Five new species of shrub frogs found in Western Ghats

Raorchestes vellikkannan.

An Indo-US team of biologists on Wednesday reported the discovery of five new species of shrub frogs from the Western Ghats, one of India’s biodiversity hotspots.

The scientists discovered these new species as part of a long comprehensive study on the shrub frogs (genus Raorchestes) of the Western Ghats spanning over a period of nearly ten years. The new species were identified and found to be distinct on the basis of their external morphology, DNA, calling pattern, behaviour, and other natural history observations.

They were named Raorchestes kakkayamensis after the place of its discovery Kakkayam; Raorchestes keirasabinae after young nature lover Keira Sabin and Raorchestes sanjappai after M Sanjappa, a renowned Indian Botanist and former director of the Botanical Survey of India. One species has been named Raorchestes drutaahu because of its unique calling pattern. The species name is derived from Sanskrit ‘druta’ (meaning fast) and ‘ahu’ (meaning call).

The last one has been named Raorchestes vellikkannan because of its distinct eye colour it gets its name Malayalam ‘velli’ (meaning silver) and ‘kannu’ (meaning eye). All of them have been found in Kerala.

“This study is a testament to how little is known about the most threatened group of vertebrates in India. The shrubs frogs are among the most researched groups of frogs in India, with frequent new discoveries being made over the past two decades. Yet, we are far from fully understanding their existing diversity and uniqueness,” said team leader S D Biju, a professor at Delhi University and India’s leading frog hunter.

Over 80 per cent of the globally known shrub frogs (genus Raorchestes) are restricted to the Western Ghats, and most species are known to have narrow geographical ranges. The study provides several new insights into the behaviour of such amphibians.

The biologists are now tracing potential evidence for the population decline of the five newly discovered species, and any threats that they may be facing within their known ranges, in order to protect them from extinction.

“Several new species are often threatened even before they are formally named and known to science. Many of these may already be extinct before they are discovered. It is an unfortunate fate that scientists call as — the nameless extinction,” added DU researcher Sonali Garg, the lead author of the study.