Trimeresurus gunaleni
Silhouette: Steven Traver · PhyloPic
In 3 days ~50% in a week ~80%
Trimeresurus gunaleni, also known as Gunalen's pitviper, is a species of pit viper endemic to Sumatra (Indonesia). It is venomous. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gunung Leuser National Park | 🇮🇩 Indonesia |
More parks will be added in future updates.
Possible
About 20% of wildlife watchers report a Gunalen's Pitviper sighting in Gunung Leuser National Park on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 18th most-seen of the 47 reptiles we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
March
In that month about 40% of wildlife watchers report a Gunalen's Pitviper in Gunung Leuser National Park on a given day, against under 5% in January, May–June and October–November, the lowest months. That is one of Gunung Leuser National Park's driest months, with about 180 mm of rain against 700 mm in September.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Gunalen's Pitviper sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Gunung Leuser National Park, in our data
Gunung Leuser National Park is the only park on Wallace's Line with enough records to rate Gunalen's Pitviper sightings: about 20% of wildlife watchers there report one on a given day.
Same genus: Trimeresurus
The closest relatives of the Gunalen's Pitviper that you can see in Gunung Leuser National Park (genus Trimeresurus, Asian Lanceheads) are Hagen’s Pitviper (about 20%) and Sabah Bamboo Pitviper (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Gunalen's Pitviper is recorded against all the reptiles logged in Gunung Leuser National Park (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.
