Discover Life - Loridae: Nycticebus pygmaeus Bonhote, 1907

2010/02/07 04:04:34.681 US/Eastern

By Nita Bharti

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Mammalia

Order: Primates

Suborder: Strepsirrhini

Family: Lorisidae

Genus: Nycticebus

Species: Nycticebus pygmaeus

Geographic Range

Nycticebus pygmaeus is found in the secondary forests of many different countries including Vietnam, Laos, China, Thailand, and parts of Cambodia. This species is closely related to Nycticebus coucang and they share this geographic range.

Some scientists consider N. pygmaeus , the lesser or pygmy slow loris, to be similar enough to N. coucang , the slow loris, to be considered a subspecies. However, most taxonomic classifications group them separately as distinct species.

Biogeographic Regions:
oriental ( native ).

Habitat

Pygmy slow lorises are found in the thickest vegetation of tropical rainforests. They are also found in bamboo groves.

Terrestrial Biomes:
rainforest .

Physical Description

Mass
1 kg (average)
(2.2 lbs)

N. pygmaeus is about the size of a large chipmunk. It is 6-10 inches (15-25 cm) long including its head and body. This animal weighs approximately 1 kg (2 lbs).

The wooly coat of the pygmy slow loris is short and thick. The coloration ranges from light brownish gray to deep reddish brown. The individual hairs can have lighter tips. Often, a dark midline can be found along the neck and back. It is also possible for a light streak between the dark orbital rings to be present.

These lorises have large forward oriented eyes with binocular vision. Their head and eyes are rounded. Their ears are small and are nearly hidden by their thick fur.

These pygmy slow lorises do not have tails but are well equipped for climbing trees because of their opposable thumbs. The pollex is perpendicular to the other fingers. The hallux points slightly backwards relative to other hindfoot digits. Each of the digits has a nail with the exception of the hindfoot's second digit which has a claw.

N. pygmaeus has a strong grip due to the muscles in its hands and feet. This allows for an effortless yet rigid grasp with both the forefeet and hindfeet. There exist storage channels for blood in this animal's hands and feet. This enables a clenched position to remain without tiring for long periods of time.

Some key physical features:
endothermic ; bilateral symmetry .

Reproduction

Breeding interval
Pygmy slow lorises mate only once every 12-18 months.

Number of offspring
1 to 2

Gestation period
188 days (average)

Birth Mass
23 g (average)
(0.81 oz)
[ External Source: AnAge ]

Time to weaning
133 days (average)

Age at sexual or reproductive maturity (female)
9 months (average)

Age at sexual or reproductive maturity (male)
17 to 20 months

The N. pygmaeus mating system involves one male and multiple females. These animals are socially solitary so there is no tight group living in this polygynous system. A male's range may overlap the home ranges of two or three females. Males check urine scent marks for signs of estrus in the females.

Mating systems:
polygynous .

Each sex contacts the other by whistles. Females reach sexual maturity at around nine months of age while males do the same around the age of 17-20 months.

Pygmy slow lorises mate only once every 12-18 months and have one or two offspring every 12-18 months. Females have a 37-54 day estrus cycle. They are receptive for 5-6 days. The gestation period for this species is around 188 days. Births usually occur in the open instead of in a nest.

Key reproductive features:
iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .

When initially born, a young loris clings to its mother's belly. Soon after, it will drop to a branch or nest where it will remain hidden in the thick vegetation while its mother forages. Later, the offspring will follow its mother when she goes out foraging and will learn what food to seek by observing her.

Newborn infants resemble miniature adults. This is because they are so well developed at birth. Their eyes open on the day they are born and they possess a full fur coat. This is the reason they can be left unattended on branches. They are nursed for up to nine months.

Mothers and infants maintain contact through vocal communication. Mothers use soft chirps and infants emit a series of rapid clicks and squeaks as distress signals. When mothers hear this distress call, they return to their child immediately.

Parental investment:
pre-fertilization (protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (provisioning: female, protecting: female); extended period of juvenile learning.

Behavior

Nycticebus pygmaeus is a nocturnal, arboreal species. Individuals are fairly solitary, living in loose groups that seem to include many females but only one male. The adult males are highly territorial and mark their area with their urine.

These lorises are slow moving animals that forage alone and do so at night. They are active all night and pause only to feed. Their slow movement has been described as chameleon-like because it makes them difficult to detect amidst the thick vegetation of their habitat. They have lost the well developed ability of leaping that lemurs and galagos retain. They travel along branches walking hand over foot.

While they are known as generally slow moving, they are capable of moving at a faster pace than they generally exhibit and can strike with great speed. N. pygmaeus will grip a branch with both feet while standing erect and throw its body forward in order to seize prey with both hands. They locate their prey primarily by using their sense of smell and their large eyes with binocular vision.

These strongly arboreal lorises seldom drop from the trees. They will do so when they are frightened, occasionally while escaping a predator.

They communicate vocally for many reasons. Courtship calls are used as signals between sexes and mothers and infants communicate in this manner. A low buzzing growl or a hiss can indicate an animal has been disturbed, a high pitch "twitter" is made when annoyed, and a high whistle is emitted by a female in estrus.

