Mandai Broadwalk : 04-01-25

Cercopithecidae is the taxonomic name for the family of Old World monkeys. The name translates to "elongated ape". There are twenty-four genera and 138 species recognized, making it the largest primate family.

Old World monkey genera include baboons (genus Papio), red colobus (genus Piliocolobus) and macaques (genus Macaca). Common names for other Old World monkeys include the talapoin, guenon, colobus, douc (douc langur, genus Pygathrix), vervet, gelada, mangabey (a group of genera), langur, mandrill, drill, surili (Presbytis), patas, and proboscis monkey.

Trachypithecus (derived from Greek τραχύς, trachýs meaning "rough" and πίθηκος, píthekos meaning "monkey") is a genus of Old World monkeys containing species known as lutungs, langurs, or leaf monkeys.

Their range is much of Southeast Asia (northeast India, Vietnam, southern China, Borneo, Thailand, Java, and Bali).

Formerly there were two subspecies of Trachypithecus auratus recognized : Eastern Javan langur or spangled ebony lutung, Trachypithecus auratus auratus and the Western Javan langur, Trachypithecus auratus mauritius.

Roos et al., 2008, elevated T. a. mauritius to a separate species as Trachypithecus mauritius. East Javan langurs and West Javan langurs are subspecies of the Javan langur, a type of monkey that lives in Indonesia. They are similar in appearance, but have some differences in behavior and habitat. The two subspecies of this monkey are fairly similar in appearance and are geographically separated, males and females are both usually glossy black, although the females pale, yellowish-white patch around the pubic area.

Juveniles of both subspecies are orange in color. The nominate subspecies Trachypithecus auratus auratus has a rare morph that does not lose its juvenile coloration when it matures, instead, the coloration darkens slightly, with yellow tinges on its sides, limbs, and around its ears, and a black tinge on its back.

Trachypithecus auratus the East Javan langur, also known as the ebony lutung, Javan langur or Javan lutung, is an Old World monkey from the Colobinae subfamily. Trachypithecus auratus is an endangered Old World monkey endemic to Java, Bali, and Lombok in Indonesia, It is a medium-sized colobine monkey with a glossy black coat and brownish tinges on the legs, sides, and sideburns, though juveniles are born with bright orange coats that darken with age. The Latin word auratus in its scientific name means "golden" and refers to a less common color variant. The common name golden langur refers to a different species.

Some individuals retain a rare golden morph into adulthood, reflected in the species name "auratus," meaning "gold" in Latin. Adults have long, lanky limbs, opposable thumbs and big toes, and extremely long, non-prehensile tails measuring up to 98 cm, while body length averages around 55 cm. Males are slightly larger than females, and females often have a pale yellow patch around the pubic area.

The East Javan langur (Trachypithecus auratus) inhabits the interior and peripheral areas of rainforests. This primate is diurnal and arboreal. Its diet is primarily herbivorous, eating leaves, fruit, flowers, and flower buds, although it also eats insect larvae. As with other colobines, it has evolved a specialised stomach to digest plant material more efficiently. This species also has enlarged salivary glands to assist it in breaking down food.

In appearance, spangled ebony langurs or east javan langur (Trachypithecus auratus) generally have glossy black coats with brownish tinges on their legs, sides, and sideburns. Like many langur species, infants are born with bright orange coats that darken to black as they age.

Uniquely, some spangled ebony langur or east javan langur (Trachypithecus auratus) individuals carry a rare morph and they do not lose their juvenile coloring as they mature. Instead, their adult pelage remains golden, although slightly darker than that of infants, with yellow tinges on their sides, on their limbs, and around their ears, and with a black tinge on their backs.

Their scientific name recognizes this morph in the word auratus, which means “gold” or “having the color of gold” in Latin. The East Javan langur (Trachypithecus auratus), also known as the ebony lutung, Javan langur or Javan lutung, is an Old World monkey from the Colobinae subfamily. It is most commonly glossy black with a brownish tinge to its legs, sides, and "sideburns".

