Archived 2015 topics: Bar-tailed Godwit (Limosa lapponica): uplist to Vulnerable?

Bar-tailed Godwit (BirdLife factsheet) breeds across the Arctic from northern Europe through Siberia to Alaska, wintering along the coasts of western Europe, Africa, the Middle East, South and Southeast Asia, Australia and New Zealand.

Globally, it has an extremely large range in both the breeding season and in winter, and hence does not approach the thresholds for Vulnerable under the range size criteria (B and D2). Its population size is also extremely large (999,000–1,049,000 individuals; Wetlands International 2015), and hence does not approach the thresholds for Vulnerable under the population size criteria (C and D1). Therefore, the only potentially relevant criterion is A, which relates to reductions in population size. Until recently, the population was thought to be declining slowly, but not sufficiently rapidly to approach the threshold for listing as Vulnerable under criterion A (at least a 30% decline over ten years or three generations, whichever is longer).

The following summary is based on that in Wetlands International (2015):

 

Population Breeds / winters Size (individuals) % total Trend
lapponica N Europe / W Europe 120,000 11-12% Stable/Increasing (BirdLife International 2015)
taymyrensis W Siberia / W & SW Africa 500,000 48-50% Moderately rapid decline? (c23-27% in three generations; extrapolated from Van Roomen et al. 2014)
taymyrensis C Siberia / S & SW Asia & E Africa 100,000-150,000 10-14% Unknown (Delany et al. 2009)
menzbieri & (anadyrensis) N Siberia / SE Asia to Australia 146,000 14-15% Very rapid decline (79.1% in three generations; Garnett 2015)
baueri E Siberia & W Alaska / China to Australia & New Zealand 133,000 13% Rapid decline (30.2% in three generations; Garnett 2015)
Total Global 999,000-1,049,000   Moderately rapid/rapid decline?

 

Trend in Europe (lapponica):

The breeding population trend is unknown. The wintering population trend is increasing (BirdLife International 2015).

Trend in W Africa (taymyrensis):

Van Roomen et al. (2014) report an estimated decline based on wintering counts for the period of 2003-2014, also long-term decline for the period of 1979-2014. Total wintering numbers were estimated at 745,803 in the 1980s, 516,920 in the 1990s and 497,433 (rounded to 500,000) in the 2010s.

Trend in East Africa (taymyrensis):

Reported as unknown by Wetlands International (2015). A large proportion of this population winters at Bar al Hikman, Oman (eg. 87,187 individuals in Dec 2013; de Fouw in litt. to Wetlands International).

Trend in East Asian-Australasian Flyway (menzbieri and baueri):

c.27-28% of the global population uses the flyway. BirdLife Australia’s Threatened Species Committee, which applies the IUCN Categories and Criteria at the national level, recently recommended the uplisting of the subspecies L. l. menzbieri from Vulnerable to Endangered (under criterion A2bc+3bc+4bc) in Australia (Garnett 2015), and the recommendation was subsequently accepted by the BirdLife Australia Research and Conservation Committee. The subspecies L. l. baueri remains classified as Vulnerable in Australia. The proposal was based on a detailed analysis of all monitoring data collected on shorebirds around Australia and New Zealand in the last 30 years (Studds et al. in prep) – see extract here:

 

Taxon Annual rate of decline Generation time Loss over three generations Action Plan status 2010 Recommended status 2015
 
L. l. menzbieri -0.061 8.9 -79.1 Vulnerable Endangered
L. l. baueri -0.014 8.9 -30.2 Vulnerable Vulnerable

 

The analysis used Bayesian binomial mixture models of non-breeding count data throughout Australia and New Zealand to estimate trends for subpopulations thought to follow different migration routes and summarized these estimates to yield flyway-level trends. Count data for each taxon were acquired from local and national databases in Australia and New Zealand. Many counts began in the early 1980s, but several key sites initiated counts in the 1990s.

For shorebirds of the East Asian-Australasian Flyway there is considerable concern that loss of intertidal stopover habitat in the Yellow Sea region of East Asia is driving population declines (Amano et al. 2010; Yang et al. 2011). Up to 65 percent of intertidal habitat in the Yellow Sea has been lost over the past 50 years, and habitat is currently disappearing at a rate of >1 percent annually owing to reclamation for agriculture, aquaculture, and other development (Murray et al. 2014). Current rates of Yellow Sea habitat loss seem likely to continue or accelerate owing to projected human population growth, much of it concentrated along the margins of the Yellow Sea.

Further evidence of genuine very rapid recent decline in the population of menzbieri comes from a study of adult survival in this species, Red Knot and Great Knot along the East Asian-Australasian Flyway. Whereas the survival in NW Australia in late winter remained constantly high, the survival during the time away from Australia started to decline in 2011. With an annual survival rate for Bar-tailed Godwit during 2011-2012 of 0.69, the study predicts that this population will halve within four years, and that only the immediate protection and safeguard of suitable staging grounds in the Yellow Sea region, during both northward and southward migration, may now help to prevent extinction (Piersma et al. submitted).

