Recognizing Deadly Venomous Snakes from Harmless Snakes of Sri Lanka

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Front Cover:
Chrysopelea ornata (Ornate flying snake (E); Pol mal karawala,
Malsara, Panina karawala (S))
One of the most vibrantly coloured snakes in Sri Lanka that
has been aptly named Malsara (u,aird) which in Sinhalese
means ‘cupid’. Unfortunately this harmless snake has become an
innocent victim owing to its colouration (red, black, and yellow),
which symbolise ‘danger’ in the animal world. Commonly found
in the canopy of tall trees of the wet zone, this is a rare species
in the drier parts of the island. Humans living on the periphery
of forests are likely to encounter them more often, as they will
come to feed on geckoes commonly found in human settlements,
and unfortunately when they do, they are often killed due to
misplaced fears.
Back Cover:
Left to Right Python molurus (Rock python), Echis carinatus
(Saw scaled viper), Eryx conicus (Sand boa)
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Citation
Wickramasinghe, L. J. Mendis (2014). Recognising Deadly Venomous Snakes from
Harmless Snakes of Sri Lanka. Colombo, Sri Lanka: Ceylon Tea Services PLC.
Text & Photographs by
L.J. Mendis Wickramasinghe
Assisted by
Nethu Wickramasinghe, Dulan Ranga Vidanapathirana
and Gayan Chathuranga
Design and Layout by
Kasun Pradeepa. Wild Studio
ISBN: 978-955-0081-12-7
Ceylon Tea Services PLC
MJF Group
111, Negombo Road
Peliyagoda
Sri Lanka
Contact
info@dilmahconservation.org
January 2014.
Recognising
Deadly Venomous
SNAKES
from Harmless Snakes
of Sri Lanka
Printed and bound
Karunaratne & Sons (Pvt)Ltd.
Authored by
L. J. Mendis Wickramasinghe
Advised by Channa Bambaradeniya, Ph.D.
& Gernot Vogel, Ph.D.
Edited by Devaka Weerakoon Ph.D.

Message from the Founder
An unfortunate fear and loathing of snakes permeates through our society, and
since childhood, I too have been no exception to this disappointing lapse. It is sadly
commonplace for those who encounter snakes to attempt to kill them, owing to
suspicions they harbour that all snakes are poisonous or deadly.
I have learned that these misconceptions which cause panic and revulsion stems
from a poor understanding of snakes and their habits, coupled with the inability and
unwillingness to distinguish between different species of snakes. This results in the
thoughtless killing of snakes, even though many types found in Sri Lanka are largely
harmless and do not attack unless threatened. I have also observed that this has proved
to be a particular challenge within the plantation sector, and tea estates must be no
exception for efforts in biodiversity conservation.
Mr. L. J. Mendis Wickramasinghe has compiled a comprehensive illustrated field guide
on behalf of Dilmah Conservation, which not only seeks to help readers easily identify
snakes so that they will be able to deal with these creatures safely and considerately,
but cultivate an interest and appreciation for the vital ecological role they play in
pest control. It is my wish that this field guide will spark the curiosity of students in
particular, and motivates them to pursue further learning and contribute towards the
study and conservation of reptiles in Sri Lanka.
I firmly believe that it is the duty of Dilmah Conservation to strengthen its commitment
to promoting socially and environmentally conscious educational initiatives towards
fostering awareness, appreciation and respect for Sri Lanka’s natural wealth. Thus, I
am confident that this publication ‘Recognising Deadly Venomous Snakes from Harmless
Snakes of Sri Lanka’ will mark a small but noteworthy contribution by Dilmah
Conservation towards bridging the gaps in knowledge about snakes, minimising
damaging misconceptions and thereby enabling their conservation by helping a broad
audience improve their understanding.
Merrill J. Fernando
Founder – Dilmah Conservation

Recognising
Deadly Venomous
SNAKES
from Harmless Snakes
of Sri Lanka
Authored by
L. J. Mendis Wickramasinghe
Advised by Channa Bambaradeniya, Ph.D.
& Gernot Vogel, Ph.D.
Edited by Devaka Weerakoon Ph.D.

