Reptiles of Sri Lanka
In a previous article I wrote about one set of reptiles, the turtles and tortoises. Today I have written about the lizards etc, which are more colourful reptiles.
LIZARDS: There are five ‘lizard like’ reptiles that I will deal with in this article. They are the Agamid lizards, Geckos, Chameleons and Monitor Lizards. The agamid lizards are called Katussa in Sinhala and Onnan or Karata in Tamil.
The Gecko found in urban dwellings is called Huna in Sinhala and Palli in Tamil. The Geckos found in the rural areas and the jungles are called Kimbul Huna in Sinhala and Pal Li in Tamil.
The land monitor (Varanus bengalensis) is called a Thalagoya in Sinhala and Udumbu in Tamil. The water monitor (Varanus salvator) is called a Kabaragoya in Sinhala. There are very few Tamil names in use for most of the lizards in Sri Lanka.
In this article I sometimes refer to relict species. A relict species is one where the genera are confined to a particular country. Anthropogenic is where a species lives in human habitations.
A fossorial species is one that lives in the ground. A sub fossorial species is one that lives under rocks, stones, logs etc. Crepuscular means active at dawn and dusk.
They are also called Chisel-toothed lizards. Sri Lanka has 17 species of agamids, 14 of which are endemic to the island. Most of these lizards have a spiny ridge on the top of their backs.
There are seven 7 species of Calotes lizards in the country. The most common are the Common Garden Lizard (Calotes versicolor) called Gara Katussa in Sinhala and the Green Garden Lizard (Calotes calotes) called Pala Katussa in Sinhala.
These species are seen in a wide variety of habitats, including human habitations, throughout the island up to about 4,500 feet. They are both mainly arboreal in that they are on trees and shrubs etc. [WL]
The rarest species is the Crestless Lizard called Kondu Datirahita Katussa in Sinhala. It is a species endemic to Sri Lanka. The Crestless lizard (Calotes liocephalus) closely resembles the Green Garden Lizard (Calotes calotes) except for the absence of spines on its back. This species is confined mainly to the Knuckles region.
The Painted-lip Lizard (Calotes ceylonensis), is called Thola-visithuru Katussa in Sinhala is also endemic to the island. This is an arboreal lizard, which is quite colourful. It is found in the monsoon forests and home gardens of the dry zone.
The Whistling Lizard (Calotes liolepis) is called Sivuruhandalana Katussa in Sinhala. It is also endemic. This lizard is found in the wet zone and in some parts of the intermediate zone. It’s an endangered species and is one of the very few agamids, which can produce a whistling sound.
The Black-lipped or Black cheeked Lizard (Calotes nigrilabris) can also make this whistling sound. It is called Katakalu Katussa in Sinhala.
This species is endemic and is found only in montane forests above 3000 feet. It is sub-arboreal in that it is found on the ground and also on trees and shrubs, but more on the ground.
The Sri Lankan Kangaroo Lizard (Otocryptis wiegmanni) is endemic. It is called Pinum Katussa in Sinhala. It occurs throughout the wet zone. Another lizard from this genus was found recently and named (Otocryptis nigristigma). It is also endemic but restricted to the dry zone.
These species gets their name because they are able to run very fast on the two hind legs keeping the front legs lifted up. Both species occupy a wide range of habitats ranging from undisturbed rain forests to highly developed agricultural lands and home gardens.
The males have a large dewlap or gular sac under their throats, which is thought to play a major role in attracting females during the mating season.
The Pigmy Lizard (Cophotis ceylanica), called Kurubodiliya in Sinhala, is endemic. It is a rare agamid inhabiting the moss covered tree trunks in mountains and cloud forests above 6000 feet. It is one of the slowest moving reptiles in the country and can be easily identified by the irregular shaped body scales and curled prehensile tail. The Pigmy Lizard is a relict species.
The Fan-throated Lizard (Sitana ponticeriana) is called Pulina Talikatussa, Vali Katussa in Sinhala. It is restricted to warm lowland scrublands, particularly the drier coastal areas.
It is similar to the Kangaroo Lizard in appearance but differs in the throat colour of the males, which is blue and white against red and yellow in the kangaroo species.
There are five species of horned lizards of the genus Ceratophora. The males of all species carry elongated appendages at the end of their noses, which gives them their name. The Rhino-horned Lizard (Ceratophora stodarrtii), named Kagamuva Angkatussa in Sinhala, is endemic.
