Craspedocephalus borneensis
Silhouette: Vijay Karthick · PhyloPic
In 3 days ~40% in a week ~70%
Craspedocephalus borneensis, commonly known as the Bornean pit viper, is a venomous pit viper species endemic to the island of Borneo. No subspecies are currently recognized. Scalation includes 19–21 rows of dorsal scales at midbody, 152–180 ventral scales, undivided anal scale, 45–58 divided subcaudal scales, and 8–11 supralabial scales.
Its coloration varies. Individuals may be brown with darker brown saddles, or light brown with a few darker markings, or even bright yellow with darker markings. Adults may attain 83 cm (33 in) in snout-vent length (SVL).
Craspedocephalus borneensis is found on the island of Borneo (Brunei, Kalimantan, Sabah, Sarawak) as well as in the Natuna Islands. The type locality given is "Sarawack" (= Sarawak, Borneo). It is found in forests below an altitude of 1,130 m (3,710 ft). Even though the tail is prehensile, adults are usually on the forest floor. Juveniles may be in low vegetation.
Craspedocephalus borneensis preys upon small rodents and small birds. Whether this species of Craspedocephalus lays eggs or bears live young is as yet unknown. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Kinabalu Park | 🇲🇾 Malaysia | |
| 2 | Sepilok | 🇲🇾 Malaysia |
Possible
About 20% of wildlife watchers report a Borneo Pit Viper sighting in Sepilok on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 19th most-seen of the 34 reptiles we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
April
In that month about 30% of wildlife watchers report a Borneo Pit Viper in Sepilok on a given day, against under 5% in October to February, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Borneo Pit Viper sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Among the best
Of the 2 parks where we can rate Borneo Pit Viper sightings, Sepilok ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Kinabalu Park (Malaysia, about 20%).
GBIF citizen-science records
It is estimated from how often the Borneo Pit Viper is recorded against all the reptiles logged in Sepilok (13 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
