have discovered five new species of shrub frogs from the
Western Ghats, one of the globally recognised biodiversity
The frogs, belonging to the the Old World tree frog
family Rhacophoridae, were discovered by researchers from
University of Delhi and Kerala Forest Research Institute and
University of Minnesota as part of a long comprehensive study
on the Shrub frogs (genus Raorchestes) of the Western Ghats,
carried out over a period of nearly 10 years.
Researchers said the new species were identified and
found to be distinct based on multiple criteria, such as their
external morphology, DNA, calling pattern, behaviour, and
other natural history observations.
The findings are published in a scientific article
titled ''An integrative approach to infer systematic
relationships and define species groups in the shrub frog
(genus Raorchestes), with description of five new species from
the Western Ghats, India''.
The authors are Sonali Garg, Robin Suyesh, Sandeep
Das, Mark A Bee, and Prof S D Biju and it is published in the
current issue of the International journal PeerJ.
The study was carried out under the leadership of
Delhi University Professor Biju.
While one of the new species called Raorchestes
drutaahu (Fast-calling Shrub Frog) was discovered from two
localities: Kadalar in Idukki district and Siruvani in
Palakkad district of Kerala, another one named Raorchestes
kakkayamensis (Kakkayam Shrub Frog) was found only in the
vicinity of Kakkayam dam in the southern state.
Raorchestes keirasabinae (Keira''s Shrub Frog), a
unique tree frog inhabiting the highest canopy layers, was
found in Agasthyamalai and Anamalai hills in the southern
The species is named after young nature lover Keira
Sabin, in appreciation of the long-time support and commitment
of the Andrew Sabin Family Foundation towards amphibian
research and conservation around the world.
Raorchestes sanjappai (Sanjappa''s Shrub Frog), a
beautiful green shrub frog, was discovered from the Wayanad
region of northern Kerala.The species is named after Dr M
Sanjappa, a renowned Indian Botanist and former Director of
the Botanical Survey of India.
TheRaorchestes vellikkannan (Silver-eyed Shrub Frog)
was discovered in the Siruvani hills and adjoining regions of
the Silent Valley National Park.
The name is derived from Malayalam ''velli'' (meaning
silver) and ''kannu'' (meaning eye), referring to its distinct
silver eye colour.
According to the researchers, over 80 per cent of the
globally known shrub frogs are restricted to the Western
Ghats, and most species are known to have narrow geographical
For the first time, male calls for as many as 48
species of shrub frogs were studied, they said.
According to the study, the shrub frogs of the genus
Raorchestes exhibit highly unique and diverse eye colour and
Biju, who is the head of Department of Environmental
studies in Delhi University, said the study was a testament to
how little is known about the most threatened group of
vertebrates in India.
"Shrub 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."
"Our work has once again added new insights on what
we thought we knew about this group of frogs, from how to
identify different species and their affinities to each
other, to where they live and how vulnerable they may be to
various anthropogenic threats," he said.
Scientists are now tracing potential evidence for
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," said Sonali Garg, the lead author of
the study.PTI TGB