Deccan Traps — shaped by one of the largest ancient volcanic eruptions on the planet, and the mighty Western Ghats — form the majority of the topography of the state of Karnataka. Among the inhabitants of these amazing landscapes is a family of lizards that is often overlooked or misunderstood: shiny and snake-like in their movements, they are called ‘haavu-rani’ in Kannada (translating to ‘queen of snakes’). Of course, we are quite certain that no snakes were consulted when the title was decided.
Skinks belong to the family Scincidae and are amongst the most diverse families of lizards across the world. They are characterised by their glossy scales, elongated and dorso-ventrally flattened shape, and little to no neck, with the head seemingly fused with the rest of the body. They have snake-like overlapping scales: sometimes with a single ridge at the centre of each scale (called keels), or sometimes with multiple keels. A common sight, some species of skinks are widespread, and occupy similar habitats across the country.
To the untrained eye, most skinks appear to look alike. This is probably because of their quick movements (often disappearing no sooner than one sets their eyes upon them) and similar body structure. Skinks feed on a variety of insects and invertebrates, with the larger species preying on small lizards, frogs and even mice. Like geckos, their tails are fragile, and when threatened, will detach and wriggle, confusing the predator. They are capable of re-growing the tail.
Karnataka is home to 6 genera of skinks – Dasia, Eutropis, Kaestlea, Riopa, Ristella and Sphenomorphous – with at least 13 species. Ristella is endemic to the Western Ghats and Kaestlea is endemic to Peninsular India.
Dasia is an exclusively tree-dwelling genus of skinks that is distributed in South and Southeast Asia. They use their long claws to good effect in climbing trees. Because of their exclusively arboreal habits, they are secretive and not much is known about their natural history.
Blue-bellied Tree Skink (D. subcaerulea) is found in Karnataka around Kudremukh National Park, at elevations ranging from 300-1700 metres. It has a greyish brown back, with a pale blue neck and belly, and dark side-bands running along its body.
Eutropis is one of the most widespread genera of skinks in India. They have a relatively broad dorsum with well-developed limbs and tail. They are mostly terrestrial, but on occasions, can be seen hiding in tree holes or under the barks of large trees close to the ground. 5 species belonging to this genus are found in Karnataka – E. carinata, E. macularia, E. allapalensis, E. beddomei, and E. trivitatta. The first two species are also found almost all over India.
Common Grass Skink (E. carinata) is a large skink (growing up to 16 cm snout-to-vent and over a foot long including its tail). It has a bronze to olive coloured back, with brown bands extending from the side of its eyes up to its hind limbs. During breeding season, the males develop bright red patches around their jaw, belly and thighs.
Bronze Grass Skink (E. macularia) is a small, leaf-litter dwelling skink with a bronzed back and dark side-bands dotted with light speckles. It has been found to be occurring in forests as well as around human habitation. The males are particularly colourful during breeding season, with the red colouration of their throats extending up to their bellies.
Beddome’s Grass Skink (E. beddomei) is a dark brown coloured skink with five light-coloured stripes along its back. It is commonly distributed in plantations, secondary forests and plains.
Three-striped Grass Skink (E. trivittata) is a large, stout skink characterised by an olive-brown or greyish-brown body, with three broad, yellow stripes along its back until the base of its tail. It is found in deciduous, mixed, and scrub forests, between 500-1200 metre elevations.
Allapalli Forest Skink (E. allapalensis) is a small skink found in habitats with less human disturbance, such as moist and dry deciduous forests and rocky scrub forests. It closely resembles E. macularia due to it bronze-coloured back.
The genus Ristella, endemic to the wet regions of the Western Ghats, comprises of small skinks. They are often seen amidst leaf litter alongside streams in mid to high elevation moist forests. They are unique in possessing semi-retractile claws that resemble those of felines. This gives them their common name – Cat Skinks. One species, Beddome’s Cat Skink (R. beddomei), is found in Karnataka. An iridescent and colourful skink species with a characteristic green eye, this skink can be found in the wet forests from Dakshina Kannada till the Coorg plateau.
The genus Kaestlea, commonly known as Litter Skinks, is endemic to Peninsular India, including both the Western and Eastern Ghats. The etymology honours a German herpetologist, Prof. Werner Kastle. Long, tapering, shiny blue tails characterise the species of this genus. The bright colour of the tail is probably a defence mechanism – the twitching blue tail breaks off to distract the predator’s attention, while the skink manages to escape. Of the five currently known species of Kaestlea, only 1 is known from Karnataka – Beddome’s Litter Skink (K. beddomei). This species has a bronzed dorsum and black sides and is found in rainforest leaf litter.
Riopa is a widespread genus of skinks with an elongated body and reduced limbs. Four species are found in Karnataka: R. lineata, R. albopunctata, R. guntheri and R. punctata.
Lined Supple Skink (R. lineata) is a very slender and thin skink with a worm-like body. It can be recognised by its golden-yellow colouration with several dotted lines along its length.
Gunther’s Supple Skink (R. guntheri) is an endemic large-sized skink with a slim, elongated body, and is found in scrub forest habitats. It has a pale yellow body dotted with spots throughout its length.
Common Spotted Supple Skink (R. punctata) is the most widely distributed member of this genus. However, it is not often seen since it spends most of its time underground. It is characterised by a bronze coloured body with spots on every scale lining across its length. The juveniles have a bright orange to red tail, which fades in adults.
White-spotted Supple Skink (R. albopunctata) is a small, common skink found in human settlements. It has a shiny, reddish-brown back with 4 to 6 dotted lines running along its length. Breeding males display a yellowish wash along the ventro-lateral parts of their neck and fore-body.
Sphenomorphus is one of the most speciose genera of skinks, with more than 130 species. Within India, Sphenomorphus has an interesting distribution pattern, with four species being found in the north-east and one in the south. The one species isolated in the south is a Western Ghats endemic – Dussumier’s Litter Skink (S. dussumierii) – distributed in riparian forests. It has a dark brown to black body, dotted with yellow spots on its body and limbs, along with two broad, yellow stripes along its sides.
The impostors – Lacertidae
Lizards of the family Lacertidae are often confused with skinks due to their superficial resemblance – striped bodies and red tails. However, they have a distinct neck collar that separates the head from the body. Their much slender and longer limbs (compared to skinks) are built for running and climbing. One species – Leschenault’s Snake-eye (O. leschenaultii) – is found in Karnataka.