Javan slow loris
Encyclopedia
The Javan slow loris is a strepsirrhine
primate
and a species of slow loris
native to the western and central portions of the island of Java
, in Indonesia
. Although originally described as a separate species, it was considered a subspecies
of the Sunda slow loris (N. coucang) for many years, until re-assessments of its morphology
and genetics in the 2000s resulted in its promotion to full species status. It is most closely related to the Sunda slow loris and the Bengal slow loris
(N. bengalensis). The species has two forms, based on hair length and, to a lesser extent, coloration.
Its forehead has a prominent white diamond pattern, which is formed by a distinct stripe that runs over its head and forks towards the eyes and ears. The Javan slow loris weighs between 565 and 687 g (1.2 and 1.5 lb) and has a head-body length of about 293 mm (11.5 in). Like all lorises it is arboreal
, and moves slowly across vines and liana
s instead of jumping from tree to tree. Its habitat includes primary and secondary forest
s, but it can also be found in bamboo forests, mangrove
forests, and on chocolate plantations. Its diet typically consists of fruit, tree gum
, lizards and eggs. It sleeps on exposed branches, sometimes in groups, and is usually seen alone or in pairs.
The Javan slow loris population is in sharp decline because of poaching
for the exotic pet
trade. It is also used in research associated with traditional medicine
. Remaining populations have low densities
, and habitat loss
is a major threat. For these reasons the International Union for Conservation of Nature (IUCN) lists its status as "endangered
", and it is also been included on the 2008–2010 list of "The World's 25 Most Endangered Primates
". It is protected by Indonesian law and, since June 2007, is listed under CITES Appendix I. Despite these protections, as well as its presence in several protected area
s, poaching continues; the wildlife protection laws are rarely enforced at the local level.
scientifically in 1812, by the French naturalist Étienne Geoffroy Saint-Hilaire
. The species name javanicus refers to its place of origin. However, the species was not recognized for long; by 1840, René Primevère Lesson classified it as one of several varieties of a single species of slow loris, which he called Bradylemur tardigradus. In 1921, Oldfield Thomas
named a second species of slow loris from Java, Nycticebus ornatus.
In his 1971 review of slow loris taxonomy, taxonomist and primatologist Colin Groves
recognized the Javan slow loris as a subspecies
, Nycticebus coucang javanicus, of the Sunda slow loris (N. coucang), with ornatus as a synonym
. It was first recognized as a distinct species again in a 2000 Indonesian field guide
on primates by Jatna Supriatna and Edy Hendras Wahyono. In 2008, Groves and Ibnu Maryanto promoted it to species status, based on an analysis of cranial morphology
and characteristics of pelage
. Molecular analysis of DNA sequence
s of the D-loop
and cytochrome b
genes demonstrated it to be genetically distinct from other slow loris species; phylogenetically
, it is sister to a clade
containing the Bengal slow loris
(N. bengalensis) and the Sunda slow loris. Due to its close resemblance to neighboring slow loris species, even rescue centers have been known to misidentify it.
There are two forms of the Javan slow loris, distinguished mainly by differences in hair length. These have occasionally been recognized as separate species, N. javanicus and N. ornatus, but are currently both classified as a single species, although their exact taxonomic status remains unclear.
(N. menagensis), it lacks the second incisor
(I2) in its dentition
.
The Javan slow loris is larger than both of the other Indonesian slow lorises, the Sunda slow loris and the Bornean slow loris. Based on averages determined from six specimens obtained from the illegal wildlife trade in Java, other morphometric
parameters are as follows: head length, 59.2 mm; muzzle
length, 19.9 mm; head breadth, 43.6 mm; body breadth, 250.8 mm; head and body length, 293.1 mm; chest girth, 190.8 mm; dark percentage girth (girth measurement of zone with dark dorsal hair, measured as a percent of girth circumference), 48.0 mm; neck circumference, 136.7 mm; tail length, 20.4 mm; humerus
length, 67.2 mm; radius
length, 71.8 mm; tibia
length, 85.9 mm; hand span, 59.1 mm; foot span, 70.3 mm; and ear length, 16.8 mm.
