Four terrestrial elapid genera are from the Philippines, two of which are cobras (Naja and Ophiophagus) and two others from what has been loosely referred to as “coral snakes” (Calliophis and Hemibungarus). Of these four, Hemibungarus is endemic to the Philippines and of its three currently recognized species, one is the subject of this article: Hemibungarus calligaster.
Did you know?
Ten years before the establishment of the genus Hemibungarus. Albert Gunther moved it to the genus Calliophis (as “Callophis”), and it is under this genus that the species was known for many decades before Hemibungarus was given due recognition, resulting in its resurrection.
Hemibungarus is primarily differentiated from Calliophis by the venom glands which are of normal placement and size in Hemibungarus but which extend to the body cavity in Calliophis.
Taxonomic history
Hemibungarus calligaster was originally described as Elaps calligaster by Arend Friedrich August Wiegmann in 1835 from collections made by F.J.F. Meyen and was transferred to the genus Hemibungarus by Adolf B. Meyer in 1869. Edward Taylor in 1922 said, “The type of locality is probably Manila.”
The accepted name for the snakes from the genus Hemibungarus is “barred (or annulated) coral snakes” but I find this name ambiguous as the vast majority of corals worldwide have annuli or bars as part of their dorsal patterning. My own version would be “black coral snakes” as no other coral snake genus has species that are predominantly black. Using this name thus points automatically to Hemibungarus, though I must admit that the common name I prefer using will get little or no attention from the herpetological scene as a whole.
The Tagalog name is usually “taling-bilao” but this name is also applied to the native Boiga dendrophila subspecies. Years ago, I was informed that in Batangas, another epithet used for these snakes is “palasingsingan,” an obvious reference to the rings. Edward Taylor (1922) added “Camamalu (Pampango)” but noted that it was also “synonymous with tadioco and carasaen; a name applied to Naja naja and Naja hannah; deadly; Casto de Elera says that it is Hemibungarus calligaster.” De Elera was a former professor of Jose Rizal, and whose zoological collections are presently housed at the UST Museum of Arts and Sciences.
Naturally, common names may be confusing as different provinces and regions may have different names for one single snake species. Latin names allow us to speak the same language.
Appearance
Hemibungarus calligaster are small snakes that average a total length of about half a meter. The body is slender and cylindrical in cross-section, with heads that are barely distinct from the neck. The snout is obtusely squarish and the eyes are small. The tail is short and terminates in a mucronate spine that the snake uses when grabbed.
The scales are non-overlapping and smooth. The dorsal color is overlaid with shiny iridescence, black with thin white rings that usually only appear as edgings of black scales instead of entirely white-colored scales. However, close examination reveals that the white rings are really the margins of a broad, inversely triangular black banding that extends to the ventrals. In good light though (and if one’s eyes are sharp enough), one may notice that these black bands are darker than the black ground color. Hemibungarus calligaster therefore, are more accurately defined as black snakes with black bands. In some specimens, the ground coloration is tinged with brown while the scales edged with white are jet-black.
The head is black with the eyes flanked by a pair of short, vertical white stripes and there are a couple of diagonal white stripes running from the neck to the upper jaws but not meeting at the head. In some individuals, the white coloring is obscured by melanin.
The snout is orange to orange-red. The venter is orangish-red with alternating black bands while the tail is orange-red with black rings. Juveniles are much more colorful and fit the coral snake bill better, being red or bright orange with black bands thinly edged with white. However, melanin pigments eventually take over upon maturity, resulting in black snakes banded with black.
Diet
SpecialCoral snakes have gained notoriety for being almost exclusively ophiophagous, with small species from Asia said to prey on typhlophid blind snakes and worm snakes (Calamaria ssp.). My observations from captive snakes during my college years elucidated a clear disinterest in blind snakes although Calamaria, particularly the common C. gervaisii, are taken. This makes sense: blind snakes are nocturnal while Calamaria are diurnal and it is highly unlikely for the day-active H. calligaster to encounter nocturnal typhlophids when they are out foraging for food.
Apart from Calamaria, fossorial skinks from the genus Brachymeles, especially the small B. bonitae and B. boulengeri, might be also taken; both occur sympatrically with H. calligaster. Cannibalism, to the best of my knowledge, has not yet been reported for this species.
If truth be told, much about H. calligaster’s natural history is unknown. No one knows their population densities, reproductive dynamics (breeding period and gestation), and what the juveniles eat. The snakes might really be numerous in their native habitats, but being secretive snakes, they are rarely seen and encounters are often very fleeting.