Trachypithecus auratus the East Javan langur or Spangled ebony langurs are Old World primates in the Colobine, or leaf-eating, family. They are endemic to isolated forest fragments of East Java, as well as the small islands of Bali, Lombok, Palau Sempu, and Nusa Barong.

The East Javan langur inhabits the interior and peripheral areas of rainforests. This primate is diurnal and arboreal. Its diet is primarily herbivorous, eating leaves, fruit, flowers, and flower buds, although it also eats insect larvae.

As with other colobines, it has evolved a specialised stomach to digest plant material more efficiently. This species also has enlarged salivary glands to assist it in breaking down food.

The West Javan langur (Trachypithecus mauritius) is an Old World monkey from the Colobinae subfamily. It was formerly considered a subspecies of Trachypithecus auratus until it was elevated to a separate species by Roos and Groves. It is listed as vulnerable by IUCN .

Its range is restricted to the island of Java west of Jakarta currently restricted to Ujung Kulon National Park, Muara Angke Wildlife Reserve and Muara Gembong due to industrial development, habitat fragmentation and the disconnection of protected areas. They are known to eat the leaves and fruits of Sonneratia in mangroves.

Langurs primarily have a herbivorous diet, consisting mainly of leaves, fruits, flowers, and occasionally seeds and bark. Their digestive system is adapted to break down tough foliage, allowing them to efficiently process their food. Langurs play a crucial role in seed dispersal and the health of their habitats by foraging for a variety of plant materials.

Monkeys are omnivores with highly varied diets that include mix of plant-based and animal-based foods, making them omnivores. Their diet typically includes fruits, leaves, seeds, nuts, flowers, nectar, and tree sap, as well as insects, eggs, small birds, lizards, and other small animals depending on the species and environment. Some species, like the gelada, are primarily herbivorous, feeding mainly on grass, while others, such as capuchins, consume both plant matter and insects

Langurs and monkeys are both primates, but they are different species with different diets, habitats, and behaviors. Langurs eat leaves, buds, bark, seeds, and some fruit. They have complex digestive systems with multi-chambered stomachs that help them break down cellulose. They live in multi-male and multi-female groups in forests, mountains, semi-arid areas, and dry grasslands.

Monkeys. New World monkeys eat mostly fruit, while Old World monkeys live in Africa and parts of Asia. Baboons and some other monkeys live on the ground in grasslands or rocky areas.

New World monkeys live in the tropical regions of Central and South America, while Old World monkeys live in Africa and parts of Asia. 

Most monkeys live in trees in rainforests. Monkeys are highly intelligent and communicative, with facial muscles that allow them to communicate with facial expressions. Some species can be trained to act as service animals.

Phylum : Chordata

Class : Mammalia

Order : Primates

Suborder : Haplorhini

Infraorder : Simiiformes

Family : Cercopithecidae

Genus : Trachypithecus

Species group : Trachypithecus cristatus group

Species  : T. auratus

Binomial name : Trachypithecus auratus

É. Geoffroy, 1812

Trachypithecus obscurus, the spectacled langur, or spectacled leaf monkey is a species of primate in the family Cercopithecidae. It is found in Malaysia, Myanmar and Thailand.

The different subspecies are differentiated by the color of their fur. These monkeys are very docile and calm in contrast to other monkeys. They have large white colored circles around their eyes which give an appearance of a spectacle, because of this it is also name the Spectacled Langur.

This animal has also white colored patches of fur around its mouth and stomach while the rest of the fur has a gray to brownish color. The color of its fur varies along the 7 subspecies. The primate consists of short hind and forelimbs and has stronger fibula and femur compared to other species of langur. The tail is not adapted for holding and grasping it is more for balancing.

​The newborn dusky leaf monkeys are orange or yellow in color with a cute pink face. Within 6 months the color of the fur changes from orange to grey/brownish. The length of the body falls in the range of 42-61cm. Including its tail, they measure up to 50-85cm.

