| 1 | Java keelback |
A common snake near watery areas of Java. The Java keelback (Fowlea melanzosta) is closely related to the checkered keelback of India (Fowlea piscator), and was originally considered to be one of its subspecies. In 1996 though, it was declared to be independent.
Javan keelbacks are abundant on their namesake island, including near the capital Jakarta. They’re also present on Bali and have very sparse numbers in Sumatra, but aren’t found in Sulawesi, peninsular Malaysia or Borneo. The Java keelback is a flexible species, and will appear anywhere in Java with water. This means marshes, the grassy banks of rivers, lake shores, and especially in rice paddies. Javan spitting cobras also enjoy rice paddies, making it likely that they enjoy Javan keelbacks as a meal.
Javan keelbacks average at 80.5cm long, with the tail comprising 24.8% of the body on average. The maximum ever confirmed length is 120.0cm.
This is a variable snake with two classic morphs: striped and blotched. Some are bright yellow, as shown by this video where a guy holds one in his hand effortlessly, with the keelback staying completely calm. The Javan keelback was also believed to live on India’s Andaman islands, but this turned out to be a different species: Xenochrophis tytleri, AKA the Andaman keelback.
| 2 | Ashy pitviper |
The resident tree-dwelling pitviper of Java, as well as Bali and southern Sumatra. Ashy pitvipers might not be found in central Jakarta itself, but they dutifully guard all the forests surrounding it.
This species generally rests on branches, though not 100% exclusively, and reaches a known maximum of 90.0cm. Ashy pitvipers don’t cause legions of deaths per year, but have a strongly haemorrhagic venom, which acts via pro-coagulant means, activating clotting factors so rapidly that none ultimately remain.
Ashy pitvipers are a highly variable snake in appearance. They’re generally yellow to grey, smattered with many fine spots that give them their “ashy” name. However, males are far more colourful overall, with far more vividly contrasting patterns. The picture above is probably a female, as its colours are more uniform. Occasionally, you can even find purple varieties of the Ashy pitviper.
Ashy pitvipers are recognisable partly by their jutting snout, and a few elevated supraocular scales, giving them the appearance of having eyelashes. Because of these features, and the fact that they’re rarely a clean pastel green, they’re simple to distinguish from Java’s other tree-dwelling pitviper, Trimeresurus insularis (see below).
| 3 | Aplopeltura boa |
One of Java’s most easily recognisable snakes. This is a bizarre snake with an extremely thin body, combined with a highly rounded head, and large eye with round pupils.
Blunt-headed slug snakes (Aplopeltura boa) measure up to 75cm and spend most of their life on branches, hunting for slugs and snails. They suck the latter from shells using specialised jaws, with extra teeth in their right side. Instead of sucking the insides free like spaghetti, like similar snakes, they detach the soft part of a snail’s body from its operculum (shell) using a sawing motion.
This species is widespread, ranging from Thailand in the north, through peninsular Malaysia, Sumatra, and finally to Java, where it’s very common, and not at all hard to find (as well as easy to recognise).
Aplopeltura boa is especially concentrated on the slopes of two Javan volcanoes: Mount Salak and Mount Gede. The former last erupted in 1938, the latter in 1957, but Mount Gede had at least 21 eruptions between 1747 and 1957, with the biggest being in 1840. This spewed a vast amount of pyroclastic flows, though thankfully caused no fatalities. Whether the local Aplopeltura boa populations were affected is a mystery. It’s possible that they saw the lava flows coming, glanced each other, and all retreated to higher branch perches at once. Either way, they’re still there today.
| 4 | Malayan banded wolf snake |
The Lycodon wolf snake genus has 73 members, but the Malayan banded wolf snake is one of the more widespread, ranging from Thailand to Malaysia to Brunei. Java is yet another of its strongholds, from east to west, including near the capital Jakarta. This species is non-venomous and primarily inhabits forest floors, with a maximum length of 100cm. Malayan banded wolf snakes primarily hunt reptiles, such as geckos and tiny skink lizards of the forest.
