Slow loris

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), pygmy slow loris (N. pygmaeus), Javan slow loris (N. javanicus), Philippine slow loris (N. menagensis), Bangka slow loris (N. bancanus), Bornean slow loris (N. borneanus), and Kayan River slow loris (N. kayan). 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 (the various types of galago), 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. Slow lorises have a round head, a narrow snout, large eyes, and a variety of distinctive coloration patterns that are species-dependent. Their arms and legs are nearly equal in length, and their trunk is long and flexible, allowing them to twist and extend to nearby branches. The hands and feet of slow lorises have several adaptations that give them a pincer-like grip and enable them to grasp branches for long periods of time. Slow lorises have a toxic bite, a trait rare among mammals and unique to lorisid primates. The toxin is obtained by licking a gland on their arm, and the secretion is activated by mixing with saliva. Their toxic bite is a deterrent to predators, and the toxin is also applied to the fur during grooming as a form of protection for their infants. The secretion from the arm contains a chemical related to cat allergen, but may be augmented by secondary toxins from the diet in wild individuals. Slow lorises move slowly and deliberately, making little or no noise, and when threatened, they stop moving and remain motionless. Their only documented predators—apart from humans—include snakes, changeable hawk-eagles and orangutans, although cats, civets and sun bears are suspected. Little is known about their social structure, but they are known to communicate by scent marking. Males are highly territorial. Slow lorises reproduce slowly, and the infants are initially parked on branches or carried by either parent. They are omnivores, eating small animals, fruit, tree gum, and other vegetation. Each of the slow loris species that had been identified prior to 2012 is listed as either 'Vulnerable' or 'Endangered' on the IUCN Red List. The three newest species are yet to be evaluated, but they arise from (and further reduce the ranks of) what was thought to be a single 'vulnerable' species. All four of these are expected to be listed with at least the same, if not a higher-risk, conservation status. All slow lorises are threatened by the wildlife trade and habitat loss. Their habitat is rapidly disappearing and becoming fragmented, making it nearly impossible for slow lorises to disperse between forest fragments; unsustainable demand from the exotic pet trade and from traditional medicine has been the greatest cause for their decline. Deep-rooted beliefs about the supernatural powers of slow lorises, such as their purported abilities to ward off evil spirits or to cure wounds, have popularized their use in traditional medicine. Despite local laws prohibiting trade in slow lorises and slow loris products, as well as protection from international commercial trade under Appendix I, slow lorises are openly sold in animal markets in Southeast Asia and smuggled to other countries, such as Japan. Due in part to the large eyes that are an adaptation to their nocturnal lifestyle, they have also been popularized as 'cute' pets in viral videos on YouTube. Slow lorises have their teeth cut or pulled out for the pet trade. They make poor pets as they are nocturnal, have specialized diets, are difficult to care for, and often die from infection, blood loss, improper caring and handling or inadequate nutrition. Slow lorises (genus Nycticebus) are strepsirrhine primates and are related to other living lorisoids, such as slender lorises (Loris), pottos (Perodicticus), false pottos (Pseudopotto), angwantibos (Arctocebus), and galagos (family Galagidae), and to the lemurs of Madagascar. They are most closely related to the slender lorises of South Asia, followed by the angwantibos, pottos and false pottos of Central and West Africa. Lorisoids are thought to have evolved in Africa, where most living species occur; later, one group may have migrated to Asia and evolved into the slender and slow lorises of today. Lorises first appear in the Asian fossil record in the Miocene, with records in Thailand around 18 million years ago (mya) and in Pakistan 16 mya. The Thai record is based on a single tooth that most closely resembles living slow lorises and that is tentatively classified as a species of Nycticebus. The species is named ? Nycticebus linglom, using open nomenclature (the preceding '?' indicates the tentative nature of the assignment). Several lorises are found in the Siwalik deposits of Pakistan, dating to 16 to 8 mya, including Nycticeboides and Microloris. Most are small, but an unnamed form dating to 15–16 mya is comparable in size to the largest living slow lorises. Molecular clock analysis suggests that slow lorises may have started evolving into distinct species about 10 mya. They are thought to have reached the islands of Sundaland when the Sunda Shelf was exposed at times of low sea level, creating a land bridge between the mainland and islands off the coast of Southeast Asia. The earliest known mention of a slow loris in scientific literature is from 1770, when Dutchman Arnout Vosmaer (1720–1799) described a specimen of what we know today as N. bengalensis that he had received two years earlier. The French naturalist Georges-Louis Leclerc, Comte de Buffon, later questioned Vosmaer's decision to affiliate the animal with sloths, arguing that it was more closely aligned with the lorises of Ceylon (now Sri Lanka) and Bengal. The word 'loris' was first used in 1765 by Buffon as a close equivalent to a Dutch name, loeris. This etymology was later supported by the physician William Baird in the 1820s, who noted that the Dutch word loeris signified 'a clown'. In 1785, the Dutch physician and naturalist Pieter Boddaert was the first to officially describe a species of slow loris using the name Tardigradus coucang. This species was based on the 'tailless maucauco' described by Thomas Pennant in 1781, which is thought to have been based on a Sunda slow loris, and on Vosmaer's description of a Bengal slow loris. Consequently, there has been some disagreement over the identity of Tardigradus coucang; currently the name is given to the Sunda slow loris. The next slow loris species to be described was Lori bengalensis (currently Nycticebus bengalensis), named by Bernard Germain de Lacépède in 1800. In 1812, Étienne Geoffroy Saint-Hilaire named the genus Nycticebus, naming it for its nocturnal behavior. The name derives from the Ancient Greek: νύξ, romanized: (nyx), genitive form of νυκτός (nyktos, 'night'), and κῆβος (kêbos, 'monkey'). Geoffroy also named Nycticebus javanicus in this work. Later 19th-century authors also called the slow lorises Nycticebus, but most used the species name tardigradus (given by Linnaeus in 1758 in the 10th edition of Systema Naturæ) for slow lorises, until mammalogists Witmer Stone and James A. G. Rehn clarified in 1902 that Linnaeus's name actually referred to a slender loris. Several more species were named around 1900, including Nycticebus menagensis (originally Lemur menagensis) by Richard Lydekker in 1893 and Nycticebus pygmaeus by John James Lewis Bonhote in 1907. However, in 1939 Reginald Innes Pocock consolidated all slow lorises into a single species, N. coucang, and in his influential 1953 book Primates: Comparative Anatomy and Taxonomy, primatologist William Charles Osman Hill also followed this course. In 1971 Colin Groves recognized the pygmy slow loris (N. pygmaeus) as a separate species, and divided N. coucang into four subspecies, while in 2001 Groves opined there were three species (N. coucang, N. pygmaeus, and N. bengalensis), and that N. coucang had three subspecies (Nycticebus coucang coucang, N. c. menagensis, and N. c. javanicus).