Foreword
Preface
08
Snakes are often considered deadly and dangerous and therefore persecuted
by humans like no other group of animals. Yet snakes are an important part
of natural and manmade ecosystems as they prey on many species that we
consider as pests and help to keep their populations under control. One of
the biggest threats to snakes today is inadvertent killing by humans. Much of
these killings result due to our widespread fear and loathing towards snakes,
as well as great deal of misinformation and misconceptions regarding them.
In Sri Lanka, as this book clearly indicates, only 21 out of the 102 recorded
species of snakes are deadly poisonous. Out of these only 5 species are
known to cause fatalities in humans. Therefore, most of the snakes that we
encounter in life are likely to be harmless. Further, snakes do not ordinarily
attack humans unless provoked, startled or injured. Therefore, we can avoid
the inadvertent killing of these useful creatures by becoming more aware
about them. One important aspect of awareness is to develop an ability to
identify poisonous snakes. This will not only help save snakes but will also
be useful to save the life of a person bitten by a snake, as it is important to
establish the identity of the snake before providing treatment to the snake
bite victim. Identification of snakes is not a difficult task as most poisonous
snakes show characteristic colour and scale patterns that will enable correct
identification. However, many non poisonous snakes tend to mimic the
colour patterns shown by poisonous species as a form of defense from their
predators. As this is a trait that has evolved to confuse their predators it is not
surprising that we too would be confused by this, which in this case is not
working towards their favor. This book attempts to educate the reader about
the value of snakes as well as how to differentiate poisonous snakes from non
poisonous species. I am sure this book will help the reader to lessen their fear
and hatred towards snakes while at the same time develop an appreciation
and respect for their role in our ecosystems.
Prof. Devaka Weerakoon
Department of Zoology,
University of Colombo
Snakes are a group of animals which have been especially revered in the Sri
Lankan context. According to ‘Deepawamsa’, an ancient chronicle of Sri Lanka,
the ‘Naga (Snake)’ people, one of the four powerful tribes in Sri Lanka who
ruled the Northern and Western parts of the Island during the 6th century BC to
3rd century BC, were snake worshippers. King Buddhadasa, the only monarch
known to not only possess the skills of a physician and a surgeon, but also those
of a veterinarian, was fabled to have treated a sick cobra as far back as 340-
368 AD, revealing how compassionate ancient people were towards snakes. The
ruins of the ancient cities also speak of the harmony between snakes and the
people of Sri Lanka. These include guard-stones with a cobra-king providing
protection to the premises, and seven hooded cobra statues built to protect the
tanks constructed by the ancient Kings. However, changing times and four
centuries of colonization have resulted in these ancient traditions being replaced
by a lack of tolerance towards snakes. Like in the rest of the world, snakes have
now become a feared group of animals in Sri Lanka.
The feeling of fear evoked by snakes coupled with an inherent reaction of
disgust often results in attempts to kill snakes. This fear could be justified when
considering the number of deaths caused annually by poisonous snakes. Further,
superstitions and misconceptions also play a significant role in vilifying these
creatures.
In reality, only few species of snakes can actually
cause harm to people. Further, many snakes play
a beneficial role in both natural and manmade
ecosystems, as the natural enemies of many
species who can otherwise undergo a massive
population growth and become pests to man.
Therefore, humans must find a way to co-exist
with snakes on this limited land we have. As such,
we must become aware of how to co-exist. This
book intends to provide the reader with a broad
overview about snakes in Sri Lanka, with special
emphasis on deadly poisonous snakes, and their
identification.
Ruins of a seven hooded cobra, protecting the water near
Urusita Wewa, Embilipitiya

Contents
10
Acknowledgements
This book was made possible thanks to Dilmah Conservation, who invited
me to write a simple guide for the general public to identify venomous snakes
in Sri Lanka. The fieldwork was made possible thanks to the Biodiversity
Secretariat of the Ministry of Environment who provided funds and the
Department of Wildlife Conservation who provided the permit to conduct
the research work. My heartfelt appreciation goes to Mr. Dulan Ranga
Vidanapathirana and Mr. Gayan Chathuranga for assisting me while
photographing and handling the snakes in the field. I would also like to thank
Dr. Channa Bambaradeniya for his valuable comments and my colleagues at
the Herpetological Foundation of Sri Lanka (HFS), for various courtesies. I
wish to thank Dr. Gernot Vogel whose invaluable comments undoubtedly
improved the quality of this book. I would also wish to extend my gratitude
to Prof. Devaka Weerakoon for the valuable time and effort he took to edit
the text to its final form in which it is presented here. Last but not least to my
dear wife Nethu, for her commitment to making this a success!
Foreword .................................................................................................... 8
Preface ........................................................................................................ 9
Acknowledgements ..................................................................................... 10
1. Snakes of Sri Lanka ..................................................................................... 12
1.1 Snake bites in Sri Lanka ....................................................................... 16
2. What is a Snake? ........................................................................................ 17
3. Identification of Venomous snakes ............................................................... 20
3.1 Mimicry ........................................................................................... 20
4. Kraits .......................................................................................................... 24
4.1 Bungarus caeruleus (Thel karawala/ Indian krait) ................................. 26
4.2 Non venomous species that mimic the Indian Krait ............................... 28
4.2.1 Lycodon aulicus (Alu radanakaya/ Wolf snake, House snake) .............. 28
4.2.2 Lycodon osmanhilli (Mal radanakaya/ Flowery wolf snake) ................. 30
4.2.3 Lycodon striatus (Kabara radanakaya/ Shaw’s wolf snake) ................... 31
4.3 Bungarus ceylonicus (Mudu karawala/ Sri Lankan krait) ...................... 33
4.4 Non venomous species that mimic the Sri Lankan Krait ...................... 35
4.4.1 Cercaspis carinata (Dhara radanakaya/ Sri Lanka wolf snake) ............. 35
4.4.2 Dryocalamus nympha (Geta radanakaya, Geta karawala/ Bridal snake) 37
4.4.3 Dryocalamus gracilis (Meegata radanakaya/ Scarce bridal snake) ......... 38
5. Vipers ........................................................................................................ 39
5.1 Daboia russelii (Thith polanga/ Russell’s viper) ..................................... 40
5.2 Non venomous species that mimic the Russell’s viper ............................ 42
5.2.1 Eryx conicus (Wali pimbura, Kota pimbura / Sand boa) ..................... 42
5.2.2 Python molurus (Dara pimbura, Ran pimbura/ Rock python) ........... 44
5.3. Echis carinatus (Wali polanga/ Saw scaled viper) .................................. 46
5.4. Non venomous species that mimic the Saw scaled viper ......................... 48
5.4.1 Boiga triginata (Garandi mapila, Ran mapila, .................................. 48
Kaeta mapila/ Gamma cat snake)
6. Cobra ......................................................................................................... 50
6.1 Naja naja (Naya or Nagaya/ Indian cobra, Spectacled cobra) ................ 50
Literature cited ................................................................................................. 53

