Tragulus versicolor, Thomas, 1910

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 : 330

4.

Silver-backed Chevrotain

Tragulus versicolor

French: Chevrotain du Vietnam / German: Annam-Kantschil / Spanish: Ciervo ratdn plateado

Taxonomy. Tragulus versicolor Thomas, 1910 ,

Nhatrang, Annam, Viet Nam. This species 1 monotypic.

Distribution. If still extant, the species would likely occur in Vietnam, and possibly in neighboring Cambodia and Laos. The true distribution of the species is unknown, because there has been very little awareness of the species. Surveys have not sought it, because many have assumed that only one species, Tragulus kanchil , occurs in most of Indochina.

Descriptive notes. Head-body 40 cm, tail 5 cm, hindfoot 11 cm, ear 3-5 cm; weight 1-7 kg (all measurements from one specimen). The upperparts of 7. versicolor have a characteristic shabrack or saddlecloth appearance. The fur on the back is uniformly grayish-silver and relatively dense; the hairs are conspicuously tipped with white. The area of the neck and shoulders, although quite uniform in color, is visibly separated from the back in having more brownish and less dense fur. Thesides of the neck possess a somewhat different pattern of pelage structure. The fur of the neck appears to have a coarser, less spiny appearance compared to the sympatric 7. kanchil . This coarse hair was one of the characteristics used to describe the species initially. There are no dark lines from the eye to the nose. Some specimens have a throat pattern with three white and two colored stripes, which are characters of 7. kanchil , whereas there are others with the napwlike five white and four dark stripes. The white area of the underparts in 1. versicolor continues uninterrupted from the chin towards the groin area, and there is no transverse brownish collar below the throat, unlike most other Tragulus species. Also, there are no darker-colored markings along the sides and midlines of the belly, which are characteristic of 71. kanchilin Vietnam. The skull of 7. versicolor is significantly smaller than in all other Tragulus species , but relatively wide, with wide bullae and very long nasals. Compared to T. napu and T. kanchil , the large auditory bullae are much more rounded and inflated. Dental formulais10/3,C1/1,P 3/3, M 3/3 (x2)= 34.

Habitat. Because no specimens have been traced to specific habitats, and there are no observations of the species in the wild, nothing is known about its habitat preferences.

Food and Feeding. Nothing known.

Breeding. Nothing known.

Activity patterns. Nothing known.

Movements, Home range and Social organization. Nothing known.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. There is no information on the current range or population status of 7. versicolor because of a lack of survey work for the species in appropriate areas of Vietnam. Therefore the species cannot be assessed against range size or population trend criteria. No strong ecological correlates are sufficiently known to allow assessment of population trends through habitat trends. The species’ resilience to hunting is not known. Although there is only one record since 1907, there is no reason to consider it a possibly Extinct candidate, because the paucity of records is assumed to reflect the lack of suitable surveys. A more informed judgment when sufficient data are available is likely to indicate that it is threatened. The population is almost certainly declining due to severe hunting pressure for ground-dwelling mammals, resulting in population reductions of even the most resilient species; it may be found to warrant a very high threat category, particularly as there is no evidence of presence in high altitudes.

Bibliography. Kuznetsov & Borissenko (2004), Meijaard & Groves (2004a, 2004b), Meijaard et al. (2004), Thomas (1910), Timmins et al. (2008).

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. If still extant, the species would likely occur in Vietnam , and possibly in neighboring Cambodia and Laos . The true distribution of the species is unknown, because there has been very little awareness of the species. Surveys have not sought it, because many have assumed that only one species, Tragulus kanchil , occurs in most of Indochina.