Frog the size of a thumbnail found in the Western Ghats

NEWDELHI: They are as small as a five-year-old child’s thumbnail; and leap out of their hideouts after sundown to make their presence felt in the Western Ghat jungles with cricket-like chirps.

They are among seven new species of frogs, some of the tiniest in the world, discovered by Indian scientists. These nocturnal amphibians measure between 12.2mm and 15.4mm.

The discovery makes the rich but eco-sensitive Ghats the second biggest global amphibian hotspot after Brazil’s Atlantic Forest, a research paper reported on Tuesday. Named after the place of discovery such as Sabarimala and Athirappilly in Kerala, the paper said they were found in “damp tree leaf litter or marsh vegetation”, unlike night frogs that reside along streams.

“The miniature species are locally abundant, but they have probably been overlooked because of their extremely small size, secretive habits and insectlike calls,” said Delhi University research scholar Sonali Garg, the paper’s lead author.

Locals knew about these frogs, but never thought they make sounds like crickets, explained SD Biju, a Delhi University taxonomy professor who guided the five-year painstaking research.

The first of the new discoveries was sighted in 2012, but differentiating their genre using DNA sampling and analyzing their unique calls took time, he said.

The paper stressed that more studies were required to understand the “evolutionary advantages of miniaturization and adaptation to terrestrial life” within the Nyctibatrachidae family, comprising largely robust torrential frogs.

Most of these frogs are endemic to the Western Ghats and represent an ancient group that diversified on the Indian landmass approximately 70-80 million years ago, according to a statement by peer reviewed open access journal, PeerJ, which published the study.

“Once the extinction risk is assessed and we can better understand the realities of each species, this would allow for the tailoring of both research and conservation actions,” said Ariadne Angulo, co-chair of a specialist group on amphibians at UN’s wildlife monitoring authority, International Union for Conservation of Nature (IUCN). With the discovery, the number of night frog species found in the region has gone up to 35, of which 20% are extremely tiny.