1. Snakes of Sri Lanka
Sri Lankan snake fauna comprise of 102 species belonging to 10 families 1-4 .
Out of these 102 species, 87 live on land, 14 live in the ocean, and the
remaining one inhabits brackish water. Nearly 49% (50 species) of the
snake species found in Sri Lanka are endemic to the island, or do not occur
naturally anywhere else in the world 5 .
Trimeresurus trigonocephalus (Green pit viper (E); Pala polanga (S)).
Left: An Enhydrina schistosa (Hook nose sea snake (E); Valakkadiya (S)) killed by fishermen.
Right: A close up image showing the typical flat tail of sea snakes.
12
The snakes of Sri Lanka can be categorized into four groups, depending on
the lethality of their venom. Accordingly, 21 species can be considered as
deadly venomous; five species as moderately venomous and 12 species as
mildly venomous. The remaining 64 species are non-venomous 1-4, 6-10 . This
demonstrates that the majority of snake species (63%) are in fact, harmless.
Members of the genus Boiga (Cat snakes (E); Mapila (S)), one of the most
feared snakes, belong to the mildly venomous group, and its bite causes much
less pain than one inflicted by a hypodermic needle. Moderately venomous
snakes include four species of the genus Hypnale (Hump-nosed vipers (E);
Kunakatuwa (S)), and Trimeresurus trigonocephalus (Green pit viper (E); Pala
polanga (S)). Their bites will result in harmful effects such as gangrene,
necrosis, tissue damage, kidney failure, blisters etc. Hypnale hypnale, which
was previously known to be a moderately venomous snake 11 has now been
classified as a deadly venomous snake 12-16 .
Left: Hypnale hypnale (Hump nosed viper (E); Kunakatuwa/ Mukalang thelissa (S).
Right: Close-up of the head showing the typical posture of hump nosed vipers,
keeps their head slightly angled approximately at 45º.

Likewise, Echis carinatus (Saw-scaled viper (E); Vali polonga (S)) is restricted to
the dry and arid zones of the island. Moreover, as the snake is very small in size
(30 cm SVL), the amount of venom excreted in a single bite is very small 17 .
Left: Hypnale zara (Zara’s hump nosed viper (E); Pahatharata thelissa (S)).
Right: Close-up of the head showing its pointed snout/ rostral appendage, which is
the most relible identification character for all hump nosed vipers in common.
Calliophis melanurus (Sri Lanka coral snake (E); Depath kaluwa (S)).
A very small snake similar in size to an ink tube of a carbon pen.
14
Left: Hypnale nepa (Merrem’s hump-nosed viper (E); Mukalan thelissa/
Mukalang kunakatuwa(S)) Right: Close-up of the head.
Out of the 21 species of snakes considered to be deadly poisonous, fourteen
are sea snakes. These sea snakes are non-aggressive in nature, and since they
are found only in deep waters they hardly interact with humans. Out of the
remaining seven deadly poisonous species, two are coral snakes (Calliophis
melanurus and Calliophis haematoetron) incapable of inflicting damage to
humans owing to their small size (SVL, 30 cm). Out of the five species
remaining, Bungarus ceylonicus (Ceylon krait (E); Mudu karawala (S)), is
non-aggressive in nature and is to some extent an uncommon species.
Therefore in Sri Lanka, the majority of human deaths occur as a result of lethal
snake bites caused by the 3 remaining species of deadly poisonous snakes:
Bungarus caeruleus, (Indian krait (E); Thel karawala (S)), Naja naja, (Indian
cobra (E); Nagaya (S)), and Daboia russelii (Russell’s viper (E); Thith polanga
(S)) 14, 16, 18-19 .
Due to the lack of understanding of snakes in Sri Lanka, they are frequently
killed regardless of their identity. Therefore, the ability to identify at least these
three species will save the lives of human beings and a vast number of innocent
and beneficial snakes. Therefore, the primary aim of this book is to help the
reader to correctly identify life-threatening species, and thereby prevent the
futile killing of a large proportion of harmless snakes.

