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Vol 10 No 1
Feb 2004
A journey
through 2003
Experience of
a lifetime
International Shorebirds Experts meet
Bird RInging in the
Reserve 2002
Birds in the Wetland Reserves
An Uncensored Census at Sungei
Buloh
Kranji Nature Trail
A green corridor
Protected Area Wetland Management Course 6-15 Nov
Sungei Buloh
10th Anniversary Celebration
Nature and me
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Bird Ringing
in Sungei Buloh Wetland Reserve in 2002
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James Gan
senior
conservation officer
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Main article | Table 1 (summary) | Table 2 (longevity)
 Bird ringing has been
conducted at Sungei Buloh
Wetland Reserve (SBWR) since 1990. This article serves to give an overview of
some of the results of the bird ringing efforts at SBWR over the past year.
In 2002, a total of 595 birds from 59 species were ringed.
The ringing field work was carried out on scheduled days and nights
throughout the year. A summary of the number of birds ringed in 2002 (and the
previous two years) is provided in Table 1.
 The most commonly ringed
bird species were (numbers ringed in brackets) :
Common Redshank (72), Javan Munia
(60), Pacific Golden Plover (52) and Marsh Sandpiper (48). Compared to the
previous year’s (2001) results, the number of birds ringed has decreased
markedly.
It is not clear why this is so although the decrease may be partly attributed
to fewer productive hours of mist netting. Large percentage decreases for
birds ringed over the previous years were noted for Curlew Sandpiper, Common
Sandpiper, Whimbrel and Mongolian Plover.
Regular bird counts in SBWR have revealed no significant changes in shorebird
numbers except for the Mongolian Plover. Counts of Mongolian Plover in SBWR
in 2002 peaked at 361 (786 in 2001) during the northward migration and 274
(675 in 2001) during the southward migration.
An explanation for the apparent decrease in Mongolian Plover numbers is
offered. Shorebird counts in the West Johore Straits during high tide have
revealed large flocks (600 on 3 Jan 03) of Mongolian Plovers and much smaller
numbers of Pacific Golden Plovers roosting on the pontoons of off-shore
floating fish farms.
This phenomenon is apparently new. Why these plovers have chosen to roost on
the floating pontoons over the mudflats at SBWR in 2002 is a possible subject
for investigation.
The counts, however, do not suggest cause for alarm with regards to shorebird
numbers for the area. Ringing and shorebird census efforts over the next few
years will help to establish if this phenomenon should be of concern. In
general, though, the retrap/ringing percentages for
those shorebird species have remained steady.
While the absolute number of birds ringed has decreased, 2002 saw some
spectacular species ringed and recorded for the first time in SBWR. They are
the Blue-eared Kingfisher, Brown-chested Jungle-Flycatcher, Streaked Bulbul
and White-rumped Shama.
The checklist (of records dating back to 1987) of wild bird species for SBWR
now stands at 210 species (as at Dec 31, 2002). With the mist netting of the
Blue-eared Kingfisher, SBWR is the only site in Singapore with records of all
eight species of native kingfishers over the past 5 years. All eight species
have been ringed at SBWR. The other new records are also notable. The
Streaked Bulbul is the second record for Singapore and the Brown-chested
Jungle-Flycatcher is a globally threatened species that is at risk of global
extinction. The White-rumped Shama
is of uncertain status. Likely an escapee, it could also be a wild bird from
forest areas near SBWR. Its uncertain status means that it has not been
included in the checklist at this point in time.
A bird species ringed for the first time (it had been recorded visually
previously) in SBWR is the Striped Tit-Babbler. Three individuals were
ringed. Other interesting birds ringed in 2002 were the Asian Paradise
Flycatcher, Forest Wagtail, Red-necked Stint and the Siberian Blue Robin. The
mist netting effort has continued to bear fruit with an increase in the retrap rate over the previous two years. The retrap rate has increased steadily from 4.5% in 2000 to
11.0% in 2001 and 14.3% in 2002. In 2002, 694 individual birds were caught of
which 99 were retraps of birds from 31 species for
birds that were ringed before 2002. This compares favourably to 1127
individual birds caught of which 124 were retraps
from 31 species in 2001.
The leader for the past two years, the Common Redshank with 13 retraps in 2002, has relinquished its lead. The Collared
Kingfisher has wrested the pole position with 16 retraps.
The species in third and fourth position are the Pacific Golden Plover and
the Yellow-vented Bulbul with eight recaptures each. One use for the data
obtained from retrapped birds is the enabling of
longevity records and the survival of bird species to be determined. These
records are provided in Table 2. Of special mention, a Pacific Golden Plover
was recaptured after an interval of 108 months (9 years). This individual is
believed to be the oldest ringed Pacific Golden Plover in the world!
One Black-capped Kingfisher exhibited high site fidelity. The individual that
was reported mist netted at the same net after an absence of one season in
the bird ringing report for 2000 was mist netted on 9 Jan 02. A Black Bittern
was recaptured in January at the same wintering area 13 months after it was
ringed at the freshwater ponds. Similarly, a Yellow Bittern was recaptured in
October, 23 months after it was first ringed. These recaptures suggest that
the wetland reserve is a wintering area for these species.
Other interesting recaptures include the Common Kingfisher, Brown Shrike and
Oriental Reed Warbler. This is the first time that SBWR has recorded the
return of these migrants back to their ringing site. Some movements of birds
were noted within the wetland. Notably, a Collared Scops
Owl that was ringed at the western end was netted in the Visitor Centre area
at the eastern end. Similar movements were also noted for a Stork-billed
Kingfisher.
In summary, bird ringing in 2002 has continued to reveal surprises in the
presence of bird species, their movements, abundance and survival. The data
collected are invaluable for the long-term conservation management of the
wetland reserve.
Acknowledgements
This article is possible because of the field studies supported by NParks. Thanks to fellow ringers Ramakrishnan,
Linda Goh, Charles Lim, Patricia Phua, Ray Knock, Mustaffa
Bin Hajar, Abdul Khalid and Chan Su Hooi for
contributing to the ringing work. Ray, in particular, shared his extensive
experience in ringing which we benefitted. Many others assisted with the
ringing activities including staff, volunteers and friends especially Halilah
Ahmad and Ong Hai Chwee. Joseph Lai helped to key
in some of the records. In addition I am grateful for the voluntary help from
Nick Baker, Richard O’Keefe, Debby Ng, Lua Wai Heng and Adeline Chia.
Kenneth Kee, and R. Subaraj who gave expert
advice and contributed some sighting and observation records.
References
Piersma. T. & Wiersma,
P., (1996). Family Charadriidae (Plovers). Pp.
384-442 in: del Hoyo,J.,Elliot,
A. & Sargatal, J. eds
(1996). Handbook of the Birds of the World. Vol. 3.
Hoatzin to Auks. Lynx Edicions, Barcelona
Wells, D. R. 1999. The Birds of the Thai-Malay Peninsula, Vol
1. Academic Press, San Diego
Wetlands Vol 8, No.1, April 2001, Bird Ringing in Sungei Buloh Nature Park in
2000,. Pp 7 –10, Publication of SBNP, National Parks
Board, Singapore
Wetlands Vol 9, No.1, April 2002, Bird Ringing in Sungei Buloh Wetland Reserve in
2001,. Pp 8 –11, Publication of SBWR, National Parks Board, Singapore
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