It’s World Snake Day today. Here are some unfortunate roadkills I’ve found.

Upper Left: Striped Kukri Snake (Oligodon octolineatus) @ Island Club Road
Upper Right: Paradise Tree Snake (Chrysopelea paradisi) @ Neo Tiew Crescent
Lower Left: Oriental Whip Snake (Ahaetulla prasina) @ Punggol Road
Lower Right: Reticulated Python (Malayopython reticulatus) @ Lim Chu Kang Lane 6F

Today (16th July) is World Snake Day! Here’s a selection of dead snakes I’ve encountered over the years here in Singapore. Most of these were roadkills, while a few were found on the Rail Corridor, back when the tracks were still in place and the trains were in operation along that stretch

Top Row (L-R): Paradise Tree Snake (Chrysopelea paradisi) @ Kranji, Painted Bronzeback (Dendrelaphis pictus) @ Kranji, Oriental Whip Snake (Ahaetulla prasina) @ Sungei Buloh

Middle Row (L-R): Striped Keelback (Xenochrophis vittatus) @ Sungei Buloh, Striped Kukri Snake (Oligodon octolineatus) @ Island Club Road, White-spotted Slug Snake (Pareas margaritophorus) @ Punggol

Bottom Row (L-R): Reticulated Python (Malayopython reticulatus) @ Bukit Merah, Common Wolf Snake (Lycodon capucinus) @ Choa Chu Kang, Equatorial Spitting Cobra (Naja sumatrana) @ Woodlands

Oriental Whip Snake (Ahaetulla prasina)
Punggol, 14th October 2014

This Oriental Whip Snake appears to have been yet another casualty along a road where vehicles are known to travel at high speeds, with very little regard for wildlife.

Just so happened that yesterday (16th July) was World Snake Day, so here’s a selection of snake species found in Singapore:

Top Row (L-R)

Reticulated Python (Malayopython reticulatus):
This is the world’s longest snake, capable of growing to 9 metres in length, although most individuals never attain such sizes. Larger snakes supposedly exist, but these reports are usually wild exaggerations or otherwise difficult to verify. This is one of the most common snakes encountered in Singapore, due to its ability to survive in urban environments. Reticulated Pythons can be found in all sorts of habitats, from forests and scrubland, to neighbourhood parks, monsoon canals, and urban sewers. A row of pits in the scales that line the upper jaw enables the python to sense heat, allowing it to track warm-blooded prey and strike accurately in the darkness. Pythons have long, sharp teeth which curve backwards, making it difficult for a prey animal to break free, which makes up for the serpent’s lack of venom. Pythons kill their prey using constriction, coiling around it until the victim is incapable of breathing and asphyxiates. Rats are a favoured prey, which is why pythons do so well in urban Singapore, and in the past, pythons were infamous as poultry thieves. The larger the python, the larger the prey it can consume; adult pythons are fully capable of taking down cats, dogs, and monkeys, while truly large (and greedy!) pythons elsewhere are known to swallow large mammals such as goats and pigs. Large pythons can be dangerous – humans are typically too large to be seen as prey, but a python that is provoked often defends itself by biting and coiling around an aggressor, and may inadvertently kill the person that it perceives to be attacking it. However, such incidents are very rare; even large Reticulated Pythons usually choose to flee if possible, striking only if cornered. A female python guards her eggs, coiling around them and waiting until they hatch. During this time, she will not feed at all. She even incubates them by ‘shivering’, raising her own body temperature (and the temperature of the eggs) above that of her immediate surroundings.

Oriental Whip Snake (Ahaetulla prasina):
This long, slender snake is often encountered in trees and shrubs along forest edges and in parks and gardens. Its slender body enables it to venture onto the thinnest twigs as it hunts for its prey, usually geckos and other arboreal lizards, and the bright green coloration provides excellent camouflage amongst the vegetation. The Oriental Whip Snake has good binocular vision, and oddly enough, its eyes possess horizontal, keyhole-shaped pupils. This snake has small fangs at the rear of its mouth and is mildly venomous, but it is inoffensive, and usually quickly slithers off if threatened.

Paradise Tree Snake (Chrysopelea paradisi):
Like the Oriental Whip Snake, the Paradise Tree Snake is a diurnal, arboreal hunter that can be commonly found not just in forested areas, but also in suburban and urban green spaces. It hunts geckos, frogs, and sometimes small birds and bats, immobilising its small prey with venom delivered via small fangs at the rear of its upper jaw. It has an interesting adaptation – it belongs to a group of Southeast Asian snakes that can actually glide! By leaping off tall trees, and flattening out its underside into a concave shape while undulating its body as if it’s swimming through the air, the Paradise Tree Snake generates air resistance and lift. In this manner, this species of snake can glide up to 100 metres to another tree, although this tends to end with a not so graceful crash landing. This enables the Paradise Tree Snake to travel easily from tree to tree without spending all the energy on climbing, or risking an attack from predators on the ground.

