Lowland Hump-nosed Pit Viper/පහතරට මූකලන් තෙලිස්සා[Pahatharata Mukalantelissa] (Hypnale zara)

An endemic snake restricted to the lowland rain forests of the south-western wet zone up to foot hills of the central highlands.  It is a nocturnal snake and during the day time stay hidden under decaying logs and leaf litter on the forest floor. Maduwage K. et al. recorded of a rare occasion of observing this snake on a shrub up to about 60cm above the forest floor. Furthermore according to them Lowland Hump-nosed Pit Viper is absent in anthropogenic habitats. Above specimen was photographed on a banana shrub - considerable height above the ground- But habitat can't be considered as a primary forest though entirely not a home garden ( 6°22'24.18"N,  80°27'8.22"E). Location -though sort of anthopogenic habitat- is very close to the Gin river as well as Sinharaja forest.

Maduwage Kalana, Silva, A., Manamendra-Arachchi, K.& Pethiyagoda, R. 2009 A taxonomic revision of the South Asian hump-nosed pit vipers (Squamata: Viperidae: Hypnale) Zootaxa 2232: 1–28 pp.

Merrem’s Hump-nosed Pit Viper/පොලොන්තෙලිස්සා/කුණකටුව/ගැට පොලගා[Polon Thelissa/Kunakatuwa/Gata Polaga] (Hypnale hypnale)

Common venomous terrestrial snake found in anthropological habitats and plantations (Especially tea, coconut and rubber plantations) from coastal areas up to about 600m of the central hills. More abundant in the south-western wet zone than in the northern and eastern dry lands. However it appears to be absent in undisturbed forests in Sri Lanka.  It is a nocturnal snake and during the day time rest under stones, logs and among leaf litter sometime with its head keep at an angle of 45 degrees to its body resembling a dry leaf. When  disturbed it flattened its body, forms it into ‘S’ shaped loops, often vibrates the tail and lashed out. Rapid tongue protrusion has been observed too.  It preys on skinks, shrews, geckos, frogs and rodents. Instances of feeding on reptile eggs and snakes are also observed. Merrem’s Hump-nosed Viper is responsible for the highest incidents of snake bites in Sri Lanka (~27%) with occasional fatalities though its venom is considered as moderate.

තිත් පොළඟා/දාර පොළඟා[Thith Polonga/ Dhaara Polaga]/Russell’s viper(Daboia russelii)

Russell’s viper is a highly venomous ground-dwelling snake with wide distribution from sea level to mid-hills of about 1500m a.s.l. But relatively common in dry zone shrub lands and grass lands. It is responsible for large number of human mortalities in agricultural districts since they are common in such anthropogenic habitats due to abundant of its main prey (i.e. rats).Other than small mammals like rodents its diet consists also of lizards, frogs and sometimes birds. Russells’s viper has very remarkable loud hiss emitting through its nostrils when threatened. P.E.P.Deraniyagala(A colored atlas of some vertebrates from Ceylon – Vol 3) mentions that wild specimens have a strong odor resembling that of crushed bed bugs (S: Makunu ganda) or of the flowers of the Mi tree(Madhuca longifolia) but does not emit when in captivity. He also records that it is frequently killed and eaten by the cobra (Naja Naja). This snake can be easily identified by having a light pink or white V shaped mark on head and a row of sub circular dark brown blotches of about 22-24 along vertebral region and two similar but with smaller blotches of rows beside lateral one.
Colour Guide to the Snakes of Sri Lanka

පලා පොළඟා[Palaa Polaga]Green Pit Viper (Trimeresurus trigonocephalus)

Green Pit Viper is a moderately venomous endemic snake to Sri Lanka. It is arboreal and nocturnal, occasionally descending to the ground in search of food comprises of frogs, small mammals and birds. This sluggish pit viper is usually encountered on low shrubs during morning hours. It is widely distributed in all three climatic zones of the island except higher hills and arid zones while relatively much common in wet zone grasslands and rain forest areas and occasionally in plantations. It produces live young most of the time during months of June-July. When threatened vibrate its tail and lashes out to bite seldom with hissing sound.