Dunlin (Calidris alpina)

Red List Team (BirdLife International)

Dunlin (Calidris alpina)

14 thoughts on “Dunlin (Calidris alpina)

  1. Italian wintering population 2011-2020, mean 99,339 inds, 90% at the top 26 wetlands, TRIM: moderate increase (also in the long term, 1993-2020, moderate increase). May have locally benefited from current trend toward milder winters (?) and decrease in generalized hunting disturbance (??). Both ssp alpina and centralis are well represented.

  2. In Lebanon, in the past, a regular passage migrant over the Palm Islands Nature Reserve according to G. Ramadan-Jaradi and M. Ramadan-Jaradi (2001). However, numbers have been decreasing in recent years with 10 individuals counted on the Beirut coast in 2023 and 1 individual over the Palm Islands in 2024.

  3. Subspecies sakhalina has stable nest density in the Chaun delta, Chukotka, Russia, in 2011-2023 based on the nest plots searches (5 plots 0.16 ha each; D. Solovyeva, unpublished data).

  4. In California, USA
    Tomales Bay = 77% decrease
    Dunlin using the Pacific Americas Flyway south of Alaska are C. a. pacifica, a race that breeds in subarctic and Arctic Western Alaska (Gill et al. 2013, Warnock and Gill 2020). They are currently considered to be of Moderate Conservation Concern (U.S. Shorebird Conservation Plan Partnership 2016, Alaska Shorebird Plan 2019). However, our monitoring and other efforts in California indicate that Dunlin wintering in California have significantly declined (77% during this study, Stenzel and Page 2018, Meehan et al. 2018). Likewise, winter counts in the Pacific Northwest indicate declining populations (Crewe et al. 2012, Meehan et al. 2018, but contra Drever et al. 2014 for spring migration). One hypothesis is that wintering Dunlin populations are contracting northward with a warming and changing climate (Fernandez et al. 2010), as is the case with West Coast wintering Pacific Brant (Branta bernicla nigricans) whose breeding population is increasingly over-wintering along the Alaska coast instead of California and Mexico due to fewer freezing degree days and less ice covering foraging habitat in Alaska (Ward et al. 2009). Changing climatic conditions have also been suggested as a potential key factor in the decline of wintering Ruddy Turnstones (Arenaria interpres) in California (Pandolfino and Helmericks 2005), a high Arctic-breeding species that prior to the late 1980s was commonly seen at Tomales Bay but is now rare (Shuford et al. 1989).

    See references in
    Warnock, N., S. Jennings, J. P. Kelly, E. Condeso, and D. Lumpkin. 2021. Declining wintering shorebird populations at a temperate estuary in California: a 30-year perspective. Ornithological Applications 123:1-19.

  5. Monitoring of migratory birds in Finland (East Atlantic flyway).
    Annual standardized monitoring counts from the Hanko Bird Observatory show short-term increase (+142%; 2010-2019 -> 2020-2022) or long-term increase (+110%; 1979-1999 -> 2020-2022):
    https://haahka.laji.fi/?_inputs_&language=%22en%22&tabs=%22species%22&species=%22Calidris%20alpina%22
    Annual variation in numbers is relatively high, but also no clear declines between the recent decades.

    Similarly trends in the casual observations through the national online portal of Birdlife Finland (Tiira.fi) suggest clear signs of declines. The data has been analysed using only one observation per 100 km2 square per day: observation with the highest number of individuals during the spring / autumn migration season. The national annual sum was the additive sum of the squares from a given year. The method has been explained in
    https://lintulehti.birdlife.fi:8443/pdf/artikkelit/2576/tiedosto/Linnut_VK2017_080-091_Uhanalaiset_ja_harvalukuiset_ARK_artikkelit_2576.pdf#view=FitH

    Annual cumulative means:
    Spring 2007-2011 51,684 -> 2019-2023 69,514 = +34 %
    Autumn 2007-2011 58,524 -> 2019-2023 63,131 = +8 %