1.1 Snake Bites in Sri Lanka
16
In Sri Lanka, close to 37,000 snakebite cases are reported annually to
hospitals 16 , of which about 100 cases will result in the death of the victim.
Most of these deaths occur in rural areas where the patients are brought to
the hospitals at a very late stage due to the lack of transportation facilities.
If the patients are given medical attention without delay these deaths can be
avoided.
We are attacked by snakes mostly due to our lack of understanding of what
their preferred habitats might be. Apart from their naturally occurring
habitats like termite mounds and bandicoot tunnels, venomous snakes like
Cobras, Russell’s vipers and Kraits are attracted to places such as piles of rock
used for construction work where there are plenty of empty spaces for them
to hide, garbage mounds, stacked bricks, piled up coconut leaves, coconut
roots, wood piles etc. In other words, while destroying their natural habitats
we too are unintentionally recreating ideal habitats for them. Additionally,
we also create ideal conditions for their prey, such as rats. Therefore, it is not
a real surprise when snakes, like all other living beings, are attracted to places
where there is plenty of food and shelter.
The human-snake conflict is an issue that will continue to escalate due to
the ever increasing human population and the consequent loss of natural
habitat. However, the threat from snakes to humans remains comparatively
low (approximately 100 deaths per year compared to other hazards such as
accidents involving vehicles which claimed 2,721 lives and injured another
26,847 persons in 2010 alone). Despite this, we are not afraid to travel
on the roads, in a vehicle as we are aware of the different risks associated
with modes of transportation. However, our fear of the unknown (such as
our inability to differentiate a commonly encountered harmless snake from
a deadly venomous snake or our lack of understanding about their ways)
drives us to kill them on sight.
2. What is a Snake ?
Many people fear snakes because they believe that:
• All snakes are venomous and are seeking to kill humans.
• Snakes have an unpleasant skin which is either sticky and slimy or scaly;
• Snakes are dirty and unclean.
However, it should be noted that many people reach the aforementioned
conclusions without even having touched a snake or closely examining them. In
reality, when a person is given the opportunity to closely inspect a snake, they
become pleasantly surprised when they learn that these assumptions are baseless.
• Majority of snakes are non-venomous and attack only if they feel threatened,
in order to catch their prey, and not because they enjoy it. It needs to be
understood that snakes play an important role in maintaining the ecological
balance by controlling the population size of many species.
• Snakes in fact possess a clean, dry skin.
• Some snakes are in fact very colourful and beautiful.
However, these animals have gained an unpopular reputation due to various
reasons, and as a result they are killed by people who are unaware of their ecological
importance. They are an integral part of a balanced ecosystem and play a significant
ecological role as predators, thereby controlling populations of many species
including pests such as rodents. Snakes are also good indicators of environmental
pollution. An additional benefit of these creatures is that their venom,

which contains proteins, can be extracted
for medicinal purposes, hence possessing
an economic value.
Snakes come in a diverse range of sizes,
and are entirely carnivorous typically
swallowing their prey whole. Depending
on their size, their prey also varies from
small insects consumed by small earth
snakes like Typhlops to heavy animals
consumed whole by large pythons.
Left: The scale arrangement of Cylindrophis maculate
(Sri Lanka pipe snake (E); Depath naya (S)), a
harmless burrowing snake. The image shows its tail
rolled up, mimicking a hood of a cobra a typical
defense mechanism against predators.
Above: A Green pit viper, with wide open mouth
showing its fangs.
18
All snakes have razor sharp teeth, which are used to prevent their prey from
escaping., They do not use their teeth to break their prey into smaller parts or
for chewing since they swallow their prey whole. Fangs are specialized teeth
that are only found in venomous snakes. These fangs are tube-like and makes
it possible for the venom to be introduced efficiently into a wound once the
snake strikes, thus immobilizing the prey in the shortest possible time.
The venom and its delivery system are special tools they have developed
through years of evolution, and it must be emphasized that their main
purposes are to aid the capture of prey and self-defense (because snakes are
both predators and prey), and are not intended specifically to hurt humans as
many seem to believe. Snakes that lack venom resort to constriction in order
to immobilize their prey.
Left: Coeloganthus helena (Trinket snake (E);
Katakaluwa (S)), a slightly venomous snake, with
its mouth wide open showing its teeth. The orange
arrow shows its fangs positioned towards the rear
of its mouth, such fangs are known as back fangs.
As mentioned before, not all snakes
are venomous. The composition of the
venom and its quantities vary from
species to species. In general it is a
complex mixture of proteins which can
be categorized according to the organs
they attack i.e. neurotoxic (attacks
the nervous system) or haemototoxic
(attacks the circulatory system).
Depending on their ability to kill their
prey and the composition of venom they
possess, snakes have been grouped in to
four categories i.e. deadly venomous,
moderately venomous, mildly venomous
and non-venomous.

Can you identify them?
Saw scaled viper and Gamma cat snake
3. Identification of
Venomous Snakes
Which one is deadly?
Russell’s viper and Pythons
20
In the animal world, different species use various techniques to survive. These
include their need to find food and defense mechanisms geared to combat
predation. Snakes have the ability to do this quite successfully, even to the
extent of deceiving us human beings.
3.1 Mimicry
The most common mechanism used by snakes is called mimicry. Where
non-venomous species mimic or superficially look like (casually resemble) a
venomous snake, it serves as a warning to others, especially their predators,
that they are venomous and must be avoided.
Only one from these three are deadly venomous, which one is it?

Kraits and
Wolf snakes
15
Although these species look
quite similar, not all of them
are venomous because the
non-venomous ones mimic the
venomous ones i.e. harmless
species mimic
the colour
patterns of
deadly
venomous
snakes.

4. Kraits
In Sri Lanka, there are two species of Kraits, the Indian krait and the Ceylon
krait. They are both deadly venomous. Interestingly, there are six harmless
species that mimic these kraits, including wolf snakes and bridal snakes.
The best and the easiest character that can be used to differentiate the venomous
Kraits from the non-venomous mimics is the dorsal scale row shown in the
figure below.
Venomous Kraits
Large hexagonal scales running
down the spine
Non - venomous mimics
All scales on back identical in size
24
Both snakes shown above display a common form of behavior seen among snakes, whereby
they conceal their heads under their bodies as a defense mechanism. Above: Indian krait that is
deadly venomous. Below: Sri Lanka wolf snake which is a non venomous species.