Summary and proposal

Despite the fact that population trends vary between different flyway populations, the overall picture seems to indicate that the species is declining by around 29-37% over three generations (27 years), depending on the interpretation of the data from West Africa in van Roomen et al. (2014). This assumes stability in the only population where the trend is unknown (taymyrensis wintering in the Middle East and East Africa) – were this to be declining the overall rate of decline would increase further. These data together suggest the species most likely warrants uplisting to Vulnerable under criterion A2bc+3bc+4bc.

Comments on the population size and trend estimates and threats to the species are welcomed, in particular from parts of the range where data are limited.

References

Amano, T., T. Szekely, K. Koyama, H. Amano, and W. J. Sutherland. 2010. A framework for monitoring the status of populations: An example from wader populations in the East Asian-Australasian flyway. Biological Conservation 143:2238-2247.

Delany, S.; Scott, D.; Dodman, T.; Stroud, D. 2009. An atlas of wader populations in Africa and Western Eurasia. Wetlands International, Wageningen, The Netherlands.

Garnett, S. T. 2015. BirdLife Australia Threatened Species Committee report to RACC. 23rd January 2015. Unpublished report.

Murray, N. J., R. S. Clemens, S. R. Phinn, H. P. Possingham, and R. A. Fuller. 2014. Tracking the rapid loss of tidal wetlands in the Yellow Sea. Frontiers in Ecology and the Environment 12:267-272 http://www.fullerlab.org/wp-content/uploads/2014/05/Murray-et-al-2014.pdf

Piersma, T. et al. submitted. Simultaneous declines in summer survival of three shorebird species signals a flyway at risk. PLOS Biology

Studds, C. E. et al. in prep. Dependence on the Yellow Sea predicts population collapse in a migratory flyway.

Van Gils, J. & Wiersma, P. (1996). Bar-tailed Godwit (Limosa lapponica). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53890 on 23 July 2015).

van Roomen, M., van Winden, E. & Langendoen, T. (2014) The assessment of trends and population sizes of a selection of waterbird species and populations from the coastal East Atlantic Flyway for Conservation Status Report 6 of The African Eurasian Waterbird Agreement. http://www.wetlands.org/Portals/0/EAF_selection%20of%20species2014_2.doc.pdf

Wetlands International (2015). “Waterbird Population Estimates” . Retrieved from wpe.wetlands.org on Wednesday 22 Jul 2015

Yang, H. Y., B. Chen, M. Barter, T. Piersma, C. F. Zhou, F. S. Li, and Z. W. Zhang. 2011. Impacts of tidal land reclamation in Bohai Bay, China: ongoing losses of critical Yellow Sea waterbird staging and wintering sites. Bird Conservation International 21: 241-259

This entry was posted in Africa, Archive, Asia, Australia, Europe & Central Asia, Middle East, Waterbirds. Bookmark the permalink.

9 Responses to Archived 2015 topics: Bar-tailed Godwit (Limosa lapponica): uplist to Vulnerable?

  1. Andy Symes (BirdLife) says:

    Hans Meltofte, chairman of the conservation committee of DOF/BirdLife Denmark, has recommended that the species is not uplisted until better evidence is established, and has provided the following extract from the draft of a forthcoming paper on Denmark’s most important staging area for waders outside of the Wadden Sea:

    The North European breeding and West European wintering lapponica flyway population is estimated to hold 120,000 individuals and be stable (Delany et al. 2009). However, according to the latest midwinter count data, this population has increased since the 1990s (Nagy et al. 2015). The birds passing Blåvandshuk south of Tipperne on active migration – probably primarily involving European breeders (Meltofte 1993) – also show no sign of decline; on the contrary numbers were increasing during 1964-2003 (Meltofte et al. 2008).

    The North Siberian breeding taymyrensis population that winter in West Africa is estimated to hold 600,000-700,000 individuals and to be “possibly decreasing”. Numbers of Bar-tailed Godwits have decreased in the Danish and Schleswig-Holstein parts of the Wadden Sea since the 1980s, while they have been stable in Niedersachsen and gone so much up in the Dutch part that totals for the entire Wadden Sea are stable or slightly increasing [check final wording] (Blew et al. 2013, JMMB XXXX). These birds include both populations, but Siberian breeders predominate among the birds utilizing the Dutch and Niedersachsen parts in May (Meltofte et al. 1994, Engelmoer 2008), and when analysed separately, taymyrensis numbers have also been stable in the Wadden Sea since monitoring began in 1987 (M. van Roomen in litt.). On the West African wintering grounds of the taymyrensis population on the other hand, numbers have gone down since counts began in 1979 with a challenging exception of a very high count in 2006 (van Roomen et al. 2015).

    In a longer time frame, the wintering area of Bar-tailed Godwits in West Europe has expanded north during the 20th century (Prater 1981: 111), giving further support to the notion above that these birds have shifted their winter and early spring distribution much in the same way as Grey Plovers (see above). These shifts are probably mainly the result of milder winters and earlier springs, but also reduced disturbance from shooting may be involved (Prater 1981, Tubbs 1996).

