Geographic Range
Sunda slow lorises (
Nycticebus coucang
) live mainly in Indonesia (Sumatra, Batam and Galang in the Riau Archipelago, and
Pulau Tebingtinggi and Bunguran in the North Natuna Islands), Malaysia (on the Peninsula
and the island of Pulau Tioman), the southern peninsular area of Thailand (from the
Isthmus of Kra southward) and throughout Singapore.
Habitat
Sunda slow lorises mainly inhabit primary and secondary tropical lowland forests.
They have also been found in each of the following habitats: tropical evergreen and
semi-evergreen forests, seasonal wet evergreen forests, dry evergreen forests, mixed
deciduous tropical forests, sub-tropical broadleaf hill forests, swamp forests, savannahs,
montane and submontane forests, shrub forests, peat swamps and hardwood forests, as
well as degraded habitats such as highly disturbed forests, secondary forests, disturbed
primary forests and logged forests.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- scrub forest
Physical Description
Sunda slow lorises range in length from 27 to 38 centimeters and weight from 599 to
685 grams. They have a mostly white stripe between their eyes, beginning near the
top of their forehead and descending to the end of their nose. They usually have light
brown pelage with a darker-colored stripe running down their back. Thick fur hides
their ears. Their highly-reduced (to a stump) vestigial tail is also hidden underneath
their fur. Their eyes are large due to their primarily nocturnal activity. Their second
digit is reduced; their hands act as powerful clamps for grasping. Male and female
Sunda slow lorises do not vary by color, size or weight, in general, there is little
to no sexual dimorphism displayed by this species. They have a toothcomb and six procumbent
teeth on their lower jaw, consisting of the lower incisors and the canine teeth. Lorises
use their toothcomb to scrape off gum when foraging, and rarely use their toothcomb
for grooming (a common practice among other primates with toothcombs). Like other
slow lorises, these animals have wet noses, round heads, small ears hidden in thick
fur, a flat face and large eyes.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- poisonous
- Sexual Dimorphism
- sexes alike
Reproduction
Males track females in estrus; however, females initiate the act of copulation. To
initiate, the female hangs from a branch within sight of the male, often vocalizing
to draw further attention. The male then holds the female and the branch, while simultaneously
copulating with her. Urine-marking may also be used by the female to solicit mating.
The male may create a mating plug following copulation.
Slow lorises have been observed in groups of up to six conspecifics including a female
in estrus and five males. This may suggest a promiscuous mating system, where females
mate with more than one male. No further evidence for polyandrous mating has been
recorded, but the possibility is likely given their mating structure.
Sunda slow lorises are polyestrous, having many periods of sexual receptivity during
a year. Their estrus cycle lasts 29 to 45 days, with most copulations occurring in
succession. Their gestation period averages 188 days, after which one offspring is
born, although twinning has been observed. Offspring are weaned between three and
six months of age. Sexual maturity is reached between 18 and 24 months of age in females,
and can be reached as early as 17 months in males, although males typically become
sexually mature around 20 months.
- Key Reproductive Features
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
Only females care for their young. Before and during weaning, females lick their young,
covering them in toxic oil, so the young may be protected while the female leaves
to forage. Females also provide an example from which the young will learn to move
through the trees.
- Parental Investment
- female parental care
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
provisioning
- female
-
protecting
- female
-
provisioning
Lifespan/Longevity
In the wild, this species average life span is 20 years, including one individual
that survived 22 years. Their average life span in captivity is 24 years, including
the longest-lived individual on record, which survived 25.8 years. In captivity, Sunda
slow lorises tend to be more stressed and aggressive, which may result in a shorter
life span of 12 to 14 years.
Behavior
Sunda slow lorises move slowly through trees on all four limbs, typically with three
limbs attached to support at any given time. Their locomotion is similar to crawling.
They move with little noise or change in speed. At times they may hang below a branch
by one or both feet for long periods. In captivity, movement includes quadrupedal
locomotion (24%), climbing (21%), suspension (including cantilevering) (29%), bridging
(23%) and other forms of locomotion (3%).
Sunda slow lorises are mainly solitary, spending only 8% of their active time near
other individuals. In cases of home range overlap spatial groups form, usually consisting
of one male, one female and 1 to 3 younger individuals. Interactions among spatial
groups are mainly positive: allogrooming, following, pant-growling and click-calling
are all observed. Despite this, only 3% of active time is spent within the spatial
group. This evidence may suggest a monogamous social system, though polyandrous activity
has been observed.
Home Range
Upon witnessing a conspecific inside their home range, or when entering the home range
of another individual, this species generally shows no visible reaction; home ranges
do not appear to be defended. Although Sunda slow lorises commonly stay within their
own home range, they show no hesitation in entering another individual's home range
or in having others enter their own home range. The individual's range serves as a
general ground for activity, with no actual attachment to the range except by habit.
Communication and Perception
Adults exhibit eight distinct calls of one of two types: contact calls (whistles,
short keckers) and aggressive or defensive calls (long keckers, grunts, snarls, screams).
During mating, females may whistle when in visual contact with a male, in order to
draw attention. No alarm calls are used for signaling predators, as crypsis is the
most common response for avoidance. Infants may exhibit squeaks or clicks when disturbed.
Young individuals especially, but also adults, use ultrasonic vocalization when exploring
new environments or during complex handling (locomotion).
Olfactory senses play a central role in species interaction, with uses ranging from
alerting others of identity, to physical state and even positioning of the individual.