The ornatus morphotype is most reliably distinguished by its longer fur, averaging 26.8 mm compared to 22.4 mm in javanicus. Other distinguishing characteristics include overall color (generally light brown in ornatus compared with brown to reddish in javanicus), and amount of brown coloring in the fur (ornatus has less brown than javanicus, resulting in a lighter-colored ventral region).
In the 1860s, the brain
of the Javan slow loris was examined by William Henry Flower
, a comparative anatomist
who specialized in the primate brain. In addition to detailing the organization, shape, and measurements of its brain, he noted that the form and surface markings were comparable to that of lemur
s. He argued against grouping strepsirrhines with Insectivora
(a now-abandoned biological grouping) and noted that the brain had features transitional between other primates and "inferior" mammals such as bat
s and carnivora
ns.
es, the Javan slow loris is nocturnal and arboreal, relying on vines and liana
s. However, the animal has been observed moving on the ground to cross open spaces in disturbed habitat. It moves through the canopy at heights between 3 and 22 m (9.8 and 72.2 ft) and is often encountered at heights between 1.5 and 9.5 m (4.9 and 31.2 ft).
The Javan slow loris will eat fruit, lizards, eggs, and chocolate seeds. It is also known to eat the gum
of trees of the genus Albizia
, in the legume family, Fabaceae
, as well as from the palm genus Arenga
(family Arecaceae
). Javan slow lorises are seen alone or in pairs and are sometimes found sleeping in groups. Instead of sleeping in nest holes, they sleep curled up on branches. Like other slow lorises, the Javan slow loris has a distinctive call that resembles a high-frequency whistle. The species is a host for the parasitic flatworm
, Phaneropsolus oviforme.
. Its presence has been confirmed in the Dieng Mountains, and it is known to be found in low densities at Gunung Gede Pangrango National Park
(in montane
cloud forest
s) and Mount Halimun Salak National Park, often only where human disturbance is minimal. It inhabits both primary and secondary disturbed forest, and can be found from sea level to 1600 m (5,249.3 ft), although it is more commonly found at higher elevations since lower elevations tend to be deforested. A study in 2000 showed that in addition to primary and secondary forest, the Javan slow loris could be found in bamboo forests, mangrove
forests, and on plantations—particularly chocolate plantations. In 2008, they were observed in West Java to occupy mixed-crop home gardens, tolerating high levels of human disturbance.
," primarily due to a rapid decline in population. For the 21–24 years prior to its 2008 assessment by the IUCN—which corresponds to three generations for the species—its numbers had dropped by at least 50%. Population data for the species is sparse, but a few studies have shown a low population density
of 0.20 to 0.02 individuals per km2.
Its numbers are still decreasing, primarily because of poaching
. In Indonesia, it is sometimes used in traditional medicine
, because of myths of it having magical and curative properties, but it is more frequently sold as an exotic pet
. The species is easily captured because of its slow movement, nocturnal habits, and its tendency to sleep on exposed branches. They are both actively sought for the pet trade and collected opportunistically when felling forests. Its habitat is also in decline, although most of the habitat loss
occurred by the mid-1980s. Within its range, human land use is intense. Environmental niche modelling
indicates that the Javan slow loris is more threatened by habitat loss than other slow loris species. For these reasons, the Javan slow loris has been included on "The World's 25 Most Endangered Primates
" published by the IUCN Species Survival Commission Primate Specialist Group (IUCN/SSC PSG), the International Primatological Society
(IPS), and Conservation International
(CI).
