Lorisidae

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Lorisids [1]
Temporal range: Early Miocene–Recent
Nycticebus pygmaeus 004.jpg
Pygmy slow loris
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Strepsirrhini
Superfamily: Lorisoidea
Family: Lorisidae
Gray, 1821
Type genus
Loris
Geoffroy, 1796
Genera

Arctocebus
Perodicticus
Loris
Nycticebus
Xanthonycticebus

Contents

Synonyms
  • Loridae
    Jenkins, 1987 [2]

Lorisidae (or sometimes Loridae) is a family of strepsirrhine primates. The lorisids are all slim arboreal animals and comprise the lorises, pottos and angwantibos. Lorisids live in tropical, central Africa as well as in south and southeast Asia.

Classification

There are five genera and sixteen species of lorisid. [1]

Description

Lorisids have a close, woolly fur, which is usually grey or brown, darker on the top side. The eyes are large and face forward. The ears are small and often partially hidden in the fur. The thumbs are opposable and the index finger is short. The second toe of the hind legs has a fine claw for grooming, typical for strepsirrhines. Their tails are short or are missing completely. They grow to a length of 17 to 40 cm and a weight of between 0.3 and 2 kg, depending on the species. Their dental formula is similar to that of lemurs: 2.1.3.32.1.3.3

Behavior and ecology

Lorisids are nocturnal and arboreal. Unlike the closely related galagos, lorisids never jump. Some have slow deliberate movements, whilst others can move with some speed across branches. It was previously thought that all lorisids moved slowly, but investigations using red light proved this to be wrong. Nonetheless, even the faster species freeze or move slowly if they hear or see any potential predator. This habit of remaining motionless whilst in danger is successful only because of the leafy environment of their jungle home, which helps to conceal their true position. [4] With their strong hands they clasp at the branches and cannot be removed without significant force. Most lorisids are solitary or live in small family groups.

Slow lorises from southeast Asia produce a secretion from their brachial gland (a scent gland on the upper arm, between the axilla and elbow), that is licked and mixed with their saliva to form a toxin which may be used for defense. The red slender loris (Loris tardigradus) from India also possesses brachial glands, but it is uncertain whether they also synthesize the toxin. The potto (Perodicticus potto) is thought to lack brachial glands, though it produces similar toxic excretions with its anal glands. [5]

Lorisids have a gestation period of four to six months and give birth to two young. These often clasp themselves to the belly of the mother or wait in nests, while the mother goes to search for food. After three to nine months - depending on the species - they are weaned and are fully mature within 10 to 18 months. The life expectancy of lorises can be to up to 20 years.

Lorisids consume insects, bird eggs and small vertebrates as well as fruits and gums. [6] [7] [8] [9]

Related Research Articles

<span class="mw-page-title-main">Loris</span> Subfamily of primates

Loris is the common name for the strepsirrhine mammals of the subfamily Lorinae in the family Lorisidae. Loris is one genus in this subfamily and includes the slender lorises, Nycticebus is the genus containing the slow lorises, and Xanthonycticebus is the genus name of the pygmy slow loris.

<span class="mw-page-title-main">Strepsirrhini</span> Suborder of primates

Strepsirrhini or Strepsirhini is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison.

<span class="mw-page-title-main">Angwantibo</span> Genus of primates

Angwantibos are two species of strepsirrhine primates classified in the genus Arctocebus of the family Lorisidae. They are also known as golden pottos because of their yellow or golden coloration.

<span class="mw-page-title-main">Potto</span> Arboreal primate of west-central Africa

The pottos are three species of strepsirrhine primate in the genus Perodicticus of the family Lorisidae. In some English-speaking parts of Africa, they are called "softly-softlys".

