Tragulus javanicus (Osbeck, 1765)

Don E. Wilson & Russell A. Mittermeier, 2011, Tragulidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 320-334 : 331-332

7.

Javan Chevrotain

Tragulus javanicus

French: Chevrotain de Java / German: Java-Kantschil / Spanish: Ciervo ratén de Java

Taxonomy. Cervus javanicus Osbeck, 1765 ,

Udjung Kulon Peninsula , Java, Indonesia .

Craniometrical analysis indicates that there may be two distinct chevrotain taxa on Java. The data are, however, inconclusive. Further research, particularly on skin patterns ofJavan Chevrotain, is required. None of the specimens originally used to describe two subspecies, the gray-necked form pelandoc (from the north coast of West Java Province) and the red-necked form focalinus (from the western part ofJava and to the southern coast), were included in a recent taxonomic review of the genus. An earlier review found all kinds of forms that were intermediate between the two supposed Javan subspecies and concluded that there was probably only one taxon on Java. Monotypic.

Distribution. Java. Several biogeographic reviews failed to list the genus for Bali, an island directly east of Java with strong biogeographic affinities to the latter. A sighting was, however, reported from Bali Barat National Park, in a birdwatching trip report. Given the live-animal trade of this species on Java, further records are needed to confirm whether or not there is a native population of the genus on Bali. If there is, biogeographic considerations suggest it would be most closely related to the Javan population and quite probably conspecific.

Descriptive notes. Head-body 50-53 cm,tail 4-6 cm; weight 1.7-2. 1 kg. Compared to 1. kanchil , T: javanicus is distinguished by its narrow auditory bullae, narrow braincase, and longer and higher mandibles. Compared with 7. kanchil from nearby Sumatra, the rostrum is shorter and the auditory bullae are narrower. Two different taxa of chevrotain have been described from Java, a gray-necked form and a red-necked form. The gray-necked form was distinguished from all other 7. javanicuslike chevrotains by the great width and distinctness of the tawny superciliary stripes and by the grizzled gray neck, which is strikingly contrasted with the tawny body and head; in addition, the nape stripe is absent, although the dark crown sometimesslightly extends onto the nape. The red-necked form, described on the basis of five specimens in the Zoological Museum of the Humboldt University in Berlin, has an orange-brown ground color,slightly grizzled with black. All five specimens had a clear, almost black, nape stripe. The cheeks and the sides of the neck are orange-buff, as opposed to the gray in the gray-necked form. This species was described as having a remarkably long tongue, which “it brings with ease to behind its ears,” but presumably this is a generic rather than species-specific characteristic. Dental formulais 10/3; C1/1; P 3/3; M 3/3 (x2)= 34.

Habitat. Preferred habitat of the Javan Chevrotain includes evergreen and semi-evergreen rainforest. The species has been reported in the drier semi-deciduous forests of eastern Java, butit seems to be rarer there than in the wetter forests of central and west Java. One habitat-use study suggested that 7. javanicus uses dense bushes and stands of Salacca zalacca palms during the day. It generally remains not far from rivers. This suggests that chevrotains there might be an “edge” species, apparently preferring areas with thick understory vegetation, such as that along riverbanks. This would not be unusual within the genus (see other Tragulus accounts). The species occurs from sea level to about 1600 m above sea level in the mountains.

Food and Feeding. In captivity Javan Chevrotains refuse grass as fodder and do not feed on any grasses that grow in their cages. Instead they are kept on banana peels, jackfruit, and the left-overs of rambutan and mangosteen fruits. In captivity, they are partial to leaves of a number of Acalypha (Euphorbiaceae) species, including A. marginata and A. wilkesiana, as well as leaves of Laeucaena glauca, Ipomoea batatas, I. reptans, and Manihot utilissima . In the wild, the species reportedly feeds on fallen fruit, including wild figs (Ficus spp.), and the leaves and buds of a variety of plants.

Breeding. Males ofthis species are reported to produce unusual screams during the mating season. In captivity they have been observed to fight to the death. With bared teeth (lips withdrawn) males circled each other, and by approaching from the side, tried to get underneath the opponentto stab or slice with their canines. As a result, the belly of one victim was ripped open, causing its entrails to spill. The female had calmly observed the fight, lying down with the front legs folded underneath her body; mating with the winning male took place soon after. Females in captivity developed bold patches, sometimes chafed and bloody, after mating, apparently caused by the sharp hooves of the male during copulation. Gestation lasts several months, after which one young is born, “the size of a rat”, dark brown, with a very small head and thin legs. Young can run and jump soon after birth, and suckle only occasionally, only at night and very briefly. The young soon start eating the same leaves and fruits as older animals. Neither male nor female parent made any apparent effort to protect their young. A specimen of 7. javanicus successfully bred with a chevrotain from Bangka Island (presumably 7 kanchil luteicollis) and produced a young with intermediate characteristics.

Activity patterns. Observations in captivity suggest that the species is nocturnal, and during the day rests in a quiet, cool, shaded spot. It becomes active around 16:00 h or 17:00 h in the afternoon.

Movements, Home range and Social organization. Nothing known.

Status and Conservation. The account of 7. javanicus on The IUCN Red List states that the speciesis classified as Data Deficient, partly reflecting the lack of clarity over how many species of chevrotain occur onJava and therefore how much of the available information about the genus refers to 1. javanicus . The authors mention that there are fair indications of a decline, perhaps a major one, and a category such as Vulnerable is quite likely to be applicable. The species is hunted for meat and is also often sold as a pet, for example in markets in West Java. In the 1920s it was reported that the species was commonly trapped using snares, but no recent information on this is available. Dedicated field investigations (throughoutJava) ofstatus are urgently warranted, and the Red List status of the species should be reviewed regularly in light of current uncertainty and concerns.

Bibliography. Dakkus (1932), Dobroruka (1967), Doctors van Leeuwen (1921), van Dort (1986, 1988), Duckworth et al. (2008), Farida (2003), Groves & Meijaard (2005), Hoogerwerf (1970), Meijaard & Groves (2004a, 2004b), Supraptomo (1953), van der Vegte (1938).

Figures

1. White-spotted Chevrotain (Moschiola meminna), 2. Yellow-striped Chevrotain (Moschiola kathygre), 3. Indian Chevrotain (Moschiola indica), 4. Silver-backed Chevrotain (Tragulus versicolor), 5. Lesser Indo-Malayan Chevrotain (Tragulus kanchil), 6. Northern Chevrotain (Tragulus williamsoni), 7. Javan Chevrotain (Tragulus javanicus), 8. Greater Indo-Malayan Chevrotain (Tragulus napu), 9. Balabac Chevrotain (Tragulus nigricans), 10. Water Chevrotain (Hyemoschus aquaticus)

Distribution. Java. Several biogeographic reviews failed to list the genus for Bali, an island directly east of Java with strong biogeographic affinities to the latter. A sighting was, however, reported from Bali Barat National Park, in a birdwatching trip report. Given the live-animal trade of this species on Java, further records are needed to confirm whether or not there is a native population of the genus on Bali. If there is, biogeographic considerations suggest it would be most closely related to the Javan population and quite probably conspecific.