Male monkeys are heavier and larger than their female counterparts. These cute looking monkeys are arboreal and spend most of their time on trees. They move around leaping and climbing by quadrupedal motion around the forest and they prefer dwelling on tall trees in dense forests.

Dusky langurs feed on young leaves and occasionally on fruits, the seeds of which are then dispersed throughout the forest. This makes them important to the reforestation and biodiversity of their ecosystem. Dusky langurs possess a repertoire of vocalizations, postures, and tactile behaviors which they use to communicate with one another.

Vocalizations of males are typically more robust than that of female dusky langurs. Females emit similar calls as their male counterparts, but they use a softer tone. Both male and female dusk langurs are considered sexually mature between 3 or 4 years of age.

Breeding can occur throughout the year; however, most births occur between January and March. Females usually give birth to a single infant, but occasionally to twins (only one usually survives) after a gestation period of 145 days. Interval between births is typically about 2 years.

Dusky leaf monkey (Trachypithecus obscurus) inhabits a variety of forest types, including primary and secondary forests, montane, riparian, and disturbed forests, and can also adapt to human-modified areas like plantations and urban gardens. Dusky leaf monkeys live in troops that separate into sub-groups while scavenging for food.

Trachypithecus obscurus is a social, arboreal primate with distinctive facial markings, a primarily leaf-based diet, and complex social behaviors, they often rest at high elevations forest canopy to feed on their foraged vegetation. 

According to the IUCN, the dusky leaf monkey's population is declining due to habitat loss, poaching, and anthropogenic land use, which prompted the IUCN to classify the species as endangered in 2015.

Class : Mammalia

Order : Primates

Suborder : HaplorhiniInfra

order : Simiiformes

Family : Cercopithecidae

Genus : Trachypithecus

Species : T. obscurus

Binomial name : Trachypithecus obscurus

(Reid, 1837)

The surilis are a group of Old World monkeys in the genus Presbytis. They live in the Thai-Malay Peninsula, on Sumatra, Borneo, Java and smaller nearby islands. Besides surili, the common names for the monkeys in the genus also sometimes use the terms "langur" or "leaf monkey."

Surilis are rather small, slimly built primates. Their fur at the top is brown, grey, black, or orange, and at the lower surface whitish or greyish, sometimes also orange, with some species having fur designs at the head or at the hips.

Their German name of Mützenlanguren ("capped langurs") comes from the hair on their head, which forms a tuft. They differ from the other langurs by characteristics in the shape of their head (particularly the poorly developed or absent brow ridges, and the prominent nasal bones), in the teeth, and by the size of their small thumbs. Surilis range in adult length from 40 to 60 cm (with a 50- to 85-cm-long tail) and a weight of 5 to 8 kg.

Diurnal forest dwellers, they spend nearly their entire lives in the trees. They live in groups of up to 21 animals (typically 10 or fewer animals in most species) consisting of a male, several females, and their young. A few species have been observed in monogamous pairings (particularly the Mentawai langur), although this might be a reaction to the decrease of their habitat. Lone males and all-male groups have also been reported. The groups are hierarchically developed, with intergroup communication that is both vocal and postural.

The surilis' diet consists of leaves, fruits, and seeds. Gestation time is 5–6 months, and births are typically of single young. Newborn animals are white colored and have a black strip at the back, although some have a cross-shaped mark. By one year old, the young are weaned and at an age of 4–5 years, they are fully mature. The typical life expectancy in the wild remains poorly known for most species, but captive Sumatran surilis have lived more than 18 years.

The banded surili, also known as the banded langur or the banded leaf monkey, and sometimes known as Raffles’ banded langur, once roamed the tropical jungles from the southern peninsulas of Myanmar and Thailand to the islands of Singapore and Sumatra. Changes in their environment caused by humans have not only reduced the size of their range considerably but have also fragmented it severely.

