Note:
This article was originally published in Stilt 60
(2011) the journal for the Australasian
Wader Studies Group and was kindly submitted by
Philip D. Round.
During
routine monthly surveys of over-summering shorebirds and other
waterbirds conducted by the Wildlife Research Division of
the Department of National Parks, Wildlife and Plants Conservation
of the Thai government, a single Spoon-billed Sandpiper Eurynorhynchus
pygmeus was found feeding among Red-necked Stints Calidris
ruficollis on newly accreting intertidal mudflats at
Khok Kham, Samut Sakhon Province, Thailand (c. 13° 31’
N; 100° 19’ E) on 19 July 2010. Many shorebirds
display delayed maturity, not returning to natal sites until
their second or third year (Loftin 1962, Summers et al.
1995, Rogers et al. 2006) and it has long been assumed
that first-year Spoon-billed Sandpipers do likewise (Tomkovich
1995, Zöckler et al. 2010a). This appears to
be the first documented record of a Spoon-billed Sandpiper
over-summering in the non-breeding grounds. Given the critically
endangered status and ongoing rapid population decline of
Spoon-billed Sandpipers (Zöckler et al. 2010a,
b), this over-summering record is highly significant.
The same
individual was photographed by SS almost one month later,
on 16 August 2010, when it roosted on saltpans. Its primaries
were in active moult, with score being “555554[1 or
2] 000” and the tertials had been dropped or were growing.
A few black-centred, breeding plumage feathers were visible
in the mantle and scapulars, but the bird was otherwise in
grey, non-breeding plumage (Figures 1 and 2).
The outermost
three (unmoulted) primaries were extremely bleached, brownish
and pointed, supporting the supposition that this was a first-summer
bird. Although firstyear shorebirds frequently renew a few
outer primaries in a partial post-juvenile moult, some do
not, and there are many species in which only a proportion
of the population undergoes such a moult (Higgins & Davies
1996, Marchant & Higgins 1993, D. Rogers, in litt.).
While the detailed ontogeny of the moult of Spoon-billed Sandpiper
appears to be unreported, the extreme wear and bleaching of
the outer primaries of the present individual was thought
typical among unmoulted first-summer shorebirds. Additionally,
the primary moult (more than 50% completed by mid-August)
was too advanced to indicate normal post-breeding moult of
an adult (C.D.T. Minton, in litt., D. Rogers,
in litt.).
What
was thought to be the same bird was seen on 17 and 21 September
when its stage of moult had progressed to the extent that
it more or less resembled “typical” nonbreeding
adults (S. Daengphayon, pers. comm.). The latter sightings
still pre-dated the arrival of non-breeding Spoonbilled Sandpipers
in the Thai Gulf, usually occurring in October (Round &
Gardner 2008).
Figure 1. Over-summering Spoon-billed Sandpiper
with wing extended, enabling determination of primary moult
status. Khok Kham, Samut Sakhon Province, Thailand, 16 August
2010 (Photo: Smith Sutibut)
Figure 2. Over-summing Spoon-billed Sandpiper
showing upperparts feathering. Khok Kham, Samut Sakhon Province,
Thailand, 16 August 2010 (Photo: Smith Sutibut).
Khok
Kham and nearby sites in Samut Sakhon Province constitute one
of two major clusters of sites in the Thai Inner Gulf where
about 10–20 Spoon-billed Sandpipers regularly winter (Nimnuan
& Daengphayon 2008, Round & Gardner 2008). The initial
sighting, on newly accreting mudflats, may be highly relevant
to the habitat preference of Spoon-billed Sandpipers which,
in some parts of their non-breeding range (especially the Meghna
Delta of Bangladesh), appear to favour accreting shorelines.