Along with all other slow lorises, the Javan slow loris was elevated from CITES Appendix II to CITES Appendix I in June 2007, offering it increased protection from commercial trade. It is also protected by Indonesian law, but according to loris researchers Nekaris and Jaffe, "effective law enforcement with respect to wildlife protection laws is all but non-existent in Indonesia". The species can be found in several protected area
s, but its numbers are uncertain. Captive collections of the Javan slow loris can be found in Prague
, Czech Republic, Jakarta
, Indonesia, and Singapore
.
Strepsirrhini
The clade Strepsirrhini is one of the two suborders of primates. Madagascar's only non-human primates are strepsirrhines, and others can be found in southeast Asia and Africa...
primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
and a species of slow loris
Slow loris
Slow lorises are a group of five species of strepsirrhine primates which make up the genus Nycticebus. Found in South and Southeast Asia, they range from Northeast India in the west to the Philippines in the east, and from the Yunnan province in China in the north to the island of Java in the south...
native to the western and central portions of the island of Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
, in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. Although originally described as a separate species, it was considered a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Sunda slow loris (N. coucang) for many years, until re-assessments of its morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
and genetics in the 2000s resulted in its promotion to full species status. It is most closely related to the Sunda slow loris and the Bengal slow loris
Bengal Slow Loris
The Bengal slow loris or northern slow loris is a strepsirrhine primate and a species of slow loris native to the Indian subcontinent and Indochina. Its geographic range is larger than that of any other slow loris species...
(N. bengalensis). The species has two forms, based on hair length and, to a lesser extent, coloration.
Its forehead has a prominent white diamond pattern, which is formed by a distinct stripe that runs over its head and forks towards the eyes and ears. The Javan slow loris weighs between 565 and 687 g (1.2 and 1.5 lb) and has a head-body length of about 293 mm (11.5 in). Like all lorises it is arboreal
Arboreal locomotion
Arboreal locomotion is the locomotion of animals in trees. In every habitat in which trees are present, animals have evolved to move in them. Some animals may only scale trees occasionally, while others are exclusively arboreal. These habitats pose numerous mechanical challenges to animals...
, and moves slowly across vines and liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s instead of jumping from tree to tree. Its habitat includes primary and secondary forest
Secondary forest
A secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
s, but it can also be found in bamboo forests, mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
forests, and on chocolate plantations. Its diet typically consists of fruit, tree gum
Natural gum
Natural gums are polysaccharides of natural origin, capable of causing a large viscosity increase in solution, even at small concentrations. In the food industry they are used as thickening agents, gelling agents, emulsifying agents, and stabilizers...
, lizards and eggs. It sleeps on exposed branches, sometimes in groups, and is usually seen alone or in pairs.
The Javan slow loris population is in sharp decline because of poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
for the exotic pet
Exotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
trade. It is also used in research associated with traditional medicine
Traditional medicine
Traditional medicine comprises unscientific knowledge systems that developed over generations within various societies before the era of modern medicine...
. Remaining populations have low densities
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
, and habitat loss
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
is a major threat. For these reasons the International Union for Conservation of Nature (IUCN) lists its status as "endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
", and it is also been included on the 2008–2010 list of "The World's 25 Most Endangered Primates
The World's 25 Most Endangered Primates
The World's 25 Most Endangered Primates is a list of highly endangered primate species selected and published by the International Union for Conservation of Nature Species Survival Commission Primate Specialist Group , the International Primatological Society , and Conservation International...
". It is protected by Indonesian law and, since June 2007, is listed under CITES Appendix I. Despite these protections, as well as its presence in several protected area
Protected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
s, poaching continues; the wildlife protection laws are rarely enforced at the local level.
Taxonomy and phylogeny
The Javan slow loris (Nycticebus javanicus) was first describedSpecies description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
scientifically in 1812, by the French naturalist Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire was a French naturalist who established the principle of "unity of composition". He was a colleague of Jean-Baptiste Lamarck and expanded and defended Lamarck's evolutionary theories...
