Update of Kranji Reservoir Adoption Programme (May 2010)

By Dr Ho Hua Chew

Pond Maintenance

Maintenance work for the Marshy and Clearwater ponds, at their landward edges and shallower parts, were continued by volunteers. Twenty River Valley High School students came back for a second time on 31 April 2010 to resume the clearing of unwanted vegetation. This was followed by 16 staff from Bloomberg in May 2010.

Bloomberg staff clearing unwanted vegetation from the bund

Apart from voluntary work, professional contract maintenance was also carried out in May at the deeper ends of both ponds. Aside from clearing the unwanted pond vegetation, workers also opened up a clogged stream that flows into the Marshy Pond and cleared the vegetation at the edge of the small bund dividing the two ponds. The cleared plants were sent once again to Green Circle Eco Farm for composting.

Bird Surveys

Three birdlife surveys were carried out in February and March 2010, with the objective of setting up an inventory of the types and numbers of bird species that can be found at the reservoir’s Intake Bund and at the marshland fringe along the Intake Channel. One survey was conducted in the late afternoon while the other two were done in the morning. The transect was along the two kilometer Intake Bund, which is currently under restricted access controlled by PUB. These surveys will provide ecological information relevant to the issue of opening up the Bund on a free-and-easy basis to visitors, hikers, cyclists etc. We are concerned that the establishment of a park connector along the Bund will disrupt the birdlife that are using these areas for resting and feeding. The surveys recorded 39 species numbering 204 birds in all. These include the Little Tern (endangered), Grey Heron (vulnerable), Purple Heron (endangered), Yellow-billed Egret, Yellow Bittern and Yellow Wagtail. At least 17 Grey Herons were regularly using the Bund proper for resting and fish foraging.

Flock of Grey Herons on Kranji Bund by Ian Rickword

Flock of Grey Herons on Kranji Bund by Gerard Francis

A report based on these surveys, as well as information from recent observations outside the surveys, is in the process of being formulated and will be submitted to the relevant authorities by June 2010.

Kranji Reservoir Adoption Programme Update (April 2010)

By Dr. Ho Hua Chew

Exciting Bird Sightings

After much restoration work to the Kranji Marshes, as part of NSS’ adoption of the Kranji Reservoir, the uncommon Common Moorhen was spotted at the marshy pond on two occasions. Three birds were seen by Leslie Fung on 9 March 2010 and one bird was recorded by myself on 18 March 2010.

Common Moorhen (Tsang KC)

Leslie even observed that one of the moorhens was a juvenile. This is good news as the Common Moorhen, which was supposedly common at one time, is hard to come by nowadays. Bird species that were previously not recorded before the restoration are also making a comeback. These include the Yellow-billed or Intermediate Egret, Yellow Wagtail and Von Schrenck’s Bittern.

The best sighting to date is of 2 Cotton Pygmy Goose seen by Lim Kim Seng on 29 January 2010. The one-off appearance of this rare and critically endangered bird is highly significant as it has not been seen for many years. As one of only two wild duck species in Singapore, the Cotton Pygmy Goose may sadly be headed for local extinction. The challenge is to make the Kranji Marshes attractive to them so that they will continue to survive and make regular appearances. We also await the return of the Lesser Whistling Duck.

Cotton Pygmy Goose (or Cotton Teal) & Whistling Duck

Pond Maintenance

Twenty students from River Valley High School were down at the Marshes on 24 March 2010 to lend their muscles in clearing the overgrown vegetation at the marshy pond. Teacher-in-charge Mr Azmi and NSS Vice-President Leong Kwok Peng were there to coordinate the effort. Work began at 3 pm but after about an hour and a half, it began to pour heavily. Students quickly sought refuge in their nearby school bus, which acted as a rain and lightning shelter. Maintenance work resumed the following week on 31 March 2010 from 3 pm to 6 pm.

These helpful students concentrated their efforts in clearing the dry edges of the marshy pond as well as the shallower portions of the water body. The accumulated mass of vegetation was collected by Green Circle Farm’s Evelyn Lim-Eng and her workers for composting.

This is the first volunteer effort in maintenance of the restored marshy pond. Students enjoyed the backbreaking work despite getting soaked, caked in mud, and scratched by thorny Giant Mimosa shrubs. Somebody even had a leech bite! A dab of Tiger Balm was enough to dislodge the bloodsucker. The Conservation Committee would like to thank River Valley High School students for a job well done.

