Unlocking the Deccan Plateau’s Hidden Biodiversity: Researchers Discover Two New Cryptic Gecko Species in Telangana

HYDERABAD, INDIA — In a significant contribution to South Asian herpetology, a collaborative team of Indian researchers has formally described two new species of geckos belonging to the genus Hemidactylus from the rugged terrain of Telangana State. Discovered amidst the rocky scrub forests and agrarian fringes of the Nalgonda and Warangal districts, these newfound reptiles belong to the Hemidactylus brookii species group and the murrayi clade.

The discovery underscores the ecological richness of the Central Plateau within the Deccan Peninsula, a region that continues to yield cryptic biodiversity previously hidden in plain sight. Named Hemidactylus cairnicola and Hemidactylus koyaorum, these two distinct species expand our understanding of Indian gecko taxonomy and highlight the urgent need for targeted conservation strategies in rapidly transforming semi-arid landscapes.

The comprehensive findings have been detailed in a peer-reviewed paper published in the European Journal of Taxonomy.

Main Facts: Meet India’s Newest Geckos

The discovery adds two remarkable organisms to the Indian faunal database. Both species are small-to-medium-sized geckos that have adapted specialized morphological and behavioral traits to survive in the rocky, often harsh micro-habitats of the Deccan Plateau.

Hemidactylus cairnicola

Discovered in the Nalgonda District, Hemidactylus cairnicola is a medium-sized gecko with a maximum snout-to-vent length of approximately 49 millimeters (mm). Its morphology is tailored for life among rocks: it possesses a relatively stout, slightly depressed body and a broad head that is distinctly separated from its neck.

• Scalation and Appearance: The dorsal surface of H. cairnicola features granular scales intermixed with enlarged, strongly keeled, conical tubercles arranged in 13 to 15 longitudinal rows stretching from the occiput to the base of the tail. Its belly is lined with approximately 31 to 32 scale rows across its width and 137 to 145 longitudinal ventral scales. Male specimens bear seven or eight femoral pores on each side.
• Coloration and Camouflage: The species exhibits a light-brown to gray coloration that shifts dynamically depending on the background substrate, offering exceptional camouflage against the black rock cairns and exposed surfaces it calls home. The head is adorned with several dark spots alongside paired preocular and postocular streaks, while irregular dark markings extend across the torso and tail. The underside remains pale and unpatterned.
• Ecology and Habitat: Primarily nocturnal, H. cairnicola spends daylight hours sheltering deep within rock crevices. However, researchers have observed individuals basking or resting on exposed rocks during cooler winter days and rainy periods. Operating near human settlements, including villages and traditional Lambada communities, this gecko shares its habitat with a diverse suite of reptiles, including other gecko species, skinks, agamid lizards, and the Indian sand boa (Eryx johnii).

Hemidactylus koyaorum

Endemic to the Deccan Peninsula biogeographic zone, Hemidactylus koyaorum is currently known strictly from its type locality within the Warangal District of Telangana. Taxonomically linked to the Hemidactylus brookii group and the murrayi clade, H. koyaorum is most closely related to H. treutleri, another regional gecko species.

Despite their morphological similarities—a hallmark of "cryptic" species complexes—genetic data sets the two apart definitively. Mitochondrial ND2 gene sequences reveal a profound genetic divergence of 7.0% to 13.5% between H. koyaorum and H. treutleri. Furthermore, genetic distance metrics separate the two newly discovered species from one another by a 9.5% to 10.0% sequence divergence, confirming their status as independent evolutionary lineages.

Chronology of the Discovery: From Fieldwork to Formal Description

The unearthing of H. cairnicola and H. koyaorum is the culmination of meticulous, multi-institutional scientific exploration spanning several years across remote and under-surveyed pockets of Telangana.

Phase 1: Reconnaissance and Field Surveys

Herpetologists and field biologists frequently target the Deccan Plateau’s rocky scrub forests due to their reputation as hotspots for cryptic endemism. During nocturnal and crepuscular field expeditions across the Nalgonda and Warangal districts, researchers collected voucher specimens of Hemidactylus geckos that did not neatly fit the diagnostic keys of existing, documented species. Their unique behavioral patterns, distinct micro-habitat preferences, and subtle morphological variations signaled potential new taxa.

Phase 2: Integrative Taxonomy and Genetic Sequencing

Recognizing that morphological data alone is often insufficient to untangle complex groups like the Hemidactylus brookii complex, the team turned to integrative taxonomy. Tissue samples were processed for molecular analysis. By sequencing the mitochondrial ND2 gene, the researchers mapped out phylogenetic trees that compared the unknown Telangana specimens against known reference sequences of allied species like H. treutleri.

Phase 3: Morphometric Analysis and Peer Review

Concurrently, the team conducted rigorous morphological examinations. They measured snout-to-vent lengths, counted scale rows, evaluated tuberculation patterns, and documented femoral pore counts in males. Once the molecular divergence thresholds were confirmed—demonstrating distinct evolutionary separation well above standard species-delimitation benchmarks—the formal descriptions of Hemidactylus cairnicola and Hemidactylus koyaorum were compiled. The manuscript was submitted to the European Journal of Taxonomy, undergoing rigorous peer review before its formal publication.