. The species name javanicus refers to its place of origin. However, the species was not recognized for long; by 1840, René Primevère Lesson classified it as one of several varieties of a single species of slow loris, which he called Bradylemur tardigradus. In 1921, Oldfield Thomas
Oldfield Thomas
Oldfield Thomas FRS was a British zoologist.Thomas worked at the Natural History Museum on mammals, describing about 2,000 new species and sub-species for the first time. He was appointed to the Museum Secretary's office in 1876, transferring to the Zoological Department in 1878...
named a second species of slow loris from Java, Nycticebus ornatus.
In his 1971 review of slow loris taxonomy, taxonomist and primatologist Colin Groves
Colin Groves
Colin Peter Groves is Professor of Biological Anthropology at the Australian National University in Canberra, Australia.Born in England on 24 June 1942, Colin Groves completed a Bachelor of Science at University College London in 1963, and a Doctor of Philosophy at the Royal Free Hospital School of...
recognized the Javan slow loris as a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, Nycticebus coucang javanicus, of the Sunda slow loris (N. coucang), with ornatus as a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
. It was first recognized as a distinct species again in a 2000 Indonesian field guide
Field guide
A field guide is a book designed to help the reader identify wildlife or other objects of natural occurrence . It is generally designed to be brought into the 'field' or local area where such objects exist to help distinguish between similar objects...
on primates by Jatna Supriatna and Edy Hendras Wahyono. In 2008, Groves and Ibnu Maryanto promoted it to species status, based on an analysis of cranial morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
and characteristics of pelage
Fur
Fur is a synonym for hair, used more in reference to non-human animals, usually mammals; particularly those with extensives body hair coverage. The term is sometimes used to refer to the body hair of an animal as a complete coat, also known as the "pelage". Fur is also used to refer to animal...
. Molecular analysis of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
s of the D-loop
D-loop
In molecular biology, a displacement loop or D-loop is a DNA structure where the two strands of a double-stranded DNA molecule are separated for a stretch and held apart by a third strand of DNA. The third strand has a base sequence which is complementary to one of the main strands and pairs with...
and cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
genes demonstrated it to be genetically distinct from other slow loris species; phylogenetically
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...
, it is sister to a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
containing the Bengal slow loris
Bengal Slow Loris
The Bengal slow loris or northern slow loris is a strepsirrhine primate and a species of slow loris native to the Indian subcontinent and Indochina. Its geographic range is larger than that of any other slow loris species...
(N. bengalensis) and the Sunda slow loris. Due to its close resemblance to neighboring slow loris species, even rescue centers have been known to misidentify it.
There are two forms of the Javan slow loris, distinguished mainly by differences in hair length. These have occasionally been recognized as separate species, N. javanicus and N. ornatus, but are currently both classified as a single species, although their exact taxonomic status remains unclear.
Anatomy and physiology
The Javan slow loris weighs between 565 and 687 g (1.2 and 1.5 lb) and is similar in appearance to the largest slow loris, the Bengal slow loris. Its face and back are marked with a distinct stripe that runs over the crown and forks, leading to the eyes and ears, which leaves a white diamond pattern on the forehead. Its color is yellowish-gray. In contrast, its head, neck, and shoulders have cream hues. Like the Bornean slow lorisBornean Slow Loris
The Bornean slow loris or Philippine slow loris is a strepsirrhine primate and a species of slow loris that is native to the island of Borneo , the nearby islands of Belitung and Bangka in Indonesia, and the Sulu Archipelago in the Philippines...
(N. menagensis), it lacks the second incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
(I2) in its dentition
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
.
