Encounter: Malabar Pit Viper

Little did we know that we were being watched by a silent and mysterious presence on a wooden beam behind us
The first time I went to Agumbe Rainforest Research Station, I remember walking for hours in the night, hoping to catch a glimpse of Malabar Pit Vipers. No luck. This time, on a trip with the other ogres, nearly two full days passed without incident.
The heat-sensing pits between the eye and nostril can be clearly seen
On the second night, Sandy and I were walking towards our tent in pouring rain, guided only by the small beam of my torch. I almost stepped on a twig that lay across my path — a dry twig that appeared to be mottled with pale lichen growth in bluish green and brown. Except this twig was moving!
“Stop!” I shrieked. Sandy bumped into me from behind. I guided the torch beam towards the head of the “twig”. One good look at the snake’s triangular head was enough to conclude that it was a viper. That, in addition to the colour pattern, pointed us in the right direction. This was a Malabar Pit Viper (Trimeresurus malabaricus)!
As I watched the fella slither past me slowly, I asked Sandy to go and fetch the others. As he ran back, I stood there in pouring rain and pitch darkness observing the snake cross the path and slowly enter a dense thicket. At times, when a twig or branch was too high, the snake lifted itself upwards like a straight stick and hooked its head on the twig. Then, it pulled itself up. This behaviour pointed to the snake’s tree-dwelling lifestyle.
By the time Sandy came back with Beej, the viper had almost dissolved into the shrub, aided by perfect camouflage. I was upset that the others had not had a good look at the snake.
The brown markings on green can be seen
Malabar Pit Vipers are nocturnal and are generally found in low bushes, trees and on rocks. During the day they are inactive and may be seen basking. They are endemic to the Western Ghats and are found between altitudes of 600 to 2134 metres. Adult snakes can grow to 55-79 centimeters. The longest ever measured was 105 centimeters. The triangular head is broader than the neck. They are typically green but appear in other morphs and a lot of variations have been recorded, including reddish-brown, yellow, etc. On its back the snake is olive or brown with black or brown spots, which may be joined to form a zigzag pattern. The sides have faint yellow spotting and the tail has yellow and black markings. The pupils have vertical slits. Malabar Pit Vipers are ovoiviviparous — the eggs form, develop and hatch within the mother’s body.
Pit vipers, which are classified under the subfamily Crotalinae in the family Viperidae, are distinguished from other vipers by the presence of a pair of heat-sensing pits located between the eye and nostril. These organs help the snake detect the body heat of warm-blooded prey even in absolute darkness.
The other ogres were disappointed at missing the snake the night before but at 4 pm the next day, our luck turned. The ogres were busy treating a Vine Snake like a supermodel. After about 20 minutes all except me and Andy left the scene. After lingering for another ten minutes, we decided to go back to the room to pack and freshen up before our return journey. Just as we left Prashanth, the station manager, called out to us. He pointed to a wooden beam just under the roof of the dining area and said, “Look who’s sitting here.” There lay a Malabar Pit Viper, coiled, calm and relaxed.
Relaxed and lazing
Observing from high above
It dawned on us that all the while, as we were photographing the Vine Snake, this chap was watching the drama from its high throne!
The others arrived and we took good, long looks at the snake. Malabar Pit Vipers have prehensile tails (adapted to grasp or hold) and this perhaps helps them to anchor themselves on branches or twigs while they lunge at their prey. Here, the snake had used its tail as a kind of hinge to loop it against the beam in the absence of anything else to hold on to.
We made sure to keep our distance as vipers, though slow, are known to be capable of extremely fast strikes. The venom is mildly haemotoxic — the toxins destroy red blood cells, disrupt clotting of blood, and causes tissue damage. In humans it results in pain and swelling.
The prehensile tail is used as a hinge in the absence of anything to hold onto
I’m sure the snake wouldn’t have wanted to waste its venom on us, and instead save it for the geckos, tree-frogs, shrews, and birds which make up a large part of its diet. Pit vipers have erectile fangs which are kept folded against the roof of the mouth. They are brought into place only when striking.
After we observed and photographed the snake, I asked Prashanth if he would move the snake since it was close to the dining area. To my surprise, he said they would leave it there and let it decide its own way out at night. Though I was a little concerned about slithering vipers that might end up over our heads or under the dining table, I was also glad that ARRS offered a haven for snakes where they had right of way.
Text: Arun
Photographs: Sahastrarashmi and Arun
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