Attenborough's Long-beaked Echidna_Alexis Rockman.jpg

Silver-backed Chevrotain

scientific name: Tragulus versicolor

Last seen: 1990 in Vietnam

Years lost: 27

Expedition team members include:
An Nguyen, Barney Long and Andrew Tilker

Expedition Funding Provided by:

zoo-logo.png
 

At a Glance:

Finding the Silver-backed Chevrotain, a deer-like species the size of a rabbit or small cat, is one of the highest mammal research priorities in the Annamite Mountains. There’s only been one record of the species since 1907—a specimen purportedly collected from Vietnam’s southern coast, near Nha Trang. It has not been reported from anywhere else in Southeast Asia and scientists known nothing about its ecology or conservation status. If the species still exists, populations have undoubtedly declined through ongoing hunting. Chevrotains are also known as mouse deer. 

A Closer Look:

“It may be that when we look for the Silver-backed Chevrotain, it’s quite easy to find. Or it might be one of those species that we look for that is never found again. Either way, it’s worth a try. It will be an amazing feat to go from complete non-understanding of the Annamites 25 years ago to now having this question mark resolved.”

-Barney Long, Global Wildlife Conservation director of species conservation and expedition member

Our knowledge of the ecology and distribution of the Silver-backed Chevrotain is a bit of black hole. What we think we know about the natural history of the species is primarily based on what we know generally about chevrotain species—they’re small ungulates (hoofed mammals) that are shy and solitary and feed on plants. They’re usually reddish brown in color with striped and spotted fur. They appear to walk on their tippy toes (the tips of their hooves) and they are among the smallest of ungulate species. 

We know we have at least one record of the species from an expedition that collected specimens around 1910. We know that a Russian expedition claimed to have collected a specimen in 1910, but the photos aren’t conclusive. 

While the 1910 record indicates that Silver-backed Chevrotains may live in coastal areas, there’s no conclusive evidence that this is the case. If they instead live in deeper evergreen rainforest areas, they’re likely the victim of rampant and indiscriminate snare hunting throughout the Annamites, one of Global Wildlife Conservation’s priority wildlands. This poaching has devastated populations of other Annamite endemics, including Saola and Large-antlered Muntjac and left the forests empty. Scientists aren’t even sure that the Silver-backed Chevrotain still exists—and if it does, where and to what extent.

“It’d be amazing to find the Silver-backed Chevrotain, but that’s just the first step,” says Barney Long, Global Wildlife Conservation director of species conservation and expedition member. “No matter where it’s found, it’s going to be under severe threat, so its discovery will spur conservation action. We need to identify not just one individual on camera trap, but one or two sites with populations that we can actually protect.”

Determining the best place for an expedition to look for the Silver-backed Chevrotain will rely on surveys with locals, including hunters and rangers, though efforts to verify sightings will be complicated by the fact that there’s another chevrotain in the area, the Lesser Mouse Deer, that looks very similar. The expedition team will also look for specimens in the market and trophies in villages as evidence that the species may still be around. A photo of a juvenile chevrotain collected a few years ago from a park in Vietnam provides the team with some direction, but there’s no way to confirm that the juvenile is the Silver-backed Chevrotain specifically. 

If the researchers are then able to identify a few forest blocks that could harbor the species based on the interviews with locals, they will launch an expedition primarily with the use of camera traps to capture evidence of the species. They’ll use spotlights to try to see it live, and may use DNA analysis to confirm that the chevrotain is, indeed, the long-lost silver-backed species and not the Lesser Mouse Deer.

“It seems like this long-lost chevrotain just never got the attention it deserves,” says Andrew Tilker, Global Wildlife Conservation associate conservation scientist and expedition team member. “I’m hoping that by rediscovering it, putting it back on the map, we’ll draw more attention to the endemic mammal community in the Annamites. We want to show how incredibly special and fragile this community is.”