Tragulus napu, F. Cuvier, 1822
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https://doi.org/ 10.5281/zenodo.5721279 |
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https://doi.org/10.5281/zenodo.5721315 |
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https://treatment.plazi.org/id/03C587E3-1E7E-FF91-FF53-F7D79400F884 |
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Conny |
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scientific name |
Tragulus napu |
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Greater Indo-Malayan Chevrotain
French: Chevrotain napu / German: Grofskantschil / Spanish: Ciervo raton grande
Taxonomy. Moschus napu F. Cuvier, 1822 ,
Sumatra, Indonesia.
Restricted by Sody in 1931 to southern Sumatra.
Greater Indo-Malayan Chevrotains are highly variable in coloration, especially the taxa from small islands. This has led to the description of a great number of species and subspecies. A taxonomic review in 2004 brought some clarity about the validity of the many described taxa. Still, many type specimens, especially of small island taxa, were not included in that review and the authors were unable to assess the validity ofall taxa. In addition to the subspecies below several other taxa have been described for which the taxonomic status remains unresolved. This includes nigrocinctus from Malacca Strait islands (Kundur and Karimun Besar = Great Karimon); bullitonus from Belitung Island (which might be a subspecies of 1. kanchil ); amoenus from Musala Island; and several subspecies from island taxa west of Sumatra, including brevipes from Bangkaru Island, russulus and batuanus from Tanahbala and Tanahmasa islands, pinius from Pini Island. All these taxa require further study to determine their taxonomic status. Seven subspecies presently recognized.
Subspecies and Distribution.
T.n.bangue:Chasen&Kloss,1931—BanggiIandBalembanganI,offNBorneo.
T.n.bunguranensisMiller,1901—NatunaIs(=Bunguran),oftWBorneo.
T.n.neubronneriSody,1931—NSumatra.
T.n.nmiasisLyon,1916—NiasI,offWSumatra.
T.n.rufulusMiller,1900—TiomanI,offEMalayPeninsula,RiauandLinggaArchipelagos.
T. n. terutus Thomas & Wroughton, 1909 — Terutau I, off W Malay Peninsula.
The species was recently reconfirmed for Singapore. Maps that include Vietnam, Cambodia, and Laos in the distribution range are based on the earlier assumption that 7. versicolor was a subspecies of 1. napu . Subsequent studies have indicated that 7. versicolor is a distinct species, and that the range of 1. napu therefore does not extend into Cambodia, Laos, and Vietnam. The northern limit on the Thai-Malay peninsula is not well defined. Specimens of 1. napu have been collected from as far north as Bankachon in southern Myanmar (10° 08 ” N), but despite fairly intensive camera-trapping in Kui Buri National Park, Thailand (12° N), 7. napu has not been photographed there. At the northern margin ofits range, it is generally rare. It has been reported, for example, that during the flooding of the Chiew Larn Reservoir (Surat Thani Province; about 9° N, 98° 45’ E), only six 7. napu were rescued compared with 172 71. kanchil . This area is the transition zone from wetter evergreen forest to drier deciduous types, and it might be that 7° napu is not well adapted to the drier forest types towards the northern limit ofits range. There are unconfirmed reports of the species on Java, where it may have been confused with one of the two color morphs of 7. javanicus . As explained in the Taxonomy section, the subspecific status of the populations of several islands remains unclear. View Figure
Descriptive notes. Head-body 42:5-68 cm, tail 8-5 cm, shoulder height 30-35 cm; weight 3-5—4-5 kg. 1. napu is one of the largest Asian chevrotains. The pelage is orangeybrown in color; the hindquarters are lightly mottled with black. The underparts and legs are paler. The underside of the chin is white, and there are a series of white markings on the neck. The head is triangular in shape, and the large black nose is naked. The eyes are very large, and the ears are medium-sized, lightly covered with black hair. The body is rounded, and the rear quarters are higher than the front. The legs are extremely thin and delicate, being about the diameter of a pencil. Compared to the partly sympatric 1. kanchil , skin patterns of 7. napu are more mottled and 7. napu has pale lines on the throat and neck, whereas 7. kanchilnormally has three strong white lines on the throat and has uniformly colored upperparts. There is, however, considerable variation within each species in the coloration and striping patterns (also see other Tragulus species accounts), especially on the many small islands where the species occur. In several instances it is nearly impossible to determine whether a taxon is more closely related to 7. napu or to T. kanchil . In fact, until an in-depth taxonomic review was recently conducted, 7! napu was sometimes considered to be a sibling species of 1. kanchil . The pelage coloration in 7. napu is more variable than in 7 kanchil , with varying degrees of melanism and erythrism. Specimens from the larger islands (Borneo and Sumatra) and the Asian mainland and Malay Peninsula are generally dull yellowish-brown, with a mottled appearance. On several islands, 7. napu typically has a red-brown color. Even the nape-stripe is red-brown, somewhat darker than the orange-red neck. The lines from the eye to nose are deep black, and the red-brown back is mixed with black. From studies of hair and skins and from information in the literature it appears that increased redness is the result of fewer all-black and black-tipped hairs in the coat and possibly also an actual increased redness in the hair pigment. The color pattern of the primitive type of 1. napu on the mainland can be summarized as follows: a mixed brown and black neck, the black concentrating along the nape to form an evident napestripe; and a normal throat pattern with a median white longitudinal stripe, on each side of which is a similar stripe, the three meeting in a broad white mass; the space between median and lateral stripes is brown, as in the side of the neck, or somewhat darker; a brown transverse band or collar separates the stripes from the white of the chest. The two lines of variation are toward predominance of yellowish-brown or toward predominance of black. This species was readily differentiated from members of the 1. javanicus / kanchil group by its larger size, relatively small auditory bullae and, in most specimens, the distinct coat coloration. The analysis of skull measurements suggested that within this species there are three geographical groups, none of which is distinct enough to be assigned to species level. Dental formula: 10/3, C1/1,P 3/3,M 3/3 (x2)= 34.
