A team from Dehradun-based Wildlife Institute of India (WII) has rediscovered a species of a snake in Assam considered extinct after a gap of 129 years since it was first seen.

The species ‘Hebius pealii’, called Assam Keelback, was first seen in 1891 when a British tea-planter Samuel Edward Peal collected two male specimens from Sibsagar district in Assam.

One of them was kept at the Zoological Survey of India (ZSI) in Kolkata and the other in London’s Natural History Museum (NHM). The snake was never seen after that and was believed by some to be extinct.

It was accidentally found in a reserve forest, 118km from the place where it was first collected, on the Assam-Arunachal Pradesh border in September 2018 when a team from WII was retracing steps of the Abor Expedition, a military expedition by the British against Abors in 1911.

The find was published on June 26 in Vertebrate Zoology, an international journal published from Germany.

“To commemorate the Abor Expedition, which besides being a military campaign had resulted in the collection of a large number of animals and plants, we revisited the area to find out the changes that had occurred in a century,” Abhijit Das, a scientist in endangered species management department of WII, said.

“Since the British started their expedition from Dibrugarh in Assam from a place near Poba reserve forest on the Assam-Arunachal Pradesh border, we also began there. It was in a marshy wetland inside the forest, where I encountered this snake endemic to Assam and not seen for the last 129 years. It was totally unexpected as people had thought it to be extinct,” he added.

Das, an expert on snakes of Assam and northeast India, caught the snake, an adult female which is bi-coloured—dark brown above and pale mid-ventrally. To confirm the species, the WII team had to get details from NHM, London as the specimen at ZSI had got damaged.

“We got data from London and also did DNA profiling to establish that the specimen found in Poba reserve forest is Assam Keelback. We were lucky that the specimen in London was intact or else it would have been difficult to identify the snake,” said Das.

“Now we know what kind of habitat this snake, which measures around 50-60cm and is non-venomous, resides in. We need to look for more members of this species in those areas and also undertake special efforts to protect these micro-habitats, marshy wetland within evergreen forests” he added.