Today, three subspecies of banded surilis inhabit pockets of their former range in small isolated bands. These are Raffles’ banded langur (P. f. femoralis), the East-Sumatran banded langur (P. f. percura), and Robinsons’ banded langur (P. f. robinsoni).

North, along the Malay Peninsula and into Myanmar, Thailand, and Burma, Robinsons’ banded langurs are believed to be the most abundant population of banded surilis.

In Indonesia, on the island of Sumatra, East-Sumatran banded langurs dwell in the jungles between the Rokan and Siak rivers. Members of Raffles’ banded langur live in the peat forests of the Malay Peninsula and among the dwindling swampy rainforests of Singapore.

Even among the three subspecies, groups tend to be isolated from one another by the ever-increasing encroachment of humans, which frequently causes gene pools to stagnate wherever the species manages to find refuge from the logging and urban development that goes on all around them.

While the banded surili is generally considered Near Threatened by the International Union for Conservation of Nature (IUCN), the Singapore population of Raffles’ banded langur is considered Critically Endangered nationally.

Though they have been governmentally protected there since 1947, their numbers have dwindled considerably since that time. Forty years ago, only 10-15 individuals existed. Today, in the wake of a more regimented conservation project, their population has risen to somewhere between 40 and 60 individuals. They are confined to the Nee Soon Swamp Forest in Central Catchmet Nature Reserve (CCNR), which is the country’s largest nature reserve at the heart of the island.

Raffles’ banded langur was once common throughout Singapore, however. Unfortunately, the population that once inhabited the Bukit Timah Nature Reserve (BTNR), a smaller reserve just west of CCNR, was wiped out by 1987. 

The two reserves had been connected to one another prior to the construction of the Bukit Timah Expressway, completed in 1983. Its construction is considered a major factor in the decimation of the BTNR population.

The Raffles' banded langur (Presbytis femoralis), also known as the banded leaf monkey or banded surili, is a species of primate in the family Cercopithecidae. It is endemic to Singapore and southern Peninsular Malaysia.

The banded surili is diurnal and arboreal, preferring rainforest with trees of the family Dipterocarpaceae.

​The species underwent taxonomic revisions in 2019 and 2020, in which two former subspecies were elevated to separate species. As a result, the Raffles' banded langur meets the criteria for being listed as vulnerable by the IUCN. It is mainly threatened by habitat loss.

The taxonomy of Presbytis femoralis underwent several changes. Up until 2019, three subspecies of 

P. femoralis were recognized: P. f. femoralis (nominate), P. f. percura (the East Sumatran banded langur), 

and P. f. robinsoni (Robinson's banded langur).

Presbytis f. femoralis lives in Singapore, and in the states of Johor and Pahang of southern Peninsular Malaysia, P. f. robinsoni lives in the northern Malay Peninsula, including southern Myanmar and Thailand, and P. f. percura lives in east-central Sumatra.

Genetic data suggested that at least P. f. femoralis and P. f. robinsoni were different species which was also in agreement with their morphological characters. However, resolving all subspecies-level boundaries within banded langurs required data for P. f. percura, which was the least studied among them.

Most recently, mitochondrial genomes were obtained for P. f. percura, and based on multiple species delimitation algorithms (PTP, ABGD, Objective Clustering) applied to a dataset covering 40 species and 43 subspecies of Asian colobines, all three subspecies of banded langurs were resurrected to species.

William Charles Linnaeus Martin formally described P. femoralis based on material that had been collected by Sir Stamford Raffles in Singapore. Martin had given the distribution as "Sumatra etc.", not mentioning Singapore explicitly, resulting in some confusion over the actual type locality. Gerrit Smith Miller resolved the issue in 1934, determining that Singapore was the actual type locality.