(Enam ul-Haque, in litt.). The observation was made at the site
of a conservation project which is successfully reversing coastal
erosion using traditional methods (bamboo stakes) instead of
intrusive concrete sea-walls, administered by the Department
of Marine and Coastal Resources, in collaboration with the local
community. Such accreting sites may be a valuable though highly
transient resource for Spoon-billed Sandpipers. Experience in
Bangladesh shows that as the substrate stabilises and compacts,
Spoon-billed Sandpipers are among the first shorebirds to disappear,
presumably moving elsewhere (Enam ul-Haque, in litt.). In Thailand,
more coastline is eroding rather than accreting, and erosion
is worsened by subsidence (caused by the unregulated extraction
of ground water), reduced sediment inflow due to dam construction
on rivers, and unzoned developments in the coastal zone. At
least 130 sq km in 18 Thai coastal provinces were planted with
mangroves during 1998–2003 (Round & Gardner 2008)
to offset erosion. Since provincial and national authorities
frequently choose to plant mangrove seedlings on mudflats, overtaking
the process of natural succession, this could further deprive
Spoon-billed Sandpipers and other shorebirds of key intertidal
feeding areas. Integrated management and zoning of the both
onshore and offshore habitats along the Inner Gulf coast should
be adopted so as to restrict inappropriate developments, reduce
erosion, and rehabilitate both onshore and offshore habitats.
This would safeguard both shorebirds and other biodiversity
values, and sustain the traditional (salt-farming and inshore
fishing) lifestyles of the human inhabitants.
ACKNOWLEDGEMENTS
We thank Enam ul-Haque, David Melville, Clive Minton, Danny
Rogers and Christoph Zöckler for their comments on drafts
of this manuscript, and Suchart Daengphayon for sharing details
of his Spoon-billed Sandpiper sightings. We also thank an
anonymous reviewer for comments on an earlier version of this
manuscript. Philip Round is supported by The Wetland Trust.
Nimnuan, S. & S. Daengphayon. 2008. The survey of population,
distribution and habitat of Spoon-billed Sandpiper in the Inner
Gulf of Thailand. Bird Conservation Society of Thailand
Bulletin25(4): 35–36. (Thai language).
Rogers, D.I., C.D.T. Minton, A.N. Boyle, C.J. Hassell &
A. Silcocks. 2006. 'Growing up slowly by the sea-side: Age of
first northwards migration of shorebirds from Australian nonbreeding
grounds'. Chapter 10 in Rogers, D.I. Hidden costs: challenges
faced by migratory shorebirds living on intertidal flats.
PhD thesis, Charles Sturt University, Albury, Australia.
Summers, R.W., L.G. Underhill, & R.P. Prys-Jones. 1995.
Why do young waders in southern Africa delay their first return
migration to the breeding grounds? Ardea83:
351–357.
Tomkovich, P. S. 1995. Breeding biology and breeding success
of the Spoon-billed Sandpiper Eurynorhynchus pygmeus.
Russian Journal of Ornithology4:
77–91. (In Russian.)
Zöckler, C., E.E. Syroechkovskiy & P.W. Atkinson. 2010a.
Rapid and continued population decline in the Spoon-billed Sandpiper
Eurynorhynchus pygmeus indicates imminent extinction
unless conservation action is taken. Bird Conservation International20: 95–111.
Zöckler, C., E.E. Syroechkovskiy, Jr. & G. Bunting.
2010b. International Single Species Action Plan for the Conservation
of the Spoon-billed Sandpiper (Eurynorhynchus pygmeus).
Technical Report Series 23. BirdLife International
Asia Division, Tokyo and CMS Secretariat, Bonn.
Kindly
submitted by:
Philip D. ROUND, Department of Biology, Faculty of Science,
Mahidol University, Rama 6 Road, Bangkok 10400 Email: philip.rou@mahidol.ac.th
Krairat EIAM-AMPAI, Wildlife Research Division, Department
of National Parks, Wildlife and Plants Conservation, Phaholyothin
Road,
Chatuchak, Bangkok 10900
Somchai
NIMNUAN, Wildlife Research Division, Department of National
Parks, Wildlife and Plants Conservation, Phaholyothin Road,
Chatuchak, Bangkok 10900
Thiti
SONSA, Wildlife Research Division, Department of National
Parks, Wildlife and Plants Conservation, Phaholyothin Road,
Chatuchak, Bangkok 10900.
Smith SUTIBUT, Bird Conservation Society of Thailand, 221,
Mu 2, Soi Ngamwongwan 2, Bangkhen, Muang District, Nonthaburi
11000.
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Raptor Migration, 26th Oct-5th Nov 2021 -
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Mongolia , 20th May-3rd June 2021 - Black-billed
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Tit, Pallas's Sandgrouse: 
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Raptor Migration, 26th Oct-5th Nov 2021 -
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