Presbytis siamensis
Silhouette: PhyloPic
In 3 days ~60% in a week ~90%
The white-thighed surili (Presbytis siamensis) is a species of primate from the family of old world monkeys (Cercopithecidae). This species lives arboreal amongst the sub-montane forests. It is endemic to the Thai-Malay Peninsula, the Riau Archipelago and Sumatra. In addition, the white-thighed surili contain four subspecies: siamensis (nominate), cana, paenulata and rhionis, are recognized here. Furthermore, they are characterized by the white patches located on the outside of their legs, which is what gives them their name. Additionally, they can be referred to as pale-thighed langur/surili. These primates are an important species for the diversity of forest environments in the Malaysian area.
The white-thighed surili are made up of a common surili build, ranging from around 41–69 cm tall and weighing 5–6.7 kg. Their slender build is covered with a brown-grey fur coat on their backs, with white fur covering their bellies and dark fur on their head. They are known for the white fur on the outsides of their thighs (giving them their name). Additionally, their tails – typically covered in dark fur – can extend roughly 58–85 cm. Compared to adults, infants... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Taman Negara National Park | 🇲🇾 Malaysia |
More parks will be added in future updates.
Possible
About 30% of wildlife watchers report a White-thighed Surili sighting in Taman Negara National Park on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 10th most-seen of the 22 mammals we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
January
In that month about 60% of wildlife watchers report a White-thighed Surili in Taman Negara National Park on a given day, against under 5% in March, May and November–December, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most White-thighed Surili sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Taman Negara National Park, in our data
Taman Negara National Park is the only park on Wallace's Line with enough records to rate White-thighed Surili sightings: about 30% of wildlife watchers there report one on a given day.
Same family: Cercopithecidae
The closest relatives of the White-thighed Surili that you can see in Taman Negara National Park (family Cercopithecidae, Old World Monkeys) are Crab-eating Macaque (about 60%), Dusky Leaf-monkey (about 30%) and Southern Pig-tailed Macaque (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the White-thighed Surili is recorded against all the mammals logged in Taman Negara 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.
