In search of pit vipers

A group scours the Western Ghats for these under-studied snakes


A pit viper expedition. Photographs: Nirmal Kulkarni
A pit viper expedition. Photographs: Nirmal Kulkarni

The forest is dark and damp as the sun struggles hard to break through the leaves. During the monsoon, incessant rain batters the dense forest canopy, rainwater drips to form trickling streams where the mist plays hide and seek.

This is the enchanting forest of the Western Ghats, known as a biodiversity hot spot, where the bioluminescent fungi light up the dark forest floor—imagine the forest from the movie Avatar.

A female Malabar pit viper
A female Malabar pit viper

These forests are home to a group of venomous snakes—pit vipers. “(They are) called pit vipers because of the presence of a deep pit in the region (between the nostril and the eye) on either side of the head. These specialized senses contain heat-sensitive receptors, which can detect and receive infrared heat rays and distinguish not only the direction of an object but also its distance, sensing changes of even 0.001 degree centigrade accurately. This enables pit vipers to detect warm-blooded prey with accuracy and subdue it even in total darkness,” says Nirmal Kulkarni, herpetologist and head of Mhadei Research Centre, Goa.

A male Malabar gliding frog
A male Malabar gliding frog

In India, the 28 plus pit viper species are restricted to the high-rainfall zones of the Western Ghats, the North-East, Himalayas and the Andaman and Nicobar Islands. “Being venomous, they are feared and in most areas killed on sight, and their conspicuous niche habitat destroyed,” adds Kulkarni.

For the past seven years, during the monsoon, Kulkarni has been leading a motley group of nature enthusiasts and researchers interested in herpetology on a pit viper expedition (PVE) in the Western Ghat forests bordering Goa, Karnataka and Maharastra. The objective is to bring into focus these charismatic yet under-studied group of venomous snakes. PVE is the only expedition of its kind in Asia, and the participants (a 10-member team) are drawn from various walks of life.

A praying mantis sits on a female Malabar pit viper.
A praying mantis sits on a female Malabar pit viper.

This year, the PVE team travelled extensively in the forest habitats of Dodamarg forests, Mhadei Wildlife Sanctuary and Mollem National Park in Goa and parts of Kali Tiger Reserve in Karnataka.

“The aim is to map, monitor and spread conservation awareness in key pit viper locations in the Northern Western Ghats of India over a period of time and gather data on conservation status of varied species of Indian pit vipers. Pit vipers are important but amongst the lesser-studied groups in the Asian region. They are, however, considered key bio-indicators, and therefore it is critical to develop effective, long-term management plans to obtain baseline data on their occurrence and abundance,” says Kulkarni.

Support for this expedition led to The Indian Pit Viper Conservation Initiative in July. It aims to make a rapid, quantitative assessment of Indian pit viper status in the Western Ghats, locate and collect baseline data on niche habitats, formulate an action plan for pit viper conservation and educate snake rescuers in the safe handling and importance of forest species of venomous snakes. “Today, after seven years, and in collaboration with various research stations, field ecologists and snake rescuers, positive publicity for the conservation of three species—the hump-nosed pit viper (Hypnale hypnale), the Malabar pit viper (Trimeresurus malabaricus) and the bamboo or green pit viper (Trimeresurus gramenius)—among the local people has been attained,” says Kulkarni.

READ MORE