Kranji Reservoir Adoption Programme Update

By Dr Ho Hua Chew, Coordinator of Kranji Reservoir Adoption Programme, Conservation Committee

One year has elapsed since the launch of NSS’ Kranji Reservoir (Marsh) Adoption under the PUB’s ABC Waters Programme. Much has transpired during this time and here are some updates:

Kranji Nature Walks
Twelve nature walks at Kranji Marsh were conducted for the whole of 2009. Six of these trips were organized for the public as part of our outreach programme; four walks were conducted for NSS members; the remaining two trips were for corporate and social organizations. All trips had an average of 20 participants. The Education Group also held a “Fun at Kranji Marsh” session for 25 NSS Kids and their parents/caregivers, totaling 70 participants in all.

Pond Restoration and Birdlife
The restoration of the large marshy pond was completed in November 2009, which involved the clearing of unwanted vegetation that had overwhelmed the pond for many years. Now, two thirds of this pond comprises open water free of vegetation, with two small low-lying islands created from the dugged-out mud, which also helped deepen some water stretches. Several fallen tree-branches have been planted at strategic points in the pond to serve as bird perches. The smaller open pond has been left alone for the time being.

The big slabs of concrete lining the main track to the ponds were moved to the site of the Seaside Mempari tree (Milletia pinnata), just by the edge of the pond. These concrete slabs now encircle the tree at a safe distance to prevent soil compaction, serving as seats under the tree’s shade where one can enjoy scenic views of the pond and marshy landscape.

The Red-Wattled Lapwing (4 birds) has made a welcome appearance at the new islands created in the pond. Previously, for many years, these birds have avoided the pond area, restricting themselves to the field of the Mediacorp Transmission Station next door. Also new to the pond is an Intermediate Egret that likes to forage at its far end. The Purple Swamphen and Purple Heron, both of which like to lurk in and around the aquatic vegetation, are now easier to spot. Brown Shrikes and Blue-tailed Bee-eaters have been frequently observed at the marshy pond using the planted branches as vantage perches. This pond restoration will be followed by periodic maintenance to prevent aquatic vegetation from overwhelming the open waters again.

Biodiversity Surveys
Continual monitoring of the types of butterflies, dragonflies and birdlife found at Kranji Marsh are periodically carried out. Prior to the implementation of the pond restoration work, we completed an inventory of the plants, birds, dragonflies and butterflies found in and around the edges of the two ponds. Subsequent monitoring will give us a good picture of the results of the pond restoration work.

Rain-shelter and Eco-toilet
The area chosen to site a rain-shelter and eco-toilet comes under the Singapore Land Authority (SLA). This site is at the entrance to the ponds, close to the Kranji Pumping Station. Approval for the rain-shelter was sought from SLA but was not given. For your information, all dry land at the edges of the two ponds fall under the authority of SLA. We are currently using a bus to act as a rain-cum-lightning shelter, as well as to ferry participants to and from our meeting point at Kranji Reservoir Dam Carpark. This has proven to be highly convenient. At present, there is only one Kranji countryside shuttle service to Neo Tiew Lane 2, but the service starts late at 9 am.

Shrub Planting
Shrubs will soon be planted at the small bund dividing the two ponds, stretching one-third of the way from the back end of the ponds. This exercise is meant to attract butterflies and more bird species to the edges of the two ponds. The Bird, Plant and Butterfly Interest Groups will assist in terms of recommending the various shrub species that can be planted.

Acknowledgements
The Conservation Committee would like to thank the following people for helping out in the implementation of the Kranji Reservoir Adoption Programme in its various manifestations (nature walks, pond restoration, biodiversity surveys): Leong Kwok Peng, Michelle Sim, Tay Kheng Soon, Stephen Lau, Gloria Seow, Timothy Pwee, Lena Chow, Angie Ng, Gerard Francis, Joseph Lai, Yap Von Bing, Wong Chung Cheong, Anuj Jain, Allan Teo, Margie Hall, Wing Chong, Lim Kim Chuah, Alan Owyong, Willie Foo, Kenneth Kee, Doreen Ang, Peng Ah Huay, Ian and Freda Rickword, Gan Cheong Weei, Simon Chan, Steven Chong, Tang Hung Bun, Cheong Loong Fah.

Note: This article was also published in Nature News Jan-Feb 2010 issue. It can be downloaded from http://www.nss.org.sg/naturenews.html