Western Ghats Reveal Five New Species of Shrub Frogs!

Raorchestes Genus Expands with Stunning Discoveries from Kerala and Tamil Nadu

The silent forests of the Western Ghats have once again spoken — through the distinct, vibrant calls of frogs. A new study published in PeerJ (2021) by Garg et al. has unveiled five previously unknown species of shrub frogs from the Raorchestes genus. These discoveries are the result of meticulous fieldwork, acoustic analysis, genetic studies, and morphological comparison — a shining example of integrative taxonomy at work.

The five new frogs are:

  • Raorchestes drutaahu – The Fast-calling Shrub Frog

  • Raorchestes kakkayamensis – Named after Kakkayam, a forested hill tract in northern Kerala

  • Raorchestes keirasabinae – A tribute to young wildlife enthusiast Keira Sabin

  • Raorchestes sanjappai – In honour of Indian botanist Dr. M. Sanjappa

  • Raorchestes vellikkannan – Literally “Silver-eyed Shrub Frog” in Malayalam

 The Star of Munnar: Raorchestes drutaahu

The name drutaahu comes from the Sanskrit for “fast calling,” and this frog lives up to its name. Found in the high-elevation shola forests of Kadalar, Munnar, this species produces a unique, rapid, pulsatile call not heard in any other frog of its kind.

  • Distinctive Call: Short bursts with a fast tempo

  • Size: Around 22.9 mm in length (male)

  • Habitat: Mid-elevation evergreen forests (~1400 m)

These frogs are active during the night, calling from shrubs, tree trunks, and forest edges. Their behavior and call rate make them particularly unique among Raorchestes.

Other Newcomers to Science

Each of the remaining four species discovered in the study highlights a unique habitat or story:

Raorchestes kakkayamensis

Found in the Kakkayam region of northern Kerala, this species was previously misidentified. It inhabits dense vegetation and its call is a critical identifier. The species highlights how remote forest patches in the Ghats still hide undescribed biodiversity.

Raorchestes keirasabinae

Named to inspire young conservationists, this frog lives in the Vellarimala range. Its description comes with the hope that the next generation will value and protect forest ecosystems.

Raorchestes sanjappai

This frog, found near Agasthyamalai, is named after Dr. M. Sanjappa, a pioneer in Indian botany. Its discovery in southern Tamil Nadu underscores how even well-explored areas hold surprises.

Raorchestes vellikkannan

With its striking silvery eyes, this frog was discovered in Ponmudi Hills, Kerala. It prefers low bushes and saplings, calling softly through the night. Its Malayalam name reflects local roots.

 Why This Discovery Matters

The Raorchestes genus — known for its diversity and endemism — has now expanded to over 50 described species, most of which are found only in the Western Ghats. These frogs are often visually cryptic, meaning they look similar, but their DNA and call structures reveal their uniqueness.

This study reinforces the importance of using genetic data, bioacoustics, and field observations to uncover the true biodiversity of India’s mountain rainforests.

 Conservation Implications

Each of these species occupies a narrow geographic range, often restricted to single hill ranges or isolated forest patches. That makes them highly vulnerable to habitat loss due to tourism, monoculture plantations, and changing climate patterns.

Protecting these frogs means protecting the entire ecosystem they represent — from leaf litter to canopy.

📖 Citation

Garg, S., Suyesh, R., Das, A., Bee, M.A., & Biju, S.D. (2021). An integrative approach to uncover overlooked diversity in shrub frogs (Raorchestes) of the Western Ghats, India with description of five new species. PeerJ, 9:e10791. https://doi.org/10.7717/peerj.10791