The pictures of the rabbit-sized animal, also known as the silver-backed chevrotain, are the first to be taken in the wild and come nearly 30 years after the last confirmed sighting.

“We had no idea what to expect, so I was surprised and overjoyed when we checked the camera traps and saw photographs of a chevrotain with silver flanks,” said An Nguyen, a scientist and expedition team leader at Global Wildlife Conservation (GWC).

“Discovering that it is, indeed, still out there is the first step in ensuring we don’t lose it again, and we’re moving quickly now to figure out how best to protect it,” he said.

The silver-backed chevrotain is a half-painted beast. Behind the russet head, neck and front legs lies a silver-grey body and hind legs rounded off by a white, grizzled bottom. Though probably preyed on by leopards, wild dogs and pythons, scientists fear that snares laid by hunters have pushed the species to the brink of extinction. Despite the name, they are neither mice nor deer, but the world’s smallest ungulate, or hoofed animal.

Nguyen and his team began their search by interviewing villagers and government forest rangers in provinces of Vietnam where the animals had previously been spotted. Some recalled seeing grey chevrotains, suggesting the species might not have died out in the wild.

Based on the information, the scientists installed three camera traps in a lowland forest in southern Vietnam. Over five months, they captured 275 photos of the animal. These were classified as 72 separate events, since multiple photos taken within the space of an hour are considered one event. Buoyed by the sightings, the researchers set up a further 29 cameras in the same area and took 1,881 more photographs, comprising 208 independent events. It is unclear how many individual animals the photographs represent.

The findings, reported in Nature Ecology and Evolution, have increased calls for swift action to protect what remains of the population. A chief priority is to reduce the widespread use of snares to capture animals for the wildlife trade. “Stopping snaring will not only protect the silver-backed chevrotain, but also numerous other species, including several mammals and birds that are only found in the Greater Annamites ecoregion and are threatened with extinction,” said Andrew Tilker, a member of the GWC team.

The rediscovery of the silver-backed chevrotain has raised hopes that other species thought lost to science could yet be found in the wild.

“A key aspect to future surveys for lost species will be to work with local communities, as we did for the silver-backed chevrotain project, to help guide on-the-ground survey efforts,” said Tilker. “Incorporating this local ecological knowledge was critical for our work, and this strategy could prove successful for other species in other parts of the world.”