population is estimated to number c.1,085,000-1,285,000 individuals (Wetlands International 2015). The minimum European population in winter is estimated at 1,000-1,800 individuals, which equates to 690-1,200 mature individuals (BirdLife International 2015). The population wintering in West Africa is estimated at 350,000-450,000 individuals (van Roomen et al. 2015). The East Asian-Australasian Flyway population has been estimated at 90,000 individuals (Hansen et al. 2016).

Trend justification
Population trends are very difficult to determine for this species, however overall it is suspected to be declining. The population wintering in south-west Asia, the Middle East and east and southern Africa is estimated to have undergone a moderate long-term increase and a large decline in the short-term (since c. 2007) (Nagy et al. 2014, M. Taylor in litt. 2015). However the data had limited coverage, particularly in the Red Sea and southern Gulf. A wintering population of c. 45,000 individuals at Walvis Bay and Sandwich Harbour in Namibia was stable between 1990 and 2013 (Simmons et al. 2015).

In West Africa count data show the population experienced a short-term decline between 2003 and 2014 and a long-term decline between 1979 and 2014 (32.9% decline over three generations (23 years)) (van Roomen et al. 2014). At Banc d'Arguin (Mauritania) and Bijagos (Guinea Bissau), the strongholds of the West African wintering population, the population has been decreasing (M. van Roomen in litt. 2015). However Dodman (2014) did not find a population decline, instead suggesting that the population was continuing to increase. This population trend is therefore uncertain. The population trend in the south Asian wintering population is unknown (Wetlands International 2015). Approximately 11-12% of the global population uses the East Asian-Australasian Flyway. An analysis of monitoring data from around Australia and New Zealand estimated the population had declined by 80.5% in three generations (Studds et al. in prep.). The decline observed in Australia may be representative of the whole flyway, however Amano et al. (2010) found no clear trend between 1978 and 2008.

Distribution and population

The species breeds across Arctic Siberia from the Chosa Bay to Kolyuchinskaya Gulf (north Chukotskiy Peninsula) (Russia) (Lappo et al. 2012), and winters from sub-Saharan Africa through the Middle East and south and south-east Asia to Australasia (van Gils and Wiersma 1996). In the western Palearctic the species follows three migratory routes: down western European coasts to West Africa; across eastern Europe via the Black Sea and Tunisia to West Africa (following the coast of North Africa or via Mali); and via the Black Sea and Caspian Sea and across the Middle East and Rift Valley lakes to southern and eastern Africa (Van Gils and Wiersma 1996). On return migration few birds use the western European flyway, instead moving up via Tunisia and Sivash (north Crimea). Birds that move south through Sivash winter in east, central and southern Africa and probably migrate north via the Caspian Sea. Birds also move across Siberia to India, continuing down through south-east Asia to Australia but many birds winter in southern India and Sri Lanka, they may also move overland to east Asia and via the coast of China to Australia (Van Gils and Wiersma 1996).

Ecology

This species breeds on slightly elevated areas in the lowlands of the high Arctic especially on southward-facing slopes, as well as along the coast and islands of the Arctic Ocean (Johnsgard 1981, del Hoyo et al. 1996). It shows a preference for open tundra with marshy, boggy depressions and pools (del Hoyo et al. 1996, Snow and Perrins 1998, Lappo et al. 2012) from melting permafrost and snow (Snow and Perrins 1998). The nest is a cup positioned on the margins of marshes or pools, on the slopes of hummock tundra, or on dry patches in Polygonum tundra (del Hoyo et al. 1996). In the winter the species chiefly occurs on coastal brackish lagoons, tidal mud- and sand-flats, estuaries, saltmarshes (del Hoyo et al. 1996, Snow and Perrins 1998), exposed coral, rocky shores and tidewrack on sandy beaches (Urban et al. 1986), and also inland on the muddy edges of marshes, large rivers and lakes (both saline and freshwater), irrigated land, flooded areas (del Hoyo et al. 1996), dams (Urban et al. 1986) and saltpans (Khomenko 2006). On the breeding grounds the diet of this species consists mainly of insects, such as the adults, pupae and larva of Diptera (e.g. midges, craneflies (Johnsgard 1981)) and beetles, as well as bugs and leeches (del Hoyo et al. 1996). In the winter its diet consists of polychaete worms, molluscs, crustaceans (such as amphipods, brine shrimps and copepods), and occasionally insects and seeds (del Hoyo et al.1996). It is a full migrant, moving long distances by well-travelled routes (del Hoyo et al. 1996, Snow and Perrins 1998).

Threats

The key threat in the East Asian-Australasian Flyway population is thought to be loss of stopover habitats in the Yellow Sea (see Melville et al. 2016). In China and South Korea important migrational staging areas of this species around the coast of the Yellow Sea are being lost through land reclamation, and degraded as a result of declining river flows (from water abstraction), increased environmental pollution, unsustainable harvesting of benthic fauna and a reduction in the amount of sediment being carried into the area by the Yellow and Yangtze Rivers (Barter 2002, Barter 2006, Kelin and Qiang 2006). These losses are thought to be driving declines in shorebird populations (Amano et al. 2010, Yang et al. 2011, Melville et al. 2016). It is estimated that up to 65% of tidal flats in the Yellow Sea region have been lost over the past five decades, with an annual loss of 1.2% per year since the 1980s (Murray et al. 2014).

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 also threatened at Walvis Bay in Namibia, a key wetland site in southern Africa, by habitat degradation (e.g. changes in the flood regime due to road building, and wetland reclamation for suburb and port development), and disturbance from tourism (Wearne and Underhill 2005). This species is susceptible to avian influenza (Melville and Shortridge 2006, Gaidet et al. 2007) and avian botulism (Blaker 1967, van Heerden 1974) so may be threatened by future outbreaks of these diseases.

Conservation actions

Conservation and Research Actions Underway
The species is listed on Annex II of the Bern Convention, as well as being listed as part of AEWA and CMS.

Conservation and Research Actions Proposed
Conduct research to better understand the species's dependence on key migratory staging sites, and increase knowledge of the impacts of disturbance (Anon. 2015). Protect remaining intertidal habitats across the species's range (including the Yellow Sea) to prevent further habitat loss and degradation (Yang et al. 2011, Anon. 2015), and work with governments along the East Asian – Australasian Flyway to prevent destruction of key migratory staging sites (Anon. 2015). Manage important sites to reduce the impact of disturbance (Anon. 2015). Continue and expand monitoring schemes. Raise awareness of the species. Incorporate requirements for this species and others into coastal planning (Anon. 2015).

Identification

18-23 cm medium-sized sandpiper. Longish neck and legs and long, decurved bill. Head, neck and all upperparts rusty rufous to deep chestnut-red, with dark streaks on crown. Mantle and scapulars dark brown with chestnut and whitish fringes. Wing coverts greyer. Female normally has longer bill, paler and more likely to have white barring on underparts. Non-breeding adult plain grey above, white below, white supercilium and sides of breast washed grey. Juvenile similar to non-breeding adult (Van Gils and Wiersma 1996).

Acknowledgements

Text account compilers
Malpas, L., Westrip, J., Ashpole, J, Ekstrom, J., Butchart, S., Symes, A.

Contributors
Szabo, J., Balachandran, S., van Roomen, M., Vyas, V., Nagy, S., Porter, R., Taylor, M., Meltofte, H.


Recommended citation
BirdLife International (2017) Species factsheet: Calidris ferruginea. Downloaded from http://www.birdlife.org on 21/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/10/2017.