<span class="mw-page-title-main">Slow loris</span> Genus of primates from Southeast Asia

Slow lorises are a group of several species of nocturnal strepsirrhine primates that make up the genus Nycticebus. Found in Southeast Asia and bordering areas, they range from Bangladesh and Northeast India in the west to the Sulu Archipelago in the Philippines in the east, and from Yunnan province in China in the north to the island of Java in the south. Although many previous classifications recognized as few as a single all-inclusive species, there are now at least eight that are considered valid: the Sunda slow loris (N. coucang), Bengal slow loris (N. bengalensis), Javan slow loris (N. javanicus), Philippine slow loris (N. menagensis), Bangka slow loris (N. bancanus), Bornean slow loris (N. borneanus), Kayan River slow loris (N. kayan) and Sumatran slow loris. A ninth species, the pygmy slow loris (X. pygmaeus), was recently moved to the new genus Xanthonycticebus. After the pygmy slow loris, the group's closest relatives are the slender lorises of southern India and Sri Lanka. Their next closest relatives are the African lorisids, the pottos, false pottos, and angwantibos. They are less closely related to the remaining lorisoids, and more distantly to the lemurs of Madagascar. Their evolutionary history is uncertain since their fossil record is patchy and molecular clock studies have given inconsistent results.

<span class="mw-page-title-main">Sunda slow loris</span> Species of primate found in South East Asia

The Sunda slow loris or greater slow loris is a strepsirrhine primate and a species of slow loris native to Indonesia, West Malaysia, southern Thailand and Singapore. It measures 27 to 38 cm from head to tail and weighs between 599 and 685 g. Like other slow lorises, it has a wet nose (rhinarium), a round head, small ears hidden in thick fur, a flat face, large eyes and a vestigial tail.

<span class="mw-page-title-main">Lorisoidea</span> Superfamily of primates

Lorisoidea is a superfamily of nocturnal primates found throughout Africa and Asia. Members include the galagos and the lorisids. As strepsirrhines, lorisoids are related to the lemurs of Madagascar and are sometimes included in the infraorder Lemuriformes, although they are also sometimes placed in their own infraorder, LorisiformesGregory, 1915.

<span class="mw-page-title-main">Golden angwantibo</span> Species of primate

The golden angwantibo is a strepsirrhine primate of the family Lorisidae. It shares the genus Arctocebus with the Calabar angwantibo and together they are commonly called the golden pottos. The golden angwantibo is found in Cameroon, the Republic of Congo, Equatorial Guinea and Gabon. Its usual habitat is rain forest, but it has also been known to live on farmland.

The false potto is a lorisoid primate of uncertain taxonomic status found in Africa. Anthropologist Jeffrey H. Schwartz named it in 1996 as the only species of the genus Pseudopotto on the basis of two specimens that had previously been identified as a potto (Perodicticus). The precise provenances of the two specimens are uncertain, but at least one may have come from Cameroon. Schwartz thought the false potto could even represent a separate family, but other researchers have argued that the supposed distinguishing features of the animal do not actually distinguish it from the potto; specifically, the false potto shares several features with the West African potto.

<span class="mw-page-title-main">Pygmy slow loris</span> Species of primate

The pygmy slow loris is a species of slow loris found east of the Mekong River in Vietnam, Laos, eastern Cambodia, and China. It occurs in a variety of forest habitats, including tropical dry forests, semi-evergreen, and evergreen forests. It was originally classified within Nycticebus until it was transferred to the genus Xanthonycticebus in 2022. Two species are recognised, the northern pygmy loris X. intermedius from northern Vietnam, Laos and China and the southern pygmy loris X. pygmaeus from southern Vietnam, Laos and Cambodia. The animal is nocturnal and arboreal, crawling along branches using slow movements in search of prey. Unlike other primates, it does not leap. It lives together in small groups usually with one or two offspring. An adult can grow to around 19 to 23 cm long and has a very short tail. It weighs about 450 g (1.0 lb). Its diet consists of fruits, insects, small fauna, tree sap, and floral nectar. The animal has a toxic bite, which it gets by licking a toxic secretion from glands on the inside of its elbows. The teeth in its lower jaw form a comb-like structure called a toothcomb that is used for scraping resin from tree bark.

<span class="mw-page-title-main">Bengal slow loris</span> Species of primate

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. Considered a subspecies of the Sunda slow loris (N. coucang) until 2001, phylogenetic analysis suggests that the Bengal slow loris is most closely related to the Sunda slow loris. However, some individuals in both species have mitochondrial DNA sequences that resemble those of the other species, due to introgressive hybridization. It is the largest species of slow loris, measuring 26 to 38 cm from head to tail and weighing between 1 and 2.1 kg. Like other slow lorises, it has a wet nose (rhinarium), a round head, flat face, large eyes, small ears, a vestigial tail, and dense, woolly fur. The toxin it secretes from its brachial gland differs chemically from that of other slow loris species and may be used to communicate information about sex, age, health, and social status.