    MELTOFTE, H. & CLAUSEN, P. in print: Trends in staging waders on the Tipperne Reserve, western Denmark, 1929-2014. – Dansk Orn. Foren. Tidsskr. 110.

  2. Andy Symes (BirdLife) says:

    2014 proposal to list four subspecies of Bar-tailed Godwit for Concerted and Cooperative Action under CMS:

    http://www.cms.int/sites/default/files/document/COP11_Inf_44_Proposals_for_Concerted_and_Cooperative_Action_Bird_Species_for_Consideration_by_COP11_0.pdf

  3. Andy Symes (BirdLife) says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2015 Red List would be to treat:

    Bar-tailed Godwit as Near Threatened under criterion A2+3+4.

    There is now a period for further comments until the final deadline of 31 August, after which the recommended categorisation will be put forward to IUCN.

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

  4. Marc van Roomen says:

    The evidence of increase in the lapponica population and the decrease in the taymyrensis population is I think robust. Based on IWC counts from the whole wintering range in their flyways. The report with analyses on the Status of coastal waterbird populations in the East Atlantic Flyway will appear on 15 September.

  5. The rapid decline in numbers along the South-east coast of India Particularly in the Gulf of Mannar region where over 300 individuals regularly occur at one of the Islands namely Manali Island. now there number never exceeded 50 indicates their decline. May be uplisted to Near-threatened.

  6. Andy Symes (BirdLife) says:

    The following comments were provided by the Alaska Shorebird Group:

    The Alaska Shorebird Group (ASG) was established in 1995 to raise public awareness about shorebirds; to promote research, monitoring, management, conservation and education relevant to shorebirds in Alaska; to provide a forum for the exchange of information about shorebirds among biologists, managers, and the public; and to promote the range-wide management and conservation of shorebirds that spend part of their life cycle in Alaska. Our group includes representatives from federal and state agencies, non-governmental organizations, academia, and the general public. Many members of the ASG have been directly involved in study and conservation of Bar-tailed Godwits (Limosa lapponica) in Alaska and elsewhere in the East Asian-Australasian Flyway (EAAF). We are writing to support the listing of the Bar-tailed Godwit as Vulnerable within the IUCN framework based on reductions in population size (criterion A2, based on direct observation). As noted in BirdLife’s Globally Threatened Bird Forum, the global population size of the species as a whole is quite large, but the recent steep population declines detected in both the menzbieri and baueri populations (Conklin et al. in revision) warrant the up-listing of the species as a whole to Vulnerable. These populations rely on resources throughout the EAAF during their annual cycles, and degradation and continuing threats to shorebird habitats in this region are well documented (Murray et al. 2015, Ma et al. 2014). Bird species in the EAAF face immediate conservation threats (MacKinnon et al. 2012), threats that we believe are already reflected by severe population declines noted not only in these two populations, but also in many others (Piersma et al. in revision, Conklin et al. 2014, MacKinnon et al. 2012, Bamford et al. 2008). To overlook the dire conservation situation of Bar-tailed Godwits in the EAAF due to the status of Bar-tailed Godwits elsewhere in its range ignores the recognized importance of preserving the diversity of discrete populations that constitute a whole. Additionally, it overlooks the regional importance of Bar-tailed Godwits as cultural resources for millions of people throughout the EAAF. We thank you for the opportunity to comment on the conservation status of this iconic avian resource.

  7. David Melville says:

    Although apparently too late, I would like to support the submission by the Alaskan Shorebird Group.

    Piersma et al suggest a halving of the population of menzbieri in 3-4 years. A study by Conklin et al (Emu, submitted) indicates a halving of the population of baueri in 10 years.

    Rate of loss of intertidal habitat in the Chinese Yellow Sea is closer to 4% p.a. in recent years (Piersma et al. in review) – rather than the 1% in Murray et al.

    Not only is habitat being lost directly to reclamation, but the remaining habitat is in most parts of the Chinese Yellow Sea coast subject to serious degradation from a range of activities including aquaculture, chemical run off, intertidal wind farms etc (Melville et al. Emu, submitted).

    Notably there has been a major crash in benthic prey stocks at Yalujiang NNR, Liaoning where >40% of the total baueri population stages on northward migration in both 2014 and 2015 (Fudan University unpublished). The cause(s) of this remain to be determined.

  8. Andy Symes (BirdLife) says:

    Recommended categorisation to be put forward to IUCN

    Following further review, there have been no changes to our preliminary proposal for the 2015 Red List status of this species.

    The final categorisation will be published on the BirdLife website in late October and on the IUCN website in November, following further checking of information relevant to the assessment by BirdLife and IUCN.

  9. Andy Symes (BirdLife) says:

    Szabolcs Nagy has provided the following comment:

    Dear All,

    Just for information, the report on Status of coastal waterbird populations in the East Atlantic Flyway 2014 is now available at http://s1.sovon.nl/upload/uploadmanager/108208130020150911103256.pdf. This report contains the results of the trend analyses we referred to in earlier contributions.

Comments are closed.