  6. Annual breeding population numbers in Kilpisjärvi study area in NW Finland have increased during 2005-2023: Annual number of terrotories of c. 40 km2 survey area:
    2005 14
    2007 16
    2008 7
    2009 8
    2010 12
    2011 22
    2012 5
    2013 12
    2014 16
    2015 42
    2016 13
    2017 31
    2018 29
    2019 37
    2020 35
    2021 36
    2022 48
    2023 85

  7. As per the State of India’s Birds, Dunlin is declining rapidly in the longer term as well as post 2015 (till 2022). Subspecies is unclear but quite likely centralis is involved, which has been referred to have stable population in the above account.

    https://stateofindiasbirds.in/species/dunlin/
    Current Annual trend from 2015 till 2022.
    -6 (-7.99, -4.02) – 95% CI in the brackets, at least a 4% annual decline with 95% confidence.

  8. In India this species is uncommon especially along the east coast. This species in scarce number is always mixed either with the large Curlew sandpiper and Lesser Sand Plover flocks , it is difficult to make counts. However, its numbers are relatively more common than the East coast. Probably both may be different subspecies. Their occurrences at South-east coast are mostly birds caught along with other waders. But along the west coast it could be recognized particularly during the northward passage when they are in breeding plumage. But the birders from the west coast also mentioning about its decline.

  9. In northern Alaska, declines in estimated population size of the subspecies of arcticola Dunlin have occurred on the breeding grounds in the Arctic National Wildlife Refuge (2002/2004: 10,506, SE = 4,112; 2019/2022: 1,115, SE = 488). Preliminary results from similar surveys on the Teshekpuk Lake Special Area in north central Alaska also showed declines (2007/2008: 218 birds counted compared to 2023 with 198 birds counted) over 53 repeat survey plots. We plan another year of surveys in 2024 and then will make population estimates for this latter area (S. Brown and R. Lanctot, unpubl. data).

    A Dunlin webinar / workshop held on the 22 April 2024 indicated long-term declines in adults during winter counts in Japan and South Korea, but an increase in the number of adults counted during winter in Taiwan and China (although variable trends among survey sites at each geographic location). Winter ground counts can include four subspecies, including sakhalina, kistchinskii, actites, and arcticola so hard to know what subspecies is being counted. However, prior tracking work has confirmed that arcticola subspecies likely winters more in Japan (Lagasse et al. 2022) and thus declines there reinforce declines observed on the subspecies breeding grounds.

    Threats identified at the Dunlin webinar/workshop include loss or modification of intertidal habitat due to rising sea levels, expansion of spartina, expansion of solar farms, change or decline of food resources, and human development (e.g., Manilla airport construction). Dunlin are known to use inland areas such as fish ponds, salt flats, etc., especially when high tides cause no intertidal areas to be available.

    Comment on the map: The passage portion of the map is pretty worthless as I know Dunlin do not migrate across such a large area.

    Strongly advise IUCN to consider breaking species into subspecies categories when impacts to individual subspecies are likely to be much different from one another.

  10. Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 3 May 2024. We will now analyse and interpret all information, and we will post a preliminary decision on this species’ Red List status on this page on 3 May 2024, when discussions will re-open.

  11. Preliminary proposal

    Based on available information, our preliminary proposal for the 2024 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.

    There is now a period for further comments until the final deadline on 13 May 2024, after which the recommended categorisations will be put forward to IUCN.

    The final 2024 Red List categories will be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  12. Dunlins are normally recorded in the coastal Gambia, particularly the lagoons, and the middle parts of the Gambia in some of the Key National parks and wetlands but beyond that limited or few records
    still with all the records the numbers are not more than 300 species

    One of the lagoons that use to hold a sizeable numbers of dunlins from 20 up to 50 is called TANBI in Banjul but now the wetlands have been degraded and the birds have not been seen in TANBI for many years now

  13. Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret available information, posting a final decision on this species’ Red List status on this page on 20 May 2024.

  14. Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Dunlin is recommended to be listed as Near Threatened, approaching threatened thresholds under Criteria A2b+4b.

    Many thanks for everyone who contributed to the 2024.2 GTB Forum process. The final 2024 Red List categories will be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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