Sunday, 11 March 2018

NSS Kids’ Fun with Herps at Sungei Buloh Wetland Reserve


Text & Photos by Gloria Seow, Education Committee Vice-Chairperson

We learnt that the young Saltwater Crocodile (see photo) is pale yellow in colour with black stripes and spots, while adults are uniformly brown or grey.

A light rain drummed steadily as we gathered on 18 June 2017. Still, we were hopeful of seeing some of Sungei Buloh Wetland Reserve’s herptiles, given the sharp eyes of our guides the Law brothers Ing Sind and Ingg Thong. They are passionate about herptiles (reptiles and amphibians), and belong to the Herpetological Society of Singapore.

But first, Auntie Gloria presented a crowd pleaser – a colony of Lesser Dog-faced Fruit Bats (Cynopterus brachyotis) roosting under the roof of the Visitor Centre. For many, it was their first encounter with an upside down wild bat trying to catch some sleep. This bat shows sexual dimorphism – males have a rufous collar while females lack this. It can be readily seen flying around housing estates to feed on fruiting trees in the late evenings.

At the main bridge, we spotted our first herptile – a young 2-m long Saltwater Crocodile (Crocodylus porosus) spread out in full glory on the river bank. This raised the excitement level by several notches as we took turns peering through the scope. Ingg Thong remarked that young crocs are pale yellow in colour with black stripes and spots, while adults are uniformly brown or grey. Little Emmanuel then found us a White-breasted Waterhen (Amaurornis phoenicurus) foraging by the mud banks.

Our guide Ingg Thong pointing out a half-submerged Malayan Water Monitor.

Next, we stopped at the Main Hide to gaze out at the wetlands. Few birds were around as it was not yet the migratory season. Nevertheless, we heard the raucous cry of the Collared Kingfisher (Todiramphus chloris) as it flew by, and had fleeting glimpses of the Black-naped Oriole (Oriolus chinensis) up in a tree.

Despite the steady drizzle, we pressed on. While Ing Sind went ahead as spotter, Ingg Thong engaged the children with his wealth of knowledge. Pointing at a Macaranga sapling, Ingg Thong remarked that it has a symbiotic relationship with biting Kerengga ants (Oecophylla smaragdina). The ants make themselves at home in the hollow of the stem and will attack any intruders, hence protecting their host from herbivores. They are in turn rewarded with secretions of nectar. Kids were fascinated to see live examples of this ant-plant symbiosis.

Ingg Thong introduced the Sea Holly (Acanthus ebracteatus), a mangrove shrub with leaves that resemble the festive Christmas Holly. Mangrove plants are adapted to the changing salinity of tidal brackish waters, by extruding salt crystals in their leaves. He drew attention to a Fishtail Palm (Caryota mitis) with a prominent cluster of drooping fruits. When touched, the fruits can cause a terrible itch due to oxalic acid – a prank that children used to play on their teachers by coating surfaces with them. He commented that the plant’s jagged leaves look half-eaten, deterring animals from making a meal of them.

The Malayan Water Monitor is the second largest lizard in the world after the Komodo Dragon.

At the freshwater pond, we found a lone Red-eared Slider (Trachemys scripta elegans) swimming forlornly. This invasive herptile (in this case a turtle) originates from the US. As a popular pet, the slider is sometimes abandoned by owners when it grows big and is no longer cute, and is hence common in waterbodies around Singapore. The pond also held several Malayan Water Monitors (Varanus salvator), another herptile. We observed them swimming languidly around and clambering onto shore. The monitor is the second largest lizard in the world after the Komodo Dragon. Sometimes, it exceeds the dragon in length but is not as heavy. It is often mistaken for a crocodile when half submerged.

We spotted a total of four Saltwater Crocodiles in one morning.




We completed the loop around Buloh to end at the main bridge. Here, we were elated to pick out three submerged crocodiles with only their snouts and eyes visible. A contact told us that he had seen six crocodiles the day before. A recently-discovered crocodile at Pasir Ris beach is likely from Malaysia as the Causeway forms a physical barrier between Sungei Buloh and Pasir Ris. The growing number of crocodiles indicate that Singapore’s watery habitats are in good health.





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