Bottom Row (L-R)

Twin-barred Tree Snake (Chrysopelea pelias):
Red with black-edged white bars, this is a beautifully patterned snake that is rarely seen. It is mostly restricted to forests in and around the Bukit Timah Nature Reserve and Central Catchment Area. Like its close relative the Paradise Tree Snake, the smaller Twin-barred Tree Snake has the ability to glide from tree to tree. It too is mild-tempered and unlikely to bite, reserving its venom for subduing prey such as geckos and other arboreal lizards.

Wagler’s Pit Viper (Tropidolaemus wagleri):
Also known as the Temple Viper, this is the snake commonly seen at the famous Snake Temple in Penang. In Singapore, however, this is a forest-dependent species that is mostly found in the Bukit Timah Nature Reserve and Central Catchment Area. Almost wholly arboreal, this snake is mostly likely to be found coiled up amongst the branches in low shrubs and trees, anchoring itself with its prehensile tail. Interestingly enough, this species has sexual dimorphism; adult females have different colour patterns from adult males (this specimen is an adult female). Unlike other snake species, which can be found actively slithering about in search of prey, Wagler’s Pit Viper is quite sedentary, and can be often found on the same branch for days. This is a member of the group known as pit vipers, which possess a special heat-sensing pit between the eye and nostril on both sides of the head. Like in pythons, these pits enable the viper to sense warm-blooded prey such as rodents and birds, although geckos may also be taken. A sit-and-wait predator, Wagler’s Pit Viper simply waits for prey to wander within striking range. Vipers have fangs that fold back when not in use, but swing forward to deliver the venom when the snake bites into something. Viper venom is predominantly haemotoxic, and can destroy red blood cells, disrupt the blood’s ability to clot, and cause general tissue damage. Unlike many other Asian viper species, Wagler’s Pit Viper is not aggressive, and its venom is considered to be less potent, with most bites resulting in pain and localised swelling. Getting bitten by one certainly warrants immediate medical attention, but you’re not in great danger of dying.

Blue Malayan Coral Snake (Calliophis bivirgatus):
This is another beautiful forest species, but one that is best admired from a distance. Sometimes seen crossing forest trails or slithering across the forest floor, this snake specialises in hunting other snakes! When confronted, the Blue Malayan Coral Snake may flip over onto its back, flashing its red underside, or hide its head in the leaf litter or under one of its coils while flicking its bright red tail as a distraction. However, despite such a timid nature, it is certainly not to be messed with. The bright red head, tail, and belly, and the bright blue flank stripes make this a highly visible creature at close range, and it is likely that this serves as a warning to potential predators – attacking this snake might prove to be a costly and fatal mistake. A member of the family of front-fanged venomous snakes known as elapids, the Blue Malayan Coral Snake counts other highly venomous snakes such as cobras, kraits, and sea snakes as among its close relatives. Its venom is neurotoxic, with victims suffering from numbness and paralysis, and subsequently respiratory failure as the nervous system shuts down. In fact, another forest snake, the Pink-headed Reed Snake (Calamaria schlegeli), is thought to defend itself from predators by having a similar colour pattern, and hence mimicking the truly lethal Blue Malayan Coral Snake, despite not having any venom at all.

These were some of the many specimens featured at the recently concluded Festival of Biodiversity 2014, which was held at VivoCity last weekend.

Fig. 3. Remains of the partially eaten Oriental Whip Snake (Ahaetulla prasina) (ZRC 2.7057). Photograph by Noel Thomas

Crested Serpent Eagle (Spilornis cheela) preying on Oriental Whip Snake (Ahaetulla prasina)

Location, date and time: Singapore Island, Singapore Botanic Gardens; 14 March 2014; 1220 hrs.

Observation: At 1220 hrs, a Crested Serpent Eagle was observed landing on a grassy slope with an Oriental Whip Snake in its talons. The snake was still alive and writhing. The eagle first bit the back of the snake’s head, presumably killing the prey. It then proceeded to feed on selected parts of the snake while grasping it firmly in its talons. At 1501 hrs in the same area, the snake was found partially eaten and abandoned. It was retrieved for documentation purposes. Injuries were found mostly on the posterior ventral side of the snake. The specimen was then deposited in the Raffles Museum of Biodiversity Research at the National University of Singapore, under catalogue number ZRC 2.7057.

Remarks: The Crested Serpent Eagle occurs in Singapore both as a very rare resident and a non-breeding visitor from neighbouring areas. It is found mainly in forest and old plantations, and is a well-known predator of reptiles, particularly tree snakes (Yong et al., 2013: 36).

Reference:

  • Yong D. L., K. C. Lim & T. K. Lee, 2013. A Naturalist’s Guide to the Birds of Singapore. John Beaufoy Publishing Limited, Oxford, England. 176 pp.

Source: Singapore Biodiversity Records 2014: 82-83

Oriental Whip Snake (Ahaetulla prasina)
Sungei Buloh, 9th January 2014

This unfortunate Oriental Whip Snake was run over by a passing motor vehicle.

Oriental Whip Snake

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Oriental Whip Snake (Ahaetulla prasina)
Woodlands, 27th June 2011

This amputated tail of a snake on the KTM railway line that runs through Woodlands most probably belongs to an Oriental Whip Snake, and was probably the result of an unfortunate accident with a passing train. I searched the surrounding area, but could not find the rest of the snake.

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