The Raffles' banded langur is 43.2 to 61.0 centimetres (17.0 to 24.0 in) long, excluding the tail, with a tail length of 61.0 to 83.8 centimetres (24.0 to 33.0 in). It weighs 5.9 to 8.2 kilograms (13 to 18 lb). It has dark fur on the back and sides with white-colored fur forming a band on the chest and along the inner thighs.

The Raffles' banded langur is diurnal and arboreal, preferring rainforest with trees of the family

Dipterocarpaceae. It comes to the ground less frequently than most other leaf monkeys. It lives in both primary and secondary forest, and also in swamp forests and mangrove forests, and even in rubber plantations. It moves primarily by walking on all fours and by leaping.

According to wildlife researcher Charles Francis, it typically lives in groups of 3 to 6. However, a study in Perawang, Sumatra found an average group size of 11 monkeys in mixed-sex groups.

The latter study also found an average ratio of 1 adult male to 4.8 adult females in mixed-sex groups and a ratio of 1.25 adult monkeys for every immature monkey in mixed-sex groups. It also found an average range size for a group of 22 hectares, and an average population density of 42 monkeys per square kilometer. Other studies found somewhat smaller home ranges, of between 9 and 21 hectares.

The Raffles' banded langur appears to have two birth seasons, once between June and July and another between December and January. In this study, at least six infants were born between 2008 and 2010, and the authors found low infant mortality, with several infants surviving at least to seven months old. The study also found that the infant coloration of the Singapore population is indistinguishable from that of the Johor.

Malaysia population, with infants having white fur with a black stripe down the back from the head to the tail, crossed by another black stripe across the shoulders and to the forearms. Males leave their natal group before reaching maturity, at about 4 years old.

The call of mature males sounds like "ke-ke-ke." Mammalogist Ronald M. Nowak described the species' alarm call as "a harsh rattle followed by a loud chak-chak-chak-chak."

The Raffles' banded langur has a primarily vegetarian diet. Specialized bacteria in its gut allow it to digest leaves and unripe fruit. The Perawang study found that nearly 60% of the diet consisted of fruits and seeds. Another 30% consisted of leaves, primarily young leaves. A different study found that fruit made up 49% of the diet. Unlike some other monkeys, such as the long-tailed macaque, the banded langur destroys the seeds it eats, and so it is not a significant factor in dispersing seeds.

The IUCN assessed Presbytis femoralis as being vulnerable in 2020. At the time they assessed the (then) subspecies P. f. femoralis as vulnerable. After the taxonomic reassessment, there are only about 300–400 Raffles' banded langurs remaining—about 250 to 300 and possibly fewer in Malaysia and about 60 in Singapore.

As a result of the small, fragmented population and continuing risk of further deforestation, the species meets the criteria to be listed as vulnerable by IUCN.

The Raffles' banded langur was once common throughout the island of Singapore but that population is now critically endangered with approximately 60 individuals left in the Central Catchment Nature Reserve.

The species was formerly found in the Bukit Timah Nature Reserve, but that population died out in 1987. The last individual to live in Bukit Timah is now displayed at the Raffles Museum of Biodiversity Research. 

The Central Catchment population had declined to as few as 10–15 monkeys before recovering to about 40 by 2012 and 60 by 2019. The Singapore population feeds from at least 27 plant species, including Hevea brasiliensis leaves, Adinandra dumosa flowers and Nephelium lappaceum fruits. They appear to prefer specific fruits and will travel long distances to reach their preferred fruit, rather than settle for more accessible foods.

The National Biodiversity Centre, in partnership with the Evolution Lab of the National University of Singapore, launched an ecological study to determine suitable conservation strategies. In 2012 study found extremely low genetic diversity within the remaining Singapore population and suggested that translocation of Raffles' banded langurs from Malaysia may be necessary to provide the Singapore population with enough genetic diversity to survive in the long run.