It is found in the cloud forests of the central massif, in Horton plains, Peak Wilderness, Haputale etc. It has a sharp ‘horn’ comprising of a single scale, whereas the horn of the Leaf-horned Lizard (Ceratophora tennentii) is a flat leaf-like one.
The Leaf-nose Lizard (Ceratophora tennentii) called Peti Angkatussa in Sinhala, is endemic. It is arboreal and restricted to the Knuckles range, where it is also found in forests under planted with cardamom.
The purely ground dwelling Rough-horned Lizard (Ceratophora aspera) in Sinhala Raluang Katussa, is endemic. It is found in the Diptherocarpus and secondary forests in the South wet zone belt. There are two new species of Ceratophora. One is Erderlen’s Horned Lizard (Ceratophora erdeleni) called Erdelenge Angkatussa in Sinhala. It is endemic and named after Walter Erderlen, who discovered it.
The other is Karunaratne’s Horned Lizard (Ceratophora karu), named after the late P. B. Karunaratne one of Sri Lanka’s foremost herpetologists. Called Karunaratnege Angkatussa in Sinhala, it is also endemic. Both species are restricted to the Morningside Forest Reserve and in Deniyaya at the Eastern side of Sinharaja. Ceratophora karu is one of the rarest agamids of the country.
Hump-nosed Lizard (Lyriocephalus scutatus) is called Gatahombu Katussa, Karamal Bodiliya in Sinhala. It is endemic. This species is restricted to elevations below approximately 4800 feet, where it inhabits forests and the heavily planted home gardens, mainly in the wet zone and in few places of the intermediate zone.
It’s a slow moving species and has both arboreal and terrestrial habits. A unique defensive posture of this species is the display of the deep red colour of the mouth.
The two species of Varanids are the largest lizards found in Sri Lanka. They are the Land Monitor (Varanus bengalensis) and the Water Monitor (Varanus salvator).
The land monitor is found mainly in the lowland dry zone, but can go up to 1500 feet. It is very widely distributed. It lives in a varied range of habitats from arid desert fringes to rainforests, but is most common in farmlands (particularly the coconut plantations) and dry, open forests.
Land monitors reach a maximum snout to vent length of about 140 cm in Sri Lanka and large specimens can weigh over 10 kg. Land monitors spend the nights in burrows, where their body temperature decreases.
The following morning they raise their body temperature by basking in the sun before commencing any activity. Hence they are rarely active early in the morning.
The water monitor does not usually venture far from water. The land monitor is an excellent climber. Even large adults can go up vertical tree trunks with ease. They are reported to be agile in that can even stalk and capture roosting bats.
Despite their large size, these lizards get most of their nutrition from tiny prey and feed mainly on beetles, grubs, scorpions, snails, ants and other small invertebrates, which are consumed in enormous numbers. Hence they are important biological controllers of agricultural pests.
In contrast, the Water Monitor (Varanus salvator) is one of the most widespread lizards in the country and is distributed from the coastal plains up to some parts of the second peneplain in the wet zone. Varanus salvator can attain total lengths of 3 meters, thus it is the second largest lizard in the world, second only to the Komodo dragon (Varanus comodonensis) of the Indonesian islands.
The Water Monitor eats a large variety of small animals that it believes it can consume. Among some of the common prey are: birds and their eggs, small mammals (especially rats), fish, lizards, frogs, snakes, juvenile crocodiles, tortoises and turtle eggs.
The primary hunting technique used by Varanus salvator, as well as by other monitors, is characterized by ‘open pursuit’ hunting, rather than stalking and ambushing. While hunting for aquatic prey, Varanus salvator can remain submerged for up to 30 minutes. Varanus salvator is semi-aquatic and has a wide range of habitats. They are frequently seen on river banks and in swamps.
But it also inhabits anthropogenic habitats such as ditches in towns etc. The flesh of the water monitor is highly poisonous and not consumed by man. However the land monitor is widely killed for food and for its skin. Both monitors are predators of agricultural pests and are efficient scavengers in the environment.
The Chameleon (Chameleo zeylanicus) is called Bodiliya in Sinhala. It is a rare reptile restricted to the scrub jungles and forests of the Northwestern and Northern dry zone region, with only very few scattered records from Tabbowa, Mankulum, Jaffna, Marichchukaddi, Puttalam and Wilpattu NP.
It is largely arboreal and only rarely descends to ground, and that to mate or lay eggs. The highly prehensile tail facilitates its arboreal habits. Prehensile in that it can be curled round a branch or a twig and will ensure that the chameleon will not be dislodged.
