In a discovery reminiscent of a crime thriller, an unusual sound in a video soundtrack has led to the discovery that a rare salamander species from the hill district of Darjeeling in West Bengal, is capable of vocalising .
Sibling wildlife filmmakers Ajay and Vijay Bedi were editing footage recorded for a documentary on amphibians, called the Secret Life of Frogs , in their studio in Delhi when they heard a low ptaak sound.
“When we checked up with researchers, we learnt that this was unique,” said Vijay Bedi, 40, who comes from a family of wildlife film-makers.
The filmmakers later teamed up with scientists at Sri Venkateswara College (SVC) from Delhi University and wrote up their findings about the salamander species, Tylototriton himalayanus, in a peer-reviewed scientific publication, Salamandara — German Journal of Herpetology.
Lizards are reptiles with dry scaly skins and can only breathe through their lungs. Amphibians, like salamanders and frogs, need to be around moist regions as they also respire through their skin.
While there are about 762 salamanders species known globally, only two have been found in the Indian subcontinent. Tylototriton himalayanus — the species caught on camera by the Bedis — was only reported to the scientific world in 2015 and the brothers were filming the species to know more about its reproductive behaviour, habitat and adaptation.
T. himalayanus, also known as the Himalayan crocodile newt or the Orange warted Salamander is usually found in temporary water pools, marshes and slow-moving drainage.
Previous studies had pegged T. himalayanus as belonging to the only other such species of salamander in India — T. Verrucosus and there were reports that the creatures may be capable of “vocalising.” However there were neither descriptions nor recordings of their sounds.
“This opens up new avenues for scientific research as calls have rarely been tested as part of behavioural study on the salamanders as they are known to be silent amphibians,” Robin Suyesh, Assistant Professor, Department of Environmental Sciences at SVC said in a statement.
“Testing new hypothesis using these low frequency calls produced by these salamanders can provide new insight. This sound recorded of their call by Bedi brothers has given new insight to scientific community. And a great example how filmmakers can be part of big researcher community and play an important role as to the use of their film as tool for conservation,” added Prof. Suyesh, who is also a co-author of the scientific publication.
In the footage, the two males were recorded vocalising and producing a “low frequency call” of 656 Hz. The reason for the male’s calls are yet to be deciphered.
“We found them in the wetlands and very little is known about them. It was important for us to provide as much visual detail so that this species can be understood and appreciated even by people who aren't scientists,” said Mr. Bedi.
The species currently face various threats from siltation in ephemeral ponds, destruction of host plants as fodder for domestic animals, household waste leading to eutrophication, increasing traffic on country roads, introduction of invasive species, exploitation for traditional medicine, pesticide pollution and detergent in water bodies.