In 2016, a cross-border partnership between Singapore and Malaysia was formed with the establishment of a Raffles' Banded Langur Working Group funded by the Wildlife Reserves Singapore Conservation Fund. The main threat to the Singapore population appears to be habitat loss. 99.8% of Singapore's original primary forest, including much of its dipterocarp flora, has been eliminated, with less than 200 ha remaining, primarily in Bukit Timah and the MacRitchie Reservoir and Nee Soon Swamp Forest portions of Central Catchment.

The Nee Soon Swamp Forest is the primary area of Central Catchment where the Raffles' banded langur is found. The monkey groups inhabit forest fragments that have limited arboreal connections to other fragments. Other contributors to the species' decline in Singapore have been hunting for food and the pet trade. The species has been legally protected in Singapore since 1947.

​The Singapore government hopes that the development of Thomson Nature Park near Central Catchment will help maintain the Raffles' banded langur population, since it is located near a traditional feeding area for the monkeys and will increase the forested area they can use. They also hope that eventually when the vegetation matures the Eco-Link@BKE will allow banded leaf monkeys to repopulate Bukit Timah.

A group of bachelor males once tried to make its way to Bukit Timah without using the EcoLink but one was killed crossing the highway and the group now lives in Windsor Nature Park. In April 2021 a single Raffles' banded langur was observed in Bukit Timah but it is unclear whether it used the Eco-Link@BKE to get there.

The National Parks Board staff wrote of the sighting at the website of the Lee Kong Chian Natural History Museum. Concerns have been raised as to whether construction of the Cross Island MRT line through Central Catchment may adversely impact the Raffles' banded langur population in the area.

In 2020 a group of two dusky leaf monkeys was observed in Singapore, possibly having swum from Johor, and they were able to chase away a group of eleven Raffles' banded langurs that had been feeding on Adenanthera pavonina seeds.

Phylum : Chordata

Class:  Mammalia

Order : Primates

Suborder : Haplorhini

Infraorder : Simiiformes

Family : Cercopithecidae

​Subfamily : Colobinae

Genus : Presbytis Eschscholtz, 1821

Species : P. femoralis

Binomial name : Presbytis femoralis

(Martin, 1838)

The crab-eating macaque (Macaca fascicularis), also known as the long-tailed macaque, is a cercopithecine primate native to Southeast Asia.

It is referred to as the cynomolgus monkey in laboratories. It has a long history alongside humans; they have been alternately seen as agricultural pests, sacred animals in some temples, and more recently, the subject of medical experiments.

The crab-eating macaque lives in matrilineal social groups with a female dominance hierarchy, and male members leave the group when they reach puberty.

They are opportunistic omnivores and have been documented using tools to obtain food in Thailand and Myanmar. The significant overlap in macaque and human living space has resulted in greater habitat loss, synanthropic living, and inter- and intraspecies conflicts over resources.

The body length of the adult, which varies among subspecies, is 38–55 cm (15–22 in) with relatively short arms and legs. Males are considerably larger than females, weighing 5–9 kg (11–20 lb) compared to the 3–6 kg (6.6–13.2 lb) of females.

The tail is longer than the body, typically 40–65 cm (16–26 in), which is used for balance when they jump distances up to 5 m (16 ft). The upper parts of the body are dark brown with light golden brown tips. The under parts are light grey with a dark grey/brown tail.

Crab-eating macaques have backwards-directed crown hairs which sometimes form short crests on the midline. Their skin is black on their feet and ears, whereas the skin on the muzzle is a light grayish pink color. The eyelids often have prominent white markings and sometimes there are white spots on the ears.

Males have a characteristic mustache and cheek whiskers, while females have only cheek whiskers. Crab-eating macaques have a cheek pouch which they use to store food while foraging. Females show no perineal swelling.

The crab-eating macaque is a known invasive species and a threat to biodiversity in several locations, including Hong Kong and western New Guinea. 

Phylum : Chordata

Class : Mammalia

Order : Primates

Suborder : Haplorhini

Infraorder : Simiiformes

Family : Cercopithecidae

Genus : Macaca

Species : M. fascicularis

Binomial Name : Macaca fascicularis