Communication is also achieved through olfactory means by N. pygmaeus . Pygmy lorises emanate a substance with a strong odor that, when combined with saliva, can be toxic. The scent warns predators of a foul taste should they attempt to bite the loris. This substance is produced by a gland on the forearm's inner surface. This secretion can be so toxic that only a small amount is capable of sending a human into shock.

Lorises can freeze motionless for long periods of time. Their often comical postures are responsible for their name -- "loris" is derived from the Dutch word for "clown".

Pygmy lorises will sometimes hang from branches with their feet so they can use both their hands to eat. They sleep rolled up in a tight ball with their head between their legs.

Key behaviors:
arboreal ; nocturnal ; motile ; solitary ; territorial .

Food Habits

N. pygmaeus is a nocturnal forager. In the wild, its diet is known to consist of large mollusks, insects (caterpillars, beetles, and millipedes) , eggs, lizards, birds, small mammals, fruits, and other vegetation. The insects this primate consumes are often foul smelling and can be located by the loris' sense of smell.

In captivity this loris is fed apples, grapes, TBS primate diet, Monkey chow, oranges, greens, and the components of a leaf eater's diet and a variety of other foods by zoos.

Primary Diet:
omnivore .

Animal Foods:
birds; mammals; reptiles; eggs; insects; mollusks.

Plant Foods:
fruit.

Economic Importance for Humans: Positive

Pygymy slow lorises are valuable to humans for medicinal purposes. The species holds therapeutic value for those who believe it has healing capabilities.

These small primates are also captured as pets. In these ways, these lorises are beneficial to humans.

Conservation Status

IUCN Red List: [link] :
Vulnerable.

US Federal List: [link] :
Threatened .

CITES: [link] :
Appendix II.

Nycticebus pygmaeus is not hunted by man (although some are collected for captivity), probably because of its small size. It is threatened most by habitat destruction. Environmental disruption by deforestation and military activity are its greatest hazards due its restricted habitat.

Technically listed as threatened, this species was first given this status in 1976. The Vietnam War nearly wiped out this species of loris. Recently, however, wild populations of N. pygmaeus have seen significant growth.

This animal is also coveted for capture for its use as a pet and for medicinal trade, although this is not responsible for its low numbers. Of the remaining wild populations, only 13% are found in protected areas.

Some effort is being made to house and breed these animals in captivity. There are currently two pygmy slow lorises in the Duke Primate Center.

The Brookfield Zoo also houses Nycticebus pygmaeus as one of over 32 species with Species Survival Plans (SSPs). An SSP is a long term captive breeding program that intends to protect a species from extinction.

Other zoos around the world also hold captive pygmy slow lorises for conservation purposes.

For More Information

Find Nycticebus pygmaeus information at

Encyclopedia of Life

Contributors

Nita Bharti (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.

References

"What is a slender loris?" (On-line). Accessed November 21, 1999 at http://www.artsci.wustl.edu/~kabiela/whatis.html .

"Lesser Slow Loris" (On-line). Accessed November 21, 1999 at http://members.tripod.com/uakari/nycticebus_pygmaeus.html .

CLEVELAND METROPARKS ZOO EDUCATION DIVISION, "Conservation Species Survival Plan" (On-line). Accessed November 21, 1999 at http://clemetzoo.com/conservation.html .

CLEVELAND METROPARKS ZOO EDUCATION DIVISION, "Lesser Slow Loris" (On-line). Accessed November 21, 1999 at http://clemetzoo.com/animal_info/Loris%2C%20Lesser%20Slow.htm .

National Wildlife Federation, "Endangered Animals" (On-line). Accessed November 21, 1999 at http://members.tripod.com/billybobjoe85/endan.htm .

Primate Gallery, "LORIDAE: Pottos and Lorises" (On-line). Accessed November 21, 1999 at http://www.selu.com/~bio/PrimateGallery/primates/Loridae.html .

The Houston Zoo, "Lesser Slow Loris" (On-line). Accessed November 21, 1999 at http://www.houstonzoo.org/mammals/pages/lrslris.htm .

September 30, 1999. "U.S. FISH AND WILDLIFE SERVICE DIVISION OF ENDANGERED SPECIES" (On-line). Accessed November 21, 1999 at http://endangered.fws.gov/fmammal2.html#Lnk6j .

Chicago Zoological Society, 1997. "Brookfield Zoo's SSP Animals" (On-line). Accessed November 21, 1999 at http://www.brookfieldzoo.org/consres/ssplist.html .

Duke Primate Center, July 28, 1999. "Pygmy Slow Loris" (On-line). Accessed November 21, 1999 at http://www.duke.edu/web/primate/pygmylor.html .

2010/02/07 04:04:36.101 US/Eastern

To cite this page: Bharti, N. 2000. "Nycticebus pygmaeus" (On-line), Animal Diversity Web. Accessed February 09, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Nycticebus_pygmaeus.html.

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Nycticebus pygmaeus Bonhote, 1907

Nycticebus pygmaeus pygmy slow loris