10 No 1
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
10th Anniversary Celebration
Nature and me
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.
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.
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
© Sungei Buloh Wetland Reserve