Crawling back to sight: skink found after century-long obscurity
A cryptic, elusive, and forgotten reptile, India’s Rurk’s Cat Skink has shown itself after a lapse of a whopping 175 years since its original description and 90 years since its last sighting. In one of the world’s longest games of hide-and-seek, a scientist working on southern Indian reptiles illustrates this little-known species in life for the first time from the southern Western Ghats.
Scales of uniqueness
A small, leaf-litter-dwelling lizard that calls the dense forests of the Western Ghats its home, the Rurk’s Cat Skink Ristella Rurkii belongs to the family Ristellidae, the onlyfamily that is to the Indian subcontinent. It was, in fact, the first species to be described from its genus in as early as 1839. Apart from having a pale brown shining crown and back, its uniqueness lies in being the only smooth-scaled reptile in its genus and in having retractable claws, a peculiarity that also gives it its common name.
Forgotten in cold blood
Despite being long-known and the senior-most of the genus, the Rurk’s Cat Skink has remained obscure to science for as long as 175 years since its first discovery. For the longest time, the skink was misidentified as being from northern India and also excluded from various reptile catalogues. Added to its cryptic appearance and elusive habits, these scientific mishaps disoriented subsequent attempts at documenting the species. The sole published information reporting a collection of the species was that from 1927 from the Western Ghats.
It is then no surprise that this group ranks as one of the most poorly-studied lizards in the Indian peninsula and has been regarded as Data Deficient. Even basic information regarding its, distribution, and still stands unknown. In a broader sense, knowledge of its genus itself is rather scanty.
During fieldwork in the southern Western Ghats in January 2015, S.R. Ganesh, ain Chennai Snake Park, spotted the skink from the localities in and around the Kodaikanal Wildlife Sanctuary. From 60 man hours of survey, a total of three individuals of the species — a juvenile, a male, and a female — were found. The individuals were directly examined and compared with preserved specimens to establish unambiguous species-identification. Two near-term eggs were visible through the abdomen of the female, indicating that January falls within the breeding season of the species, at least in this region.
As the present finding agreed in morphology with that of the preserved specimens and was from a previously known, verified locality, its veracity is clearly backed up. Pending further reliable reports, Rurk’s Cat Skink should currently be considered as endemic to the southern Western Ghats, a fact that has got a direct bearing on its conservation status.
► Refinement of the threat status evaluation of the Rurk’s Cat Skink is recommended.
► Further targeted surveys should continue to discover more populations of this species.
► A broad taxonomic revision of all the species in the genus Ristella is direly needed.
Ganesh, S.R. (2018). The rediscovery of Rurk’s Cat Skink Ristella rurkii Gray, 1839 (Reptilia: Ristellidae) with remarks on distribution and natural history. Journal of Threatened Taxa 10(10): 12376–12381; https://doi.org/10.11609/jott.3922.214.171.12476-12381