The Javan slow loris is larger than both of the other Indonesian slow lorises, the Sunda slow loris and the Bornean slow loris. Based on averages determined from six specimens obtained from the illegal wildlife trade in Java, other morphometric
Morphometrics
Morphometrics refers to the quantitative analysis of form, a concept that encompasses size and shape. Morphometric analyses are commonly performed on organisms, and are useful in analyzing their fossil record, the impact of mutations on shape, developmental changes in form, covariances between...
parameters are as follows: head length, 59.2 mm; muzzle
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
length, 19.9 mm; head breadth, 43.6 mm; body breadth, 250.8 mm; head and body length, 293.1 mm; chest girth, 190.8 mm; dark percentage girth (girth measurement of zone with dark dorsal hair, measured as a percent of girth circumference), 48.0 mm; neck circumference, 136.7 mm; tail length, 20.4 mm; humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
length, 67.2 mm; radius
Radius (bone)
The radius is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna, which exceeds it in length and size. It is a long bone, prism-shaped and slightly curved longitudinally...
length, 71.8 mm; tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
length, 85.9 mm; hand span, 59.1 mm; foot span, 70.3 mm; and ear length, 16.8 mm.
The ornatus morphotype is most reliably distinguished by its longer fur, averaging 26.8 mm compared to 22.4 mm in javanicus. Other distinguishing characteristics include overall color (generally light brown in ornatus compared with brown to reddish in javanicus), and amount of brown coloring in the fur (ornatus has less brown than javanicus, resulting in a lighter-colored ventral region).
In the 1860s, the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
of the Javan slow loris was examined by William Henry Flower
William Henry Flower
Sir William Henry Flower KCB FRCS FRS was an English comparative anatomist and surgeon. Flower became a leading authority on mammals, and especially on the primate brain...
, a comparative anatomist
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
who specialized in the primate brain. In addition to detailing the organization, shape, and measurements of its brain, he noted that the form and surface markings were comparable to that of lemur
Lemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s. He argued against grouping strepsirrhines with Insectivora
Insectivora
The order Insectivora is a now-abandoned biological grouping within the class of mammals...
(a now-abandoned biological grouping) and noted that the brain had features transitional between other primates and "inferior" mammals such as bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s and carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...
ns.
Behavior and ecology
Like other lorisLoris
Loris is the common name for the strepsirrhine primates of the subfamily Lorisinae in family Lorisidae. Loris is one genus in this subfamily and includes the slender lorises, while Nycticebus is the genus for the slow lorises....
es, the Javan slow loris is nocturnal and arboreal, relying on vines and liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s. However, the animal has been observed moving on the ground to cross open spaces in disturbed habitat. It moves through the canopy at heights between 3 and 22 m (9.8 and 72.2 ft) and is often encountered at heights between 1.5 and 9.5 m (4.9 and 31.2 ft).
The Javan slow loris will eat fruit, lizards, eggs, and chocolate seeds. It is also known to eat the gum
Natural gum
Natural gums are polysaccharides of natural origin, capable of causing a large viscosity increase in solution, even at small concentrations. In the food industry they are used as thickening agents, gelling agents, emulsifying agents, and stabilizers...
of trees of the genus Albizia
Albizia
Albizia is a genus of about 150 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the legume family, Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, Central, South, and southern North America and Australia, but mostly...
, in the legume family, Fabaceae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
, as well as from the palm genus Arenga
Arenga
Arenga is a genus of 24 species of palms, native to tropical regions of southern and southeastern Asia. They are small to medium-sized palms, growing to 2-20 m tall, with pinnate leaves 2-12 m long.Species*Arenga australasica*Arenga brevipes...
(family Arecaceae
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
). Javan slow lorises are seen alone or in pairs and are sometimes found sleeping in groups. Instead of sleeping in nest holes, they sleep curled up on branches. Like other slow lorises, the Javan slow loris has a distinctive call that resembles a high-frequency whistle. The species is a host for the parasitic flatworm
Flatworm
The flatworms, known in scientific literature as Platyhelminthes or Plathelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals...
, Phaneropsolus oviforme.
