Lowland Hump-nosed Pit Viper

The Lowlands Hump-nosed Pit Viper (Hypnale zara) is a venomous snake found only in Sri Lanka’s wet zone rainforests and the lower slopes of the central highlands, between 60–600 meters above sea level. It is closely related to the more widespread Hypnale hypnale but can be identified by its less upturned snout and more varied body colors. Its head carries small wart-like scales at the tip of the snout, with keeled body scales and 134–157 ventral scales. The body color ranges from yellowish brown to dark brown, sometimes reddish, marked with paired triangular blotches along the back. A dark band runs across the eye and cheek, while the underside is paler, often grayish.

This species is mostly nocturnal, hiding during the day under leaf litter and fallen logs, and sometimes climbing low shrubs at night. Unlike other snakes, H. zara gives birth to live young (ovoviviparous), with litters ranging from 5–8 offspring already showing adult coloration at birth. It is strictly a forest-dwelling species, not seen in home gardens or disturbed habitats, making it vulnerable to habitat loss. Although venomous, it is a small-bodied pit viper and prefers to remain hidden, playing an important ecological role in controlling small forest animals like frogs and lizards.