Prominent white cross bars in a juvenile.
Simple identification character: Large hexagonal shaped scales running down
its spine. Scales on its back are smooth, with the mid row much larger than all
the other surrounding scales. This feature is the most important characteristic
when identifying the species.
Adult specimen, where the cross bars or white lines have reduced and scattered.
4.1 Bungarus caeruleus
Indian krait (E);Thel karawala (S)
26
Toxicity: Deadly venomous
Size: 25 cm- 140 cm
Colouration: Back bluish black to a pale faded bluish grey, with white
cross bars occurring in pairs which become less distinct at the anterior end.
These cross bars are prominent in juveniles or young animals and the lines
gradually disappear or become reduced to scattered cross bars in adults. The
ventral side, or the underside is off-white.
Left: Clear pairs of cross bars of a juvenile. Right: The cross bars gradually diminishing in adults.
But both show enlarged hexagonal scale rows along the spine.
Distribution: Non-endemic. Distributed in the dry, arid, and intermediate
zones.
Behavior: : It is a nocturnal species that is aggressive at night. Commonly found
in and around human settlements. May attack if threatened but generally nonaggressive
during day time. Will roll into a ball with its head well-concealed
when agitated, and might spring out from this position upon further agitation.
Feeds on: Other snakes, geckoes, lizards, rodents etc.
Reproduction: They lay 10- 16 eggs per clutch.

4.2 Non venomous species that
mimic the Indian Krait
Three harmless Wolf snakes mimic the Indian Krait.
Juvenile specimen.
Scales on the back are all identical, and smooth. The subcaudal scales on the
underside on its tail are all divided.
28
4.2.1 Lycodon aulicus
Toxicity: Non venomous
Size: 18 cm- 80 cm
Wolf snake, House snake (E); Alu radanakaya (S)
Adult specimen.
Colouration: Back dark brown to blackish brown, with white cross bars that
divide laterally which are prominent in the anterior end. These cross bars
are prominent in juveniles and young, and the lines gradually disappear or
become reduced to scattered cross bars in adults. Lips are prominently white,
while the ventral or underside is off-white.
Distribution: Non-endemic. Distributed in all parts of the island up to 2000 m
asl. Commonly found in rural areas close to forests, in houses (especially among
piles of wood, piles of stone, foundations and walls where there are plenty of
cracks/crevices), stacked bricks, piled up coconut leaves, and coconut roots etc.
Behavior: : It is a nocturnal species that is aggressive at night and attacks fiercely.
Will roll in to a ball with its head well concealed when agitated, and empty their
bowels with a smell similar to that of rotten dead mice (hence the Sinhala name
“Kunu mee karawala”) as a defense mechanism.
Feeds on: Geckoes, lizards, small rodents etc.
Reproduction: They lay about 20 eggs.

Distribution: This species is endemic to Sri Lanka. Distributed in all parts of
the island up to 2000 m asl. It is commonly found in urbanized and semiurbanized
areas, in houses (especially under flower pots, piles of stone, loose
soil, in foundations and walls where there are plenty of cracks/crevices), stacked
bricks, piled up coconut leaves, coconut roots, piles of wood and in piled up
goods such as clothes, books, boxes etc.
Behavior: It is a nocturnal species that is aggressive at night and attacks- and
bites fiercely. Will roll in to a ball with its head well concealed when agitated,
and empty their bowels with a smell similar to rotten dead mice. Hence, in
Sinhala, it is called “Kunu mee karawala”, owing to the particularity of its
defense mechanism.
Feeds on: geckoes, lizards, small rodents etc.
Reproduction: They lay 8-10 eggs per clutch.
4.2.3 Lycodon striatus
Shaw’s wolf snake (E); Kabara radanakaya (S)
4.2.2 Lycodon osmanhilli
Flowery wolf snake (E); Mal radanakaya (S)
Toxicity: Non venomous
30
Size: 15 cm- 60 cm
Colouration: They show two variations in colour. One morph has a light
brown to a yellowish tinge, with divided yellow cross bars throughout its
back. The other has a uniform light brown coloured body with no white
markings on the back. In both cases the head colouration is light brown with
a yellowish tinge. Eyes black and prominently seen because of the lighter skin
colour compared to others, with white lips upon which every lip scale has a
brown mark in the center.
Scales on the back are all identical, and smooth. The subcaudal scales on
the underside on its tail are all divided.

