LC
Pectoral Sandpiper Calidris melanotos



Justification

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 is unknown, with increases and declines reported in difference parts of its range. The overall trend is therefore concluded to be unknown, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is estimated to be very large, hence it is 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.

Population justification
The population size was estimated as c.1.6 million in 2012 (Andres et al. 2012) but was recently substantially revised upwards to c.5.7 million (2.5-9 million) in Arctic Canada alone (Bart et al. in prep.). Given Andres et al. (2012) estimated c.1.1 million in northern Alaska, the North American population is thought to number at least 7 million breeding birds. The number breeding in Russia is effectively unknown, but high densities have been reported (Farmer et al. 2020). Overall, the global population is thought to number 4,000,000-15,000,000, with a best estimate of 8,000,000-15,000,000. An estimate of 1,220,000-1,930,000 birds has been made for the East Asian-Australasian Flyway (Hansen et al. 2022).

Trend justification
Trend unknown. Smith et al. (2023) used migration count data from the Atlantic coast to estimate  population reduction equivalent to 44.3% over three generations, though with wide confidence intervals of a reduction of 10.3-67.2%. However, this species primarily migrates south through the midcontinent and the trends in Smith et al. (2023) may not be especially meaningful (R. Lanctot in litt. 2024). Meanwhile, in the Arctic National Wildlife Refuge (Alaska, USA), the species' showed a significant increase between 2002/2004 and 2019/2022, from 52,978 to 96,217; a similar survey in the Teshekpuk Lake Special Area in north central Alaska showed a slight increase in number of individuals detected in 2007/2008 (42) to 2023 (265) (R. Lanctot in litt. 2024). Monitoring in the Chaun delta, Chukotka, Russia, has shown nest density to be positively correlated with spring weather conditions, and is expected therefore to increase in response to climate change; this appears to be being realised, with the species expanding its range across the Russian arctic (D. Solovyeva in litt. 2024)

Until these disparate trends can be adequately reconciled, the global population trend of this species is considered unknown.

Distribution and population

Breeds in northern Russia from eastern base of Taymyr Peninsula and the Khatanga Delta eastward along the arctic coastal plain to Alaska (USA)  and Arctic Canada. The majority of breeding birds appear to be concentrated in northern Alaska, north-west Canada, and east and central Siberia (Farmer et al. 2020). Birds chiefly migrate through North and Central America to winter in South America, chiefly from Peru, southern Bolivia and northern Argentina and Uruguay south to Patagonia (Chile, Argentina). Some birds also winter in Australasia and Oceania, particularly Australia, New Zealand and Polynesia. It is a regular vagrant to Western Europe with records scattered across the Western Palearctic and north Africa.

Ecology

Breeds on Arctic tundra, usually in wet boggy habitats. In the non-breeding seasons (passage and wintering) inhabits wide range of habitats including freshwater and brackish marshes, coastal and inland wetlands (including up to 4,500 m in the Andes), saltmarshes, flooded agricultural fields and grasslands, sewage works and coastal lagoons. Only very rarely uses mudflats (Farmer et al. 2020).

Threats

Poorly known, in large part because the population trend of this species is unknown. In North America, the expanding range of Red Fox Vulpes vulpes (see also Elmhagen et al. 2017, Gallant et al. 2020) causing increased rates of depredation, and hyperabundant Snow Geese Anser caerulescens and Ross’ Geese Anser rossii degrading habitat and causing increased predator densities (see, e.g., Flemming et al. 2019a, 2019b, 2019c) have been identified as plausible threats. The degradation and pollution of wetlands are also possible threats (Bart et al. in prep). Climate change was suggested as a pervasive threat in Bart et al. (in prep.) for North America, but in Russia the species is positively correlated with spring weather conditions, and is expanding its range possibly in response to climate change (D. Solovyeva in litt. 2024).

Conservation actions

Conservation Actions Underway
No targeted actions are known, although the species is covered by PRISM survey monitoring.

Conservation Actions Proposed
Protect and preserve important staging areas. Research threats, particularly on the breeding grounds. Undertake more extensive monitoring to better understand the species' global population trend.

Acknowledgements

Text account compilers
Berryman, A.

Contributors
Ekstrom, J., Butchart, S., Lanctot, R. & Solovyeva, D.


Recommended citation
BirdLife International (2024) Species factsheet: Pectoral Sandpiper Calidris melanotos. Downloaded from https://datazone.birdlife.org/species/factsheet/pectoral-sandpiper-calidris-melanotos on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/12/2024.