The silver-backed chevrotain is one of the most enigmatic ungulates in the world. Prior to 2018, this species was known only from five museum specimens - four collected between 1906 and 1910 and a single specimen from 1990. No live animals have ever been examined by a biologist, although in April 2018 the first ever photographs of living animals were obtained through the use of remote-sensor cameras in the coastal forests of southeastern Vietnam. Once considered to be a subspecies of greater Malayan chevrotain (Tragulus napu), the silver-backed chevrotain is now widely recognized as a species unto itself.

Head and body length: 40-48 cm

Tail length: 5 cm

Adult weight: 1.7 kg

Based on a very limited sample, the silver-backed chevrotain appears to be generally smaller than the lesser Malayan chevrotain (Tragulus kanchil) which is also found in Vietnam. As the name suggests, the hindquarters of this species are gray, extending from behind the shoulders to the rump and sometimes described as a "saddle." These gray hairs have white tips, imparting a slightly grizzled appearance. The head, neck, and shoulders, in contrast, are bright golden brown, save for the nape of the neck which is washed with dark gray. The hair on the neck is particularly long and coarse. The golden-colored throat is marked with three thick white stripes which radiate from the pale underside of the jaw; the central stripe continues uninterrupted to join the white belly. The tail is white underneath; its upper parts are silvery, transitioning to golden near the tip. All four legs are yellowish-brown. The rounded ears are large and grayish brown, and there are no distinctive facial markings. Males develop long, tusk-like upper canine teeth which protrude from the mouth.

Similar species

• The two-toned body coloration of the silver-backed chevrotain readily distinguish this species from all other members of the genus Tragulus; the continuous white stripe from beneath the chin to the belly also appears to be diagnostic.

Nothing known. Presumably similar to other members of the genus Tragulus.

At the time of writing, virtually nothing is known about the habits of this species - most of what is known has been inferred from camera trap images and videos. The silver-backed chevrotain appears to be primarily diurnal, although one museum specimen was purportedly shot at night. Most observations are of single individuals, although 3% of camera-trap events included two chevrotains together. When walking, these chevrotains have a slightly halting manner; the short tail is flicked vertically at intervals.

Family group: Solitary, occasionally observed in pairs.

Diet: Unknown. Likely leaves and fruit, similar to other chevrotains.

Main Predators: Unknown. Presumably most medium- to large-sized carnivores.

The silver-backed chevrotain is definitively known only from dry coastal forest in southeast Vietnam. The majority of specimens have been collected, and more recently observed, near Nha Trang, Khanh Hoa Province. A single specimen was purchased (in 1990) from hunters further north, in Gia Lai province; this lowland region is dominated by semi-evergreen forest with an open understory. However, whether this specimen was collected in this region or transported there is unknown. The approximate range is depicted in the map below.

IUCN Red List: Data Deficient (2015).

CITES Listing: Not listed (2017).

Threats: Presumably hunting, with snares and guns.

The recent rediscovery (2018) near Nha Trang, Vietnam is the first conclusive evidence that the silver-backed chevrotain still survives. The species is in urgent need of proper assessment to determine population size, its geographic distribution, and threats in order to create an effective conservation strategy.

To contribute to the urgent conservation needs for this species, please donate to the silver-backed chevrotain program headed by Global Wildlife Conservation.