Their elbows contain glands that exude oils, which are licked and spread by the individual
to communicate position and status. This species also uses perineal rubbing to deposit
urine combined with the oil, from a separate gland on their anus. When locating the
scent of another, the individual will usually rub its face on the surface where the
scent was found. The oil is poisonous, with enough power to kill an adult human if
not treated properly. Stressed individuals may grin, baring their teeth to present
aggression or fear, but they may also grin during play.
- Other Communication Modes
- scent marks
- Perception Channels
- visual
- tactile
- ultrasound
- chemical
Food Habits
Sunda slow lorises are dietary generalists, feeding on saps, gums, nectars, stems,
fruits and occasionally arthropods such as
spiders
and
insects
. They have also been observed consuming
snails
and bird eggs. Roughly one third of their diet is saps and gums, another third consists
of nectar and nectar-producing plants and approximately one fourth of their diet is
fruit. The remainder of their diet consists of random items, such as snails and eggs.
Despite a very slow metabolic rate, this species has a high-energy diet, most likely
due to the energy costs of detoxifying certain ingested plant compounds.
- Animal Foods
- eggs
- insects
- terrestrial non-insect arthropods
- mollusks
- Plant Foods
- wood, bark, or stems
- fruit
- nectar
- sap or other plant fluids
Predation
All slow loris species, including Sunda slow lorises, produce a toxin in glands on
the insides of their elbows. Using their toothcomb during grooming, the toxin is spread
across their fur. If threatened, lorises will roll into a ball, leaving nothing but
toxic fur exposed to the predator. Lorises may also roll into a ball and drop from
the trees if the predator is arboreal. They may also bite, though this is very rare
compared to their more passive defenses such as crypsis. Their predators include
reticulated pythons
,
changeable hawk-eagles
and
Bornean orangutans
.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Sunda slow lorises have no major effect on their immediate environment. As a consumer,
they affect populations of flowering plants (consuming nectar and fruits), birds (consuming
eggs) and other taxa (namely
insects
and
mollusks
). As prey, they serve as food for larger taxa, such as
reticulated pythons
and
Bornean orangutans
. Sunda slow lorises do not defend their home range or territory, allowing individuals
of the same species and other species to pass through uninhibited.
- None
- Bengal slow loris ( Nycticebus bengalensis )
- None
Economic Importance for Humans: Positive
Sunda slow lorises are sold as exotic pets throughout Southeast Asia and more recently
in the western world. Slow lorises are the most commonly traded of the protected primates
in Southeast Asia. This species is also used for traditional medicines. Their fur
is reported to heal wounds, their flesh is used to cure epilepsy, their eyes are used
in love potions and their meat is reported to cure asthma and stomach problems.
- Positive Impacts
- pet trade
- source of medicine or drug
Economic Importance for Humans: Negative
Sunda slow lorises pose no serious threats for humans. Their only possible negative
effects include poisoning, caused either by consuming lorises or from being bitten
by a loris (an extremely rare event). The species is also treated as a crop pest in
some areas, though it has no actual effect on crop production or quality.
- Negative Impacts
-
injures humans
- bites or stings
- poisonous
- crop pest
Conservation Status
This species is greatly threatened by the pet trade. To prevent injury for owners,
their teeth are often removed, which almost always (90% of the time) leads to infection
and painful death. Once their teeth have been removed it is also impossible to re-introduce
them into the wild. Because of extreme mortality rates, mainly due to infection, improper
nutrition and heightened stress, the trade is further inflated by the constant need
for replacements. Likewise, human developments continue to encroach on their habitats.
The species is also threatened by gathering for illegal traditional medicine. They
are also killed as a crop pest. In addition to poaching, severe habitat loss and degradation
over large areas of their range have caused large population declines, despite the
species being more adaptable to human habitats than most other primates in the region.
The resulting fragmentation has restricted species dispersal as they depend on continuous
canopy cover to move from tree to tree.
Other Comments
The etymology of their common name, Sunda slow loris, refers to the Sunda Islands,
a group of islands in the western part of the Malay archipelago where they are found.
Another common name for the species is the greater slow loris. The specific name,
coucang, derives from kukang, their common name in Indonesia. They are commonly known
as malu-malu, meaning "shy" in Indonesian, and also as bukang or Kalamasan. In the
vernacular they are sometimes called Kuskus because local people in Indonesia do not
distinguish between the slow loris and Cuscus, a group of Australasian possums. In
Malaysia, they are sometimes known as kongkang or kera duku; kera is Malay for monkey
while duku is the fruit-bearing tree
Lansium domesticum
. In Thailand, they are called ling lom, which translates as "wind monkey".
Additional Links
Contributors
Paul Peña (author), Yale University, Eric Sargis (editor), Yale University, Leila Siciliano Martina (editor), Texas State University.
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- poisonous
-
an animal which has a substance capable of killing, injuring, or impairing other animals through its chemical action (for example, the skin of poison dart frogs).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- female parental care
-
parental care is carried out by females
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- ultrasound
-
uses sound above the range of human hearing for either navigation or communication or both
- chemical
-
uses smells or other chemicals to communicate
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- drug
-
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
- poisonous
-
an animal which has a substance capable of killing, injuring, or impairing other animals through its chemical action (for example, the skin of poison dart frogs).
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- nectarivore
-
an animal that mainly eats nectar from flowers
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
References
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