<span class="mw-page-title-main">Slender loris</span> Genus of primates

The slender lorises (Loris) are a genus of loris native to India and Sri Lanka. The genus comprises two species, the red slender loris found in Sri Lanka and the gray slender loris from Sri Lanka and India. Slender lorises spend most of their life in trees, traveling along the tops of branches with slow and precise movements. They are found in tropical rainforests, scrub forests, semi-deciduous forests, and swamps. The primates have lifespans of approximately 15 years and are nocturnal. Slender lorises generally feed on insects, reptiles, plant shoots, and fruit.

<span class="mw-page-title-main">Gray slender loris</span> Species of primate

The gray slender loris is a species of primate in the family Loridae. It is native to India and Sri Lanka and inhabits subtropical and tropical dry forests and subtropical or tropical moist lowland forests. It is threatened by habitat loss.

<span class="mw-page-title-main">Philippine slow loris</span> Species of primate

The Philippine slow loris is a strepsirrhine primate and a species of slow loris that is native to the north and east coastal areas of the island of Borneo, as well as the Sulu Archipelago in the Philippines. The species was first named as the Bornean slow loris in 1892, but lumped into the widespread Sunda slow loris (N. coucang) in 1952. However, it was promoted to full species status – again as the Bornean slow loris – based on molecular analysis in 2006. In 2013, two former subspecies of the Bornean slow loris were elevated to species status, and a new species—N. kayan—was recognized among the Bornean population.

Nycticebus linglom is a fossil strepsirrhine primate from the Miocene of Thailand. Known only from a single tooth, an upper third molar, it is thought to be related to the living slow lorises, but the material is not sufficient to assign the species to Nycticebus with certainty, and the species name therefore uses open nomenclature. With a width of 1.82 mm, this tooth is very small for a primate. It is triangular in shape, supported by a single root, and shows three main cusps, in addition to various crests. The absence of a fourth cusp, the hypocone, distinguishes it from various other prosimian primates.

<span class="mw-page-title-main">Conservation of slow lorises</span> Conservation management of the nocturnal primates in Asia

Slow lorises are nocturnal strepsirrhine primates in the genus Nycticebus that live in the rainforests of South and Southeast Asia. They are threatened by habitat loss and fragmentation from deforestation, selective logging, and slash-and-burn agriculture, as well as by collection and hunting for the wildlife trade, including the exotic pet trade, and for use in traditional medicine and as bushmeat. Because of these and other threats, all five species of slow loris are listed as either "Vulnerable" or "Endangered" by the International Union for Conservation of Nature (IUCN). Their conservation status was originally listed as "Least Concern" in 2000 because of imprecise population surveys and the frequency in which these primates were found in animal markets. Because of their rapidly declining populations and local extinctions, their status was updated and in 2007 the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) elevated them to Appendix I, which prohibits international commercial trade. Local laws also protect slow lorises from hunting and trade, but enforcement is lacking in most areas.

<i>Nycticebus kayan</i> Species of primate

The Kayan River slow loris is a strepsirrhine primate and a species of slow loris that is native to the northern and central highland region of the island of Borneo. The species was originally thought to be a part of the Bornean slow loris (N. menagensis) population until 2013, when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it. It is distinguished by the high contrast of its black and white facial features, as well as the shape and width of the stripes of its facial markings.

The Bangka slow loris is a strepsirrhine primate and a species of slow loris that is native to southwestern Borneo and the island of Bangka. Originally considered a subspecies or synonym of the Bornean slow loris (N. menagensis), it was promoted to full species status in 2013 when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it as a separate species. It is distinguished by the crimson red fur on its back, light-colored facial features, as well as the shape and width of the stripes of its facial markings.

<i>Nycticebus borneanus</i> Species of primate

Nycticebus borneanus, the Bornean slow loris, is a strepsirrhine primate and a species of slow loris that is native to central south Borneo in Indonesia. Formerly considered a subspecies or synonym of N. menagensis, it was promoted to full species status in 2013 when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it as a separate species. It is distinguished by its dark, contrasting facial features, as well as the shape and width of the stripes of its facial markings.

References

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Literature cited