Ecology
These coral snakes are denizens of forested areas – both primary and secondary – from sea level to ca. 600 meters above sea level (pers. obs.), preferring areas with layers of humus and dense herbaceous vegetation. Some individuals blunder around human settlements in rural areas.
The snake is found throughout the island of Luzon. A closely related species, H. mcclungi, has been recorded from Aurora on the east coast and the island of Polillo, although I have found this species overlapping in range in Laguna. It is not yet known at this point if hybridization events between the two species occur.
Hemibungarus calligaster, despite what most people might think especially for a coral snake, are diurnal snakes.
When I was still a college student, I had the opportunity to keep a few individual snakes at intervals from a number of months to a few years. All were kept in glass aquaria with tight-fitting lids and substrates consisting of soil and leaf mould at an average depth of three centimeters with flat rocks and bark to serve as hiding places and a water bowl filled with fresh water that was changed every two days.
Half of the enclosure was kept moist while the other end was maintained at the dry side. Disturbance was kept to a minimum and cage maintenance was unobtrusive and very quickly done.
All the snakes observed began coming out of their hiding spots at roughly 8AM and the active periods lasted until noon after which the snakes retired again, only for them to come out at about 4PM and burrow again before the sun sets completely. None were found to wander at night.
Active snakes during the day likely explains the killed snakes I sometimes see on mountain trails; these poor serpents would be exponentially less likely hacked to death by fearful humans had they foraged at night instead of during the day. My own experiences with these snakes in their natural habitat also point to these being active during the day.
Temperament
For many people, there is indisputable correlation between a snake’s capability to produce venom and aggression. However, the risks of getting bitten by a ratsnake, for example, is exponentially higher than being chomped by a coral snake.
I have involved myself in a few discussions regarding these snakes’ supposed risk to humans in social media, and this is spurred by suppositions that like all venomous snakes, these coral snakes must also be dangerous. From here, it must be acknowledged that the venom may indeed be dangerously potent, although no one really knows for sure; the bandy-bandy (Vermicella annulata), an Australian coral snake with alternating white and black bands, has weak venom that consequently is not regarded as dangerous, and any generalization about snake venom would be downright foolish.
Nevertheless, one must keep in mind that the snake will have to bite first before the likelihood of envenomation presents itself.
Defensive mimicry
From my own experiences handling these snakes, I can say that the defensive repertoire of Hemibungarus mainly involves a flight response. If it cannot get away for some reason, the snake flattens its tail and curls it upward in a behavior termed “defensive mimicry” wherein the tail tries to attract attention in an effort to protect the much more vulnerable head. In some coral snake species around the world, the flattening of the tail mimics the head. If the snakes are grabbed, they empty out their cloacal musk and try to jab the stiff and very pointed tail tips to the offending fingers, coupled by audible hissing as the snake tries to flail in every direction.
I have not seen one that tried to bite, although to the eyes of the uninitiated, the thrashing and the hissing constitutes an attack. But to put things in perspective, allow me to illustrate this: These are non-aggressive snakes with practically no predisposition to bite. Even if a snake bites, the small jaws are incapable of gaining hold on any human anatomy with the possible exception of fingers – which is another way of saying that picking one up isn’t exactly a bright idea unless you know what you are doing.
Even if a snake manages to gain a grip, the fangs are too small and short to puncture past the epidermal layer, and for venom to be of effect, it has to enter the bloodstream.
These are a lot of ifs. I really don’t think that those people who espouse the idea of these snakes being dangerous to humans have actually observed and handled a number of individual snakes spanning many years. Still, I would never recommend free handling these snakes.
Venomous or not?
While the chances of getting bit may be negligible, the fact remains that all animals, even within the same species, demonstrate individual variations when it comes to temperament. While most may show no inclination to bite, there will always be that individual that sticks out from the rest. Besides, these are still venomous snakes that demand a great deal of respect.
I illustrated above the very minuscule chances of these animals being of medical significance to people, but who wants to prove me wrong by actually putting themselves in harm’s way? Even seasoned herpetologists and herpetoculturists have been tagged by snakes they thought would never have a bad day.
So, my full set of instructions for handling H. calligaster for novices is this: Don’t. If you see one along a trail, leave it be. Take only photos if you can, but if the opportunity won’t present itself, then be gratified seeing one of this country’s most beautiful and enigmatic snakes.
You might want to read:
– World’s deadliest: Meet five of the world’s most venomous snakes
– A historical record of snakes from Manila
– Robert Irwin gets bitten by a snake, poses for a photo afterwards