The Chameleon is a very slow moving species. It has the ability to rotate its eyes independently. The tongue can be ‘shot out’ to a distance almost equal to the length of its body in order to catch insects, which it feeds on.
The tongue has an adhesive substance onto which the insects etc. stick on. The chameleon has the ability to change the colour of its skin very quickly. The known habitat of the species in the country is largely destroyed due to deforestation and chena cultivation.
Geckos are considered the most primitive living saurian in Sri Lanka. Ferguson (1877) recorded sixteen species of geckos in his book ‘Reptile Fauna of Ceylon’, which is the first comprehensive and fully annotated list of the Sri Lankan herpetofauna.
Subsequently Deraniyagala (1930) and Taylor (1953) described 15 species in eight genera and 20 species in eight genera, respectively. Again in 1953, Deraniyagala increased the number of species + subspecies to 19 in (Volume II of the Coloured atlas of vertebrates of Ceylon).
In recent literature Kelum Manamendra-Arachchi in 1997, considered the Sri Lankan geckos to be consist of 19 living forms, but Anslem de Silva in 2001, lists 20 taxa. With the latest description of five new Cyrtodactylus species in 2005, the total number has risen to 25.
The gecko genus Cnemaspis is the only genus, which contains purely diurnal geckos in Sri Lanka, thus is commonly called ‘Day geckos’.
The species The Kandyan Day Gecko (Cnemaspis kandiana), Rough-bellied Day Gecko (Cnemaspis tropidogaster), Jerdon’s Day Gecko (Cnemaspis jerdonii scalpensis) and Dwarf Day Gecko (Cnemaspis podihuna) are found here.
The latter two are endemic. These geckos are crepuscular, usually found on rock faces, large trees and occasionally under stones and logs. They are more often found in pairs and some species lay two fused eggs separately but others do communal nesting.
Cnemaspis podihuna is the smallest gecko in the country and is recorded from only a few widely separated localities. The species has an ability to climb smooth surfaces, such as glass, which is uncommon in other Cnemaspis species.
The endemic Sri Lankan Golden Gecko (Calodactylodes illingworthorum) is distributed in a few widely separated locations in the southeast dry zone. It inhabits large boulder-dominant rock faces and caves.
It’s a social gecko usually found in groups of 3-11 animals, and is nocturnal in behaviour. Communal nesting places are used and several females revisit them each season.
Till recently, it was believed that the genus Cyrtodactylus had only one species, the endemic Great Forest Gecko (Cyrtodactylus fraenatus), which was the second largest gecko species in the country. The largest gecko is Hemidactylus maculates.
Now the species have been split in to six (five new species) and they have restricted distributions i.e. C. cracens and C. subsolanus in Sinharaja, C. Edwardtaylori from Namunukula, C. Ramboda in North-Western slopes of the central hills and C. Soba in Knuckles range.
The earlier C. Fraenatus is distributed in the hills around Kandy. They inhabit a wide range of habitats including houses, caves, large trees, wall crevices etc. These nocturnal geckos are comparatively slow and inactive in behaviour.
The Spotted Bow-finger Gecko (Geckoella triedra) is a ground dwelling species, mainly restricted to the wet zone rain forests.
However, it has also been found in the vicinity of human settlements. Its favourite niches are leaf litter and tree buttresses. Usually two eggs are stuck to the underside of large rocks. It’s a slow moving, terrestrial species.
The name ‘Hemidactylus’ meaning ‘Half fingered’ (Hemi=half, daktylos=toe) comes from the longitudinally bi-divide lamella in the front half of the fingers. It is the largest gecko genus in the country and is represented here by seven species, three of which are endemic to the island.
All Hemidactylus species in the country can produce a sound, which differs according to the species. Other than for Hemidactylus scabriceps whose status is unclear, all other species in the country have been found inside or within human habitations.
The slender-bodied, slow moving, Slender Gecko (Hemiphyllodactylus typus) is an eccentric species that can be easily identified by its lean appearance. The species can be considered rare in the wild, but though uncommon occurs also inside houses mainly in the lowland wet zone.
The adults are dull coloured but the juveniles are very colourful. The Scaly-Fingered Gecko (Lepidodactylus lugubris) is a buff-yellow coloured gecko, which moves slowly when compared with the other species, even when handling. It is often seen with its tail curled.
The Four-clawed Gecko (Gehyra mutilata) is a soft-bodied gecko found in houses almost everywhere in Sri Lanka and can be easily identified by the flat tail in the shape of a ‘carrot’. This species can mutilate itself by dropping a part of its tail when caught. The tail grows again.