Toxicity: Non venomous
Size: 9 cm- 28 cm
Colouration: The back is dark brown to blackish brown in colour, with white
cross bars which are prominent at the anterior end that divide laterally and
are broken. In some, these cross bars are yellow. Its lips are white, however
not as distinctly as L. aulicus.The ventral or the underside is off-white.
Scales on the back are all identical, and smooth. The subcaudal scales on
the underside on its tail are all divided.
Distribution: Non-endemic. Distributed in all parts of the island up to 2000
m asl. Commonly found in houses (especially in piled up goods, in home
gardens, mounds of stone, foundations and walls where there are plenty of
cracks/crevices), stacked bricks, piled up coconut leaves, coconut roots, and
piles of timber etc.
Behavior: It is a nocturnal species that is non-aggressive and does not attack.
Will roll in to a ball with its head well concealed when agitated.
Feeds on: Small skink and lizards.
Reproduction: They lay 5-6 eggs per clutch.
An adult specimen showing the typical banding pattern and enlarged scale row on the spine.
4.3 Bungarus ceylonicus
Sri Lankan krait (E); Mudu karawala (S)
Toxicity: Deadly venomous
Size: 100- 110 cm
32
Colouration: Back jet black, with white cross bars. These cross bars are prominent
in juveniles/young and the lines gradually disappear or become reduced to
scattered cross bars in adults. Ventral or the underside is black or alternately black
Juvenile specimen with
prominent white cross
bars. The posterior half
of the head is white
coloured.

and white. Posterior half of the head in juveniles is white. However the white
colour diminishes gradually with age.
Simple identification: Large hexagonal shaped scales running down its spine.
Scales smooth on back. They are much larger than all the other surrounding
scales.
4.4 Non venomous species that
mimic the Sri Lankan Krait
There are three harmless snakes (Sri Lankan wolf snake and two bridal snakes)
that mimic the Sri Lankan krait.
Left: Faded white cross bars in an adult. Right: Prominent white cross bars in a juvenile.
34
Distribution: Wet, intermediate and rarely seen in the dry zone.
Behavior: It is a nocturnal species that is aggressive at night. Commonly
found in and around human settlements. Potentially non-aggressive in
nature, but may attack if provoked or threatened. Will roll in to a ball with its
head well concealed when agitated, and will remain still until the perceived
danger passes. They display this behavior much better than the Indian Krait.
Feeds on: Other snakes, geckoes, lizards and rodents etc.
Reproduction: They lay 6-10 eggs per clutch.
4.4.1 Cercaspis carinata
Sri Lanka wolf snake (E); Dhara radankaya (S)
Toxicity: Non venomous
Size: 65 cm
An adult specimen.
Colouration: Head jet black and shiny, the body is black with white cross bars.
These cross bars are prominent in juveniles/young and as they become adults the
lines gradually disappear or become reduced to scattered cross bars. Ventral or
the underside is black or alternately black and white. Posterior half of the head
in juveniles is white and gradually diminishes with age.

A Juvenile specimen showing prominent cross bars and the
posterior part of the head is white coloured.
36
Simple identification: Scales on the back are deeply ridged, keeled or rough,
a character evident only in this species out of those that mimic kraits.
Scales on its back are all identical, and deeply ridged. scales on the underside
on its tail or subcaudal scales are all single or undivided.
Distribution: Found only in the wet zone.
Behavior: It is a nocturnal species that is aggressive at night. Commonly
found under leaf litter of the forest floor and in home gardens close to forests.
May attack if provoked or threatened. Will roll in to a ball with its head well
concealed when agitated, and will remain the same till the perceived danger
passes.
Feeds on: Geckoes, lizards, skinks, small rodents and rarely on other snakes
etc.
Reproduction: They lay 8-12 eggs per clutch.
4.4.2 Dryocalamus nympha
Bridal snake (E); Geta radankaya, Geta karawala (S)
Toxicity: Non venomous
Size: 70 cm
Colouration: The back of the animal is black with white cross bars which may
be yellowish in juveniles. These cross bars are prominent in juveniles/young and
the lines gradually disappear or become reduced to scattered cross bars in adults.
Posterior cross bands are connected laterally. Ventral or the underside is white.
Simple identification: Possesses a comparatively larger head with a slimmer
neck area. Its body is adapted to climb trees, with a long tail and prominent
ventral ridges on either side.
Scales on the back are all identical and smooth. Underside scales on tail or the
subcaudal scales are all divided.
Distribution: Found in the dry and intermediate zones.
Behavior: It is a nocturnal non-aggressive species. Commonly found in large tree
trunks and under debris, in and around home gardens or human settlements.
Will roll in to a ball with its head well concealed when agitated.

Feeds on: Skinks and eggs of geckoes etc.
Reproduction: They lay eggs. But the number is not known, but a gravid
female specimen with 5 eggs (upon external observation) has once been
recorded.
4.4.3 Dryocalamus gracilis
Scarce bridal snake (E); Meegata radankaya (S)
5. Vipers
Sri Lanka has two species of true vipers (Russell’s viper and Saw scaled viper).
They are both deadly venomous, but very often people get these confused with
non-venomous pythons.
The best and the easiest characters to discriminate the venomous Russell’s viper
from the two non-venomous pythons (Rock python/ Indian python and Sand
Boa) are listed in the table below.
Distinguishing characters Russell’s viper Rock Python Sand Boa
Markings on back
Regular, oval
Irregular, cloud shaped
Irregular, cloud shaped
Distribution of scales on head
Large number of
small sized scales
Both large and
small sized
Small sized, large
number
Head scales
Rough
Smooth
Rough
A preserved museum specimen of Scarce bridal snake which was used to describe the species
scientifically, deposited at the Natural History Museum London.
Toxicity: Non venomous
Snout shape from top
Labial pits
Comparatively pointed
Absent
Blunt
Present
Blunt
Absent
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Size: 50 cm
Remarks: A very rare species, only known from a single record.
Colouration: Back, black with white cross bars. Similar to Dryocalamus
nympha.
Simple identification: Can only be separated by Dryocalamus nympha, by
the number of costal scales. Where D. nympha, has 13 scales and D. gracilis
has 15 scales.
Distribution: Single record from Colombo, wet zone.
Mid body scales on back
Tail scales on back
Sub-caudal/under side of
tail scales
Vestigial hind limbs
Distribution
Rough/keeled
Rough/keeled
Divided
Absent
< 2000 m asl
Smooth
Smooth
Single
Present
< 2000 m asl
Smooth
Rough/keeled
Single
Present
Arid zone and coastal
dry zone
Behavior: Unknown Feeds on: Unknown Reproduction: Unknown

