White-thighed surili
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. Description. Physical. The white-thighed surili are made up of a common surili build, ranging from around 41–69 cm tall and weighting 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, there tails – typically covered in dark fur – can extend roughly 58–85 cm. Compared to adults, infants are born with very light  fur with crosses of dark fur along their arms and back. Habitat. As an arboreal species, "P. siamensis" live in subtropical/tropical forest environments. They have been found to occupy moist lowland or swamp areas. In fact, they can even be inhabitants of terrestrial environments; for example, rural gardens. They can be located mainly on the Malay Peninsula, but are also found in Sumatra, as well as some parts of Thailand. Social Organization. The white-thighed surili live in small unimale-multifemale groups. After mating, females give birth to single infants to which the group of females care for. Due  to their arboreal lifestyle, reliance on detection of predators is vital. Male group members are able to call or display a distraction for predators to protect group members. Furthermore, this predator avoidance strategy is shown to be more effective with smaller groups. Taxonomy. "P. siamensis" is a member of old world monkeys. In fact, "P. siamensis" itself contains four subspecies: "siamensis, cana, paenulata", and "rhionis". Research suggests the white-thighed surili includes "P. natunae" (Natuna Island surili) as a subspecies; however both have been considered subspecies of "P. femoralis" (Banded surili) to which is argued"." Alternatively, research suggests three species  are endemic to Malaysia: "P. siamensis", "P. femoralis" and "P." "robinsoni" (Robinson's Banded langur). Through mitochondria DNA analysis, these 3 species are split into 2 separate clades: "P. femoralis" on its own, "P. robinsoni" and "P. siamensis" in the other. This was due to the sharing of unique nucleotides between "P. robinsoni" and "P. siamensis". There continues to be ongoing evolution of Robinson's banded langur and the white-thighed surili currently. Further research suggests "P. femoralis" to provide the basal lineage in the peninsular Malaysia of the "Presbytis". It is hypothesized that "P. femoralis" has diverged to form  P. robinsoni and "P. siamensis." Both species are monophyletic compared to "P. femoralis". The movement of "P. femoralis" to the Malaysian peninsula created the allopatric distribution. Further dispersal on the peninsula itself diverged "P. robinsoni" and "P. siamensis" through allopatric speciation. Overall, the taxonomy is constantly evolving and in need of continuing research. Threats to the Species. According to the IUCN Red List, the current status of the white-thighed surili is near threatened. Researchers say several "Presbytis" species are affected by logging activities, although not all of them are recognized on the IUCN red list. Conservation efforts for non -human primates - such as the white-thighed surili - are valued significantly. This species is seen in the public's eye as a value of science, genetics, forest sustainability, aesthetic, tourism, and a symbol of heritage. Researchers suggest continuing to familiarize the public with primate conservation concerns to enhance the willingness of participate in conservation efforts. In addition, only 30% of the forested area on the Malaysian Peninsula is legally protected from resource extraction, leaving 70% of forests vulnerable. More research on abundance, ecology and behavioural biology of the white-thighed surili is vital to creating better conservation management plans. An  alternative threat to this species has nothing to do with logging. Sometimes these primates may be kept as pets or used in the entertainment industry. Currently this species is listed under Appendix II of the Convention on International Trade in Endangered Species (CITES) to protect them from this. Moreover, education the public on illegal trade of primates as pets may combat the demand for the industry.