Lycodon subcinctus is safe to pick up, but extreme caution is advised. This species is a blatant mimic of the severely neurotoxic banded krait (Bungarus candidus), one of Java’s most dangerous snakes, whose bite regularly has lethal consequences (easily more deadly than most pitvipers). The black and white bands are a clear match, as are their forest floor habitats.
There’s one clear difference, as the banded krait tends to have more evenly spaced black-white bands, while in the wolf snake, the black spaces are significantly longer. But if you encounter either, take a step back, just to be sure. Do not engage unless you’re a herpetological expert. A trip to Java can be lethal.
Java is also home to the common wolf snake (Lycodon capunicus), but this tends to be chocolatey brown, overlaid with much messier white patterns rather than simple encircling bands. The two are easy to distinguish.
| 5 | Red pipe snake |
This species is known by two common names: red-tailed pipe snake and red cylinder snake. This is because of their extremely round body in a cross section, the opposite of a US corn snake, which has a completely flat belly to allow it to dig into tree bark while climbing. Red cylinder snakes have a different goal: forging a path through layers of leaf litter covering forest floors.
Red-tailed pipe snakes (Cylindrophis ruffus) measure up to 90cm and are common all over southeast Asia. However, of all their hotspots, Jakarta and its outskirts may have the most dots on the map of amateur sightings.
Red-tailed pipe snakes are also named for their bright red tail which they wiggle to distract enemies when flustered. An iridescent sheen is another of their characteristics. Red-tailed pipe snakes are generally dark with multiple overlapping bands, but in certain individuals these are faded and much harder to spot (though still present). The bands themselves vary from yellow like above to white.
Red-tailed pipe snakes are perfectly safe to pick up, with no venom whatsoever. Most of their diet consists of elongated prey like fellow snakes and eels. While not aquatic, they tend to appear in microhabitats adjacent to water, like the roots of long grass by a river, or moist, waterlogged leaf litter by a forest stream.
| 6 | Orange-bellied snake |
One of Java’s subtlest, stealthiest snakes. You won’t turn a corner and find a hissing orange-bellied snake blocking the entrance to your hotel, which is perfectly possible with a Javan spitting cobra. Orange-bellied snakes range from peninsular Malaysia to Singapore to Sumatra to Java, and aren’t well researched, due to their secretive ways. They lurk on thick forest floors, sometimes straying to grassy clearings adjacent to forests.
This species is a dull brown from above, with occasional snowy white marks. However, their underside is much more colourful. The exact intensity of the belly varies, as in some snakes, it’s a full fiery orange, while in others it’s much paler, like a watered down orange-flavoured ice lolly.
Gongylosoma baliodeira was originally assumed to be nocturnal, until numerous images appeared of it slithering in daylight with a focussed, alert expression. Alongside insects and tiny lizards, this species is confirmed to prey on spiders. Like any snake, it swallows them whole, 8 legs and hairy body, and as it lacks a powerful venom or constricting skills, these spiders are swallowed alive.
| 7 | Eight lined striped kukri snake |
Part of the vicious, ripping, tearing kukri snake clan. The 88 member Oligodon genus lacks any form of venom but does have especially sharp front fangs. The eight-lined striped kukri snake (Oligodon octolineatus) is one of Java’s more flexible species. They happily occupy forests, fields, parks, gardens, woods and suburban areas alike, as long as there’s sufficient vegetation.
When flustered, this species will display the bright, vivid underside of its tail, which is salmon-coloured. This trick is used by a few other members, such as the small-banded kukri snake. Oligodon octolineatus is most common in western Java, and has been found in Jakarta itself. Across southeast Asia, they’re found in Sumatra, Singapore and Malaysia (peninsular and Borneo).