The row of spots on back of a Russell’s viper which are comparatively large and oval
shaped outlined with a black line, with its outer border whitish.
Simple identification: From the large oval spots that run down the body, and
the keeled costal scales. The pair of scales over the eye or the supra ocular, and the
supra nasal scales are large. This species can be identified from its loud hissing
noise.
5.1 Daboia russelii
Russell’s viper (E); Thith polanga (S)
Toxicity: Deadly venomous
40
Size: 120-130 cm
Colouration: Earthy brown with three rows of dark brown spots on the back,
one running down the spine and the other two on the sides of body. The row
of spots on its back are comparatively large and oval shaped, outlined with
a black line, with its outer border whitish, while those found on the lateral
body are small and somewhat oval. On its head a pair of dark brown patches
forms a light brown ‘V’ pointing toward the snout. Ventral or the underside
is off white with black or dark brown blotches.
Head close up of Russell’s viper showing a pair of dark brown patches, which forms
a light brown ‘V’ pointing toward the snout.
Distribution: Found both in the wet and the dry zones < 2000 m asl.
Behavior: It is a nocturnal species that is aggressive at night. Commonly found
in forests, in and around human settlements, paddy fields, under piled-up goods,
and coconut husks etc. If provoked or threatened, it will coil and raise a third
of its body and produce a loud hissing noise which is the loudest of all snakes.

Feeds on: Adults feed on rodents and birds, while juveniles may feed on
geckoes, lizards, frogs etc.
Reproduction: They give birth to 30-35 live young.
5.2 Non venomous species that
mimic the Russell’s viper
Toxicity: Non venomous
Size: Female-100 cm, males-60 cm
Colouration: Earthy brown with large dark brown blotches on back which are
connected but may be separated. Much smaller blotches are found on the side
of its body, which are randomly distributed. Ventral or the underside is pinkish
in colour.
The two non-venomous pythons (rock python and sand boa) superficially
look a lot like a Russell’s viper. Out of which the sand boa is more similar but
is less commonly found.
5.2.1 Eryx conicus
Sand boa (E); Wali pimbura, Kota pimbura (S)
Mid body colour pattern of a Sand Boa.
Simple identification: Smooth mid body scales, and the blotches on its back.
Scales on the back of its tail are deeply ridged (keeled/rough) The subcaudal
scales on the underside of its tail are single or undivided.
43
A close up view of the head of a Sand boa showing its
rough and small even sized scales.

Distribution: Found only in the coastal dry zone and arid zone.
Behavior: It is a nocturnal species that moves slowly and is lethargic. It is
rare but can be found burrowed within soil in dry and arid parts of the
island. They constrict their prey to immobilize them.
Feeds on: small mammals, geckoes, lizards, skinks, frogs etc.
Reproduction: They give birth to live young.
5.2.2 Python molurus
Rock python (E); Dara pimbura, Ran pimbura (S)
Large sized blotches on mid body.
Simple identification: The pattern of blotches on its body. The subcaudal scales
on the underside of its tail are single or undivided.
44
Close up of head showing the markings of an arrow pointing towards head, and
scales of different sizes.
Toxicity: Non venomous
Size: 600 cm
Colouration: Whitish or yellowish with three rows of large sized blotches
on back. Colours vary from a light brownish tinge to a dark brown. The row
of blotches on the back is much larger than the rows on the side of body.
Ventral or the underside is cream with small dark brown or black spots.
Distribution: < 2000 m asl
Behavior: A slow moving nocturnal species, but if threatened will move fast to
hide. If threatened they will also coil and warn by hissing several times before
attempting to bite. It is a highly camouflaged species that lives amongst leaf
litter, and well-adapted as an ambush predator. Uncommon but can be found in
forests, and in semi-aquatic environments. It is also well-adapted to climb trees.
They constrict their prey to immobilize them.

Toxicity: Deadly venomous
Size: 30-40 cm
Colouration: Light brown or pale earthy brown with a series of dark brown
spots outlined with whitish lines on back. On its head there is a distinct off-white
marking which may look like an arrow, or the foot print of a bird, or a crucifix.
Ventral or the underside is off white to light brown, with small dark brown spots.
The vestigial
hind limbs of
Python mollurus
(Rock Python).
Feeds on: Large to small mammals (except those that are carnivorous and
very large species), flying mammals, small sized crocodiles, land monitors,
birds etc. They constrict their prey to immobilize them.
Reproduction: They lay 12- 40 eggs, and are the only snakes in Sri Lanka
that protect and incubate their eggs.
5.3 Echis carinatus
Saw scaled viper (E); Wali polanga (S)
Distinct marking on the head of Saw scaled Viper, which may look like an arrow, a
foot print of a bird or a crucifix.
Simple identification: The off-white distinct marking on the head.
Costal scales are keeled/rough and identical in size except for the pair just above
the eye (supra ocular) and inter-nasals, which are smooth and larger in size. The
subcaudal scales on the underside of its tail are single or undivided.
46
Distribution: Found in the arid and the coastal dry zone.
Behavior: It is an aggressive nocturnal species that is rarely diurnal. When
threatened they coil and make a small warning noise by rubbing their body coils
against each other. It is a highly camouflaged species in its natural habitat which
is sand-mixed dry leaf litter. Potentially aggressive and will attack if provoked.
Has limited distribution, hence uncommon but commonly found in its preferred
habitat, the sand dune forests and surrounding home gardens. During the dry
season, they are commonly seen under palmyrah leaves (Borassus flabellifer),
which have fallen close to wells and places where there is water.
Feeds on: Geckoes, lizards, frogs, small rodents etc.
Reproduction: They give birth to live off spring.