Distribution
The species is found only on the western and central portion of the island of Java in IndonesiaIndonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. Its presence has been confirmed in the Dieng Mountains, and it is known to be found in low densities at Gunung Gede Pangrango National Park
Gunung Gede Pangrango National Park
Mount Gede Pangrango National Park is a national park in West Java, Indonesia. The park is centred on two volcanoes—Mount Gede and Mount Pangrango— and is 150 km² in area....
(in montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
cloud forest
Cloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
s) and Mount Halimun Salak National Park, often only where human disturbance is minimal. It inhabits both primary and secondary disturbed forest, and can be found from sea level to 1600 m (5,249.3 ft), although it is more commonly found at higher elevations since lower elevations tend to be deforested. A study in 2000 showed that in addition to primary and secondary forest, the Javan slow loris could be found in bamboo forests, mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
forests, and on plantations—particularly chocolate plantations. In 2008, they were observed in West Java to occupy mixed-crop home gardens, tolerating high levels of human disturbance.
Conservation
The Javan slow loris is listed by the International Union for Conservation of Nature (IUCN) as "endangeredEndangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
," primarily due to a rapid decline in population. For the 21–24 years prior to its 2008 assessment by the IUCN—which corresponds to three generations for the species—its numbers had dropped by at least 50%. Population data for the species is sparse, but a few studies have shown a low population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
of 0.20 to 0.02 individuals per km2.
Its numbers are still decreasing, primarily because of poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
. In Indonesia, it is sometimes used in traditional medicine
Traditional medicine
Traditional medicine comprises unscientific knowledge systems that developed over generations within various societies before the era of modern medicine...
, because of myths of it having magical and curative properties, but it is more frequently sold as an exotic pet
Exotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
. The species is easily captured because of its slow movement, nocturnal habits, and its tendency to sleep on exposed branches. They are both actively sought for the pet trade and collected opportunistically when felling forests. Its habitat is also in decline, although most of the habitat loss
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
occurred by the mid-1980s. Within its range, human land use is intense. Environmental niche modelling
Environmental niche modelling
Environmental niche modelling, alternatively known as species distribution modelling, niche modelling, and climate envelope modelling refers to the process of using computer algorithms to predict the distribution of species in geographic space on the basis of a mathematical representation of their...
indicates that the Javan slow loris is more threatened by habitat loss than other slow loris species. For these reasons, the Javan slow loris has been included on "The World's 25 Most Endangered Primates
The World's 25 Most Endangered Primates
The World's 25 Most Endangered Primates is a list of highly endangered primate species selected and published by the International Union for Conservation of Nature Species Survival Commission Primate Specialist Group , the International Primatological Society , and Conservation International...
" published by the IUCN Species Survival Commission Primate Specialist Group (IUCN/SSC PSG), the International Primatological Society
International Primatological Society
International Primatological Society is a scientific, educational, and charitable organization focused on non-human primates. It encourages scientific research in all areas of study, facilitates international cooperation among researchers, and promote primate conservation.Together with the IUCN...
(IPS), and Conservation International
Conservation International
Conservation International is a nonprofit organization headquartered in Arlington, Virginia, which seeks to ensure the health of humanity by protecting Earth's ecosystems and biodiversity. CI’s work focuses on six key initiatives that affect human well-being: climate, food security, freshwater...
(CI).
Along with all other slow lorises, the Javan slow loris was elevated from CITES Appendix II to CITES Appendix I in June 2007, offering it increased protection from commercial trade. It is also protected by Indonesian law, but according to loris researchers Nekaris and Jaffe, "effective law enforcement with respect to wildlife protection laws is all but non-existent in Indonesia". The species can be found in several protected area
Protected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
s, but its numbers are uncertain. Captive collections of the Javan slow loris can be found in Prague
Prague
Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...
, Czech Republic, Jakarta
Jakarta
Jakarta is the capital and largest city of Indonesia. Officially known as the Special Capital Territory of Jakarta, it is located on the northwest coast of Java, has an area of , and a population of 9,580,000. Jakarta is the country's economic, cultural and political centre...
, Indonesia, and Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
.