Supporting Data: The Multidisciplinary Research Team

The discovery is a product of cross-institutional collaboration, bringing together experts in taxonomy, molecular phylogenetics, wildlife conservation, and regional ecology from across India.

+---------------------------+------------------------------------------------------------------------------------+
| Researcher                | Affiliation                                                                        |
+---------------------------+------------------------------------------------------------------------------------+
| Bharath Bhupathi          | Freshwater Biology Regional Centre, Zoological Survey of India, Hyderabad          |
| Sumidh Ray                | P.G. Department of Zoology, Fakir Mohan University, Balasore, Odisha               |
| B. Laxmi Narayana         | Zoological Survey of India, FPS Building, Indian Museum Campus, Kolkata            |
| Amirtha Balan             | Nehru Zoological Park, Bahadurpura, Hyderabad                                      |
| Deepa Jaiswal             | Wildlife Institute of India, Chandrabani, Dehradun                                 |
| Pratyush P. Mohapatra     | Freshwater Biology Regional Centre, Zoological Survey of India, Hyderabad          |
+---------------------------+------------------------------------------------------------------------------------+

Genetic Metrics at a Glance

• Target Gene: Mitochondrial ND2
• Divergence (H. koyaorum vs. H. treutleri): 7.0% – 13.5% uncorrected genetic distance
• Divergence (H. cairnicola vs. H. koyaorum): 9.5% – 10.0% uncorrected genetic distance
• Morphometric Benchmarks: H. cairnicola reaches up to 49 mm SVL, featuring 13–15 longitudinal dorsal tubercle rows and 31–32 scale rows across the belly.

Official Responses and Scientific Perspectives

While formal statements from state forestry departments are pending, academic and institutional responses to the publication of H. cairnicola and H. koyaorum emphasize the critical importance of foundational taxonomy in modern conservation biology.

Senior researchers involved in the study stress that discovering new vertebrate species within populated and agricultural states like Telangana proves that India’s lesser-known micro-habitats still harbor vast, undocumented biodiversity.

"Cryptic species groups—such as the Hemidactylus brookii complex—have historically masked immense species diversity under single, broad taxonomic umbrellas," noted a team representative. "By integrating molecular genetics with classical morphology, we are finally peeling back these layers. What looks like a common house or rock gecko at first glance often turns out to be an evolutionarily unique lineage found nowhere else on Earth."

Conservationists from allied institutions have echoed these sentiments, pointing out that regional biodiversity documentation serves as the bedrock for environmental impact assessments, protected area planning, and legislative wildlife protections. Without knowing what species exist in a given ecosystem, policymakers cannot effectively safeguard them against anthropogenic threats.

Implications: Conservation Challenges and Future Outlook

The identification of Hemidactylus cairnicola and Hemidactylus koyaorum carries profound implications for reptile conservation, biogeography, and land-use planning in peninsular India.

1. Re-evaluating Biogeographic Endemism

The Deccan Peninsula is frequently perceived as a heavily altered landscape due to centuries of agriculture, livestock grazing, and urbanization. However, the discovery of micro-endemic reptiles restricted to specific rock outcrops in Nalgonda and Warangal suggests that rocky scrub forests act as evolutionary refugia. These habitats harbor specialized fauna adapted to extreme micro-climates, making them vital priorities for regional conservation frameworks.

2. Anthropogenic Pressures on Type Localities

Both new species are currently known exclusively from their restricted type localities. H. cairnicola, for instance, inhabits rocky outcrops nestled directly within agricultural matrices and areas adjacent to human habitations, including traditional Lambada settlements. While these geckos display a degree of resilience by utilizing man-made rock cairns and stone walls, they remain vulnerable to habitat degradation:

• Quarrying and Mining: The unregulated extraction of granite and building stone poses a direct, destructive threat to the rock-dwelling micro-habitats these geckos depend on for shelter and foraging.
• Agricultural Expansion: Clearing of scrub forests for farming fragments populations and restricts gene flow between isolated colonies.
• Infrastructure Development: Expanding road networks and rural electrification projects alter the micro-topography of these fragile ecosystems.

3. The Need for Expanded Herpetological Surveys

The authors of the study advocate for intensive, broader-scale surveys across neighboring districts in Telangana and adjoining states. Given that H. cairnicola and H. koyaorum were hidden within the H. brookii complex—a widely distributed group spanning diverse landscapes—it is highly probable that other undiscovered cryptic species are waiting to be unmasked in similar rocky terrains across peninsular India.

4. Policy and Conservation Action

To ensure the long-term survival of these micro-endemic geckos, conservationists recommend designating key rocky scrub forest patches as Ecologically Sensitive Areas (ESAs). Incorporating local communities—such as the indigenous and rural populations living alongside these habitats—into participatory conservation initiatives will be vital. Educating local stakeholders about the ecological role of insectivorous geckos can foster grassroots stewardship, ensuring that the Deccan Plateau’s newest scientific discoveries are preserved for generations to come.

For further details, read the complete research paper, titled "Two new cryptic species of Hemidactylus (Reptilia: Gekkonidae) allied to H. treutleri from Telangana, India," accessible via the European Journal of Taxonomy.