5.4 Non venomous species that
mimic the Saw scaled viper
5.4.1 Boiga triginata
Gamma cat snake (E); Garandi mapila, Ran mapila,
Kaeta mapila (S)
Toxicity: Non venomous
Size: 70-100 cm
Colouration: Light brown or pale earthy brown with a series of off white ‘V’
shaped markings outlined in dark brown or black running down its spine. On its
head there is a distinct off whitish ‘Y’ shaped marking. Ventral or the underside
is light yellow, with small dark brown spots on either side.
Distinct ‘Y’ shaped marking on the head of a Gamma cat snake.
48
Simple identification: The off whitish distinct ‘Y’ shaped marking on head.
Underside scales on tail or subcaudal scales are divided.
Distribution: Found in the arid, dry and intermediate zones.
Behavior: It is a nocturnal species. When threatened they make a warning noise
by patting its tail on to a surface. Non aggressive, and can be commonly found
on trees, piled up goods, and in and around human settlements etc.
Feeds on: geckoes, lizards, skinks, small birds, small sized bird’s eggs, small
rodents etc.
Reproduction: They lay 8-12 eggs per clutch.

6. Cobra
There is only one species of cobra (Indian cobra or Spectacled cobra) found
in Sri Lanka. It is a deadly venomous species, and is the most commonly
known venomous snake, amongst people in the island.
6.1 Naja naja
Indian cobra, Spectacled cobra (E); Naya, Nagaya (S)
Toxicity: Deadly venomous
Size: 180 cm
Colouration: The colour on its back varies from dark brown to dark reddish
brown or dark grey to grayish black with white or light yellow cross bars. These
cross bars are either incomplete or complete with sets of four to six bands
grouped at times. Hood contains a large usually white-coloured spectacle shaped
marking, and the surrounding area is reddish. The ventral or the underside may
vary from white to pale yellow to light brown, while some may have a single
colouration, others may have cross bars or blotching.
50
The prominent, large
spectacle shaped marking
on the hood of a cobra
which is commonly
white.
Simple identification: It forms a distinctive hood, raising its body and displaying
the prominent spectacle shaped marking on the head. When the hood has not
expanded, the easiest way to identify this snake is by the observing its rostral
scale, the area below the eye which is outlined in black.
The subcaudal scales on the underside of its tail are divided.

Distribution: < 2000 m asl.
Behavior: It is a diurnal species that is rarely nocturnal (but large sized cobras
may be encountered at night very rarely). Commonly found in and around
human settlements, paddy fields, under piled-up goods, piled-up coconut
husks etc. A potentially non-aggressive species, but if threatened or provoked
will expand its hood and warns by its fake attacks.
Feeds on: Small mammals, frogs, lizards, monitors, other snakes, birds and
their eggs etc. Juveniles may consume skinks, geckoes etc.
Reproduction: They lay 20-40 eggs per clutch.
Remarks: Juvenile cobras could be confused with juvenile rat snakes.
Literature cited
1. Smith, E., Manamendra-Arachchi, K. and Somaweera, R. (2008). A new
species of coralsnake of the genus Calliophis (Squamata: Elapidae) from
the Central Province of Sri Lanka. Zootaxa. 1847:19–33.
2. Wickramasinghe, L.J.M., Vidanapathirana, D.R., Wickramasinghe,
N. and Ranwella, P.N. (2009). A New Species of Rhinophis Hemprich,
1820 (Reptilia: Serpentes: Uropeltidae) from Rakwana massif, Sri Lanka.
Zootaxa. 2044: 1–22.
52
People often get confused between the more widespread and harmless Rat snakes
with cobras. The rat snake plays a very important role as a pest controller.
A close-up view of the head of a Rat Snake showing black lines outlined on scales
bordering the lip, which is the simplest feature that can be used for identification
of rat snakes.
3. Maduwage K., Silva A., Manamendra-Arachchi K. and Pethiyagoda R.
(2009). A taxonomic revision of the South Asian hump-nosed pit vipers
(Squamata: Viperidae: Hypnale). Zootaxa. 2232:1–28.
4. Gower, D.J. and Maduwage, K. (2011). Two new species of Rhinophis
Hemprich (Serpentes: Uropeltidae) from Sri Lanka. Zootaxa. 2881:
51–68.
5. Wickramasinghe, L.J.M., Conservation Status of the Reptile Fauna of Sri
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der review)
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reptiles of Sri Lanka. New Holland publishers (UK). 144 pp.
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(Accessed: 6 December 2012).