Habitat. Primary and secondary evergreen rain forest. It has been suggested that the foot morphology of 7. napu indicates a preference for more swampy habitats than 7. javanicus / 1. kanchil . Another source, from Borneo, however, claims that 7. napu is a hill species, found at no great elevation but never on swamps, plains and less often on river banks than 7. kanchil . T. napu seems to be scarcer in logged forest than in primary forest, with an 86% decline in density being reported following timber harvest. Daily home range use also appears to be more extensive in secondary forest. The sensitivity to logging is probably a consequence of diet constraints that limit the species’ ability to compensate for the reduced abundance of selected fruits in disturbed forest by utilizing browsing. In twelve-year-old logged forest, fewer trees remained belonging to genera eaten by 7. napu . On Tioman Island, of the coast of the Malay Peninsula, densities increased away from human settlements probably in direct relationship to hunting pressure; also 83% of observations on this island were in primary forests and 17% in secondary forests or rubber estates.
Food and Feeding. This species is mostly frugivorous, although few details on feeding are known. In captivity they eat most fruits and readily take to bananas, though their favorite food was mentioned to be the fruits and particularly the flowers of “Buah Simpoh” (presumably a Dillenia species). It has been asserted that 7. napu are prone to kill chickens, but no direct evidence for this was found.
Breeding. The species is possibly polygynous; there is no distinct mating season and females give birth throughout the year in Peninsular Malaysia; one or rarely two young are born. The gestation period is 152-155 days. Weaning occurs at 2-3 months. The young reach sexual maturity at 4-5 months, and maximum life span in captivity is reported to be up to 14 years. 1. napu was observed to stamp with one or both hindfeet when slightly alarmed. Other individuals would or would not stamp in response. Both males and females mark objects with the intermandibular gland. Males mark much more frequently than females. Males often lick the urine of females; less frequently, females lick the urine of males. Males court both receptive and unreceptive females. Courting males mark the female on the back or rump with the intermandibular gland and emit a series of squeaks. Females have a postpartum estrus and return to estrus at approximately 14day intervals unless they become pregnant. Females of 7. napu have the potential to be pregnant throughout adult life, often with only 85-155 minutes passing between giving birth and becoming pregnant again. The young are born fully developed, and they are able to stand after 30 minutes. Mothers spend little time with infants. They emit a vocalization that sounds like the squeak of courting males. Both mothers and infants emit a higher-pitched vocalization. Intense agonistic behavior was seen only when strange individuals were introduced into established groups. Males fight by facing each other and biting each other on the ears, neck, and shoulders with their large upper canines. Fighting males usually hold the tail in a vertical position, exposing the white ventral surface, and may emit loud growls. If one male flees, the other pursues and attempts to bite him on the neck and body.
Activity patterns. 7. napu is reported to be cathemeral (active day and night), but there are few data to support this.
Movements, Home range and Social organization. The density of 7. napuin one Borneo site was positively correlated with large strangler fig trees (Ficus spp.) and negatively correlated with grass and herbs and vine tangle. In primary forest densities vary from 37-72 ind/km?®. On Tioman Island, densities ranged from 27-8 ind/km? to 312-5 ind/ km? The home range in primary forest is about 7 ha. Home range and core area size do not differ according to sex, but are determined by body size of the individuals. The species is mostly solitary, with a mean group size of 1-37 individuals. Recent observations indicate that the species escapes predators by hiding under water in forest streams.
Status and Conservation. Classified as Least Concern on The IUCN Red List, because it remains widespread and at least locally common in the Sundaic region and, at least on Borneo, it appears that this species is resilient to hunting, although probably not to habitat degradation. Better data would allow a more confident assessment. Its wide altitudinal tolerance (presumed to be up to 1000 m above sea level) means that it has large populations above the elevation where very rapid forest loss is occurring. The presumed short generation length of the species, which is likely underfive years, also influences assessment, because it means that the species could quickly recover from local declines. Thus, although there may be or may have been drastic local reductions, these have probably not been synchronous over a large enough area to threaten its survival.
Bibliography. Azlan & Engkamat (2006), Chasen (1940), Chua et al. (2009), Dobroruka (1972), van Dort (1986, 1988), Duckworth (1994, 1997), Heydon (1994), Heydon & Bulloh (1997), Matsubayashi & Sukor (2005), Meijaard & Groves (2004a, 2004b), Meijaard et al. (2010), Miura & Idris (1999), Nakhasathien (1989), Payne et al. (1985), Ralls et al. (1975), Smit-van Dort (1989), Timmins et al. (2008), Yasuma (1994, 1996), Yasuma & Andau (2000).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Tragulus napu
| Don E. Wilson & Russell A. Mittermeier 2011 |
Moschus napu
| F. Cuvier 1822 |