This species is simple to recognise up close because of its namesake lines. The stripe directly down the spine (vertebral stripe) is a bright orange. Adjacent on each side is a vivid black stripe. The next stripe on each side is a pale grey. Though the exact thickness of the parallel stripes varies, the colours are fairly consistent, especially the orange stripes. Oligodon octolineatus only peaks at 68cm, but their bright colours help them to stand out.
Another common species on Java is the brown kukri snake (Oligodon purpurascens). Nobody could confuse the two, as this species has large, irregular brown blotches, instead of neatly ordered parallel stipes. It’s much less colourful, with pale brown set against slightly darker brown.
| 8 | Lesser Sunda pitviper |
Lesser Sunda pitvipers (Trimeresurus insularis) are found across Indonesia’s various Lesser Sunda islands, the largest of which is Bali. They’re particularly common near the Bali capital of Denpasar, but they also have a large presence in the eastern half of Java. This species is famous for being one of the bluest snakes, as while the majority are jungle green, with a white line on their flanks, a sizeable portion are sky blue and remain that way for life.
Trimeresurus insularis is mainly found in forests at altitudes up to 1200 metres. This species is a very imaginative hunter. One of their strategies is to rest on branches directly adjacent to sheer limestone cliff walls, and wait patiently for climbing lizards to run up, and then pluck them off with a sudden extension of their coiled body.
Trimeresurus insularis can ambush prey 5-15 metres high in the tree canopy, but also on vegetation close to the ground. They even possess a brightly coloured tail tip which they move in a slow rhythmical fashion, in order to lure in curious amphibians.
Fortunately, humans are not susceptible to this hypnosis. If a Lesser Sunda pitviper sinks its teeth into you, you can expect swelling, agonising pain and possibly necrosis, but most likely not death. One of their confirmed prey is Boulenger’s pipe snake (Cylindrophis boulengeri). This is related to the red-tailed pipe snake mentioned earlier on this list, so this too may be part of their diet.
| 9 | Striped keelback |
The striped keelback (Xenochrophis vittatus) is a semi-aquatic species of Java, which is common in small streams, ponds and rice paddies. This is a frog and fish-eating species which often appears in backgardens, and sometimes climbs up low vegetation like bushes in its curious quests for food.
This is a harmless snake which has never killed a human. Striped keelbacks are fairly easy to recognise, as they have patterns arranged in parallel stripes running lengthways down its entire body. The most recognisable marking is on its flanks – a series of rapidly alternating black-white markings like teeth or a saw’s blades. Their upper back usually has brown-orange stripes alternating with black.
The striped keelback is found all over Java. Elsewhere, it has a presence in the jungles of Sumatra, and was introduced artificially in Singapore into its Sungei Buloh wetland reserve (a popular bird watching spot). Weirdly, they’ve also been spotted in Puerto Rico, which is their only record in the western hemisphere, and they’re assumed to have escaped from overseas shipping containers in 1994 or earlier.
Striped keelbacks coexist on Java with their relative the triangle keelback (Xenochrophis trianguligerus), but this has totally different patterns, with blotches instead of neat and ordered lines.
| 10 | Linne’s dwarf snake |
Of all snake groups, the Calamaria reed snake genus may be the largest one in proportion to how little research it has. There’s 66 members in Calamaria, but most are shy burrowers and barely understood. The pink-headed reed snake and variable reed snakes are decently understood, and another relatively common (though still shy) member is Linne’s dwarf snake (Calamaria linnaei), found mainly on Java, including near the capital Jakarta.
This is a 30cm snake which appears dark from a distance, but gains complex patterns up close, including an iridescent rainbow sheen at certain angles. Another ID sign is a bright orange underside. Linne’s dwarf snake is often found in coffee and tea plantations, rummaging around in fallen plant matter. They usually appear at higher altitudes of 900 to 1200 metres, but also as low as 200 metres.
The location of this snake? It’s believed to inhabit Java exclusively. Visit Sumatra or Sulawesi, and you will walk thousands of miles with your binoculars and never find one. Little is known about Linne’s dwarf snake’s diet, but earthworms and insects are a high probability.