After not being documented for nearly three decades, many scientists feared the worst for the silver-backed chevrotain, a desperately cute species of mouse-deer that cautiously roamed the jungles of Vietnam.
But now, a team of researchers has captured the first photographs of the species in the wild, categorically proving that the oh-so-shy species is still alive.
Reporting in the journal Nature Ecology & Evolution this week, researchers from Global Wildlife Conservation in Texas and the Vietnam Academy of Science and Technology used dozens of camera traps to capture images of numerous silver-backed chevrotains in the coastal forested areas around Nha Trang in southern Vietnam.
"The species had been on our radar for a few years. Nothing was known about it, including whether or not it was still out there, so we always wanted to unravel this mystery," study author Andrew Tilker, Asian Species Officer at Global Wildlife Conservation, told IFLScience.
Chevrotains, also known as mouse-deer, are a family of small ungulates (hoofed mammals) that consists of at least 10 different species. The silver-backed chevrotain (Tragulus versicolor), also known as the Vietnam mouse-deer, is one of the rarest species of this family. It's about the size of a large rabbit, has tusk-like fangs in lieu of horns, and is characterized by its unique silvery-gray coloration. Its scarcity has earned itself the title of one of the world’s “most wanted lost species” by Global Wildlife Conservation's Search for Lost Species initiative.
Other than the four specimens that were used to describe the species in 1910, only a single verifiable record of the species exists. The last official documentation of a silver-backed chevrotain was in 1990 when a hunter shot and killed an individual in the vicinity of Dak Rong and Buon Luoi. Given the high levels of snare hunting in the area, it was feared that the species might have been "lost to science."
Nevertheless, a sprinkling of reports continued to persist in parts of Vietnam over the past few decades. This prompted the team to interview a number of local people living across three Vietnamese provinces in an attempt to pindown its potential whereabouts.
"It has gone unrecorded by scientists for almost 30 years – but local people were, of course, aware of it all along. That’s why we say it has been 'lost to science.' That said, the primary reason it went undocumented by biologists appears to be simply because nobody had looked for it. The silver-backed chevrotain was truly an overlooked species," Tilker explained.
Based on these conversations, the team placed more than 30 motion-activated camera traps within the dry coastal forested areas in the vicinity of Nha Trang. Their sleuthing paid off: between April and July 2018, they captured 1,881 photographs of silver-backed chevrotain, comprising 208 independent events.
Although it's unclear how many individuals exist in the wild, the researchers were blown away by the optimism their results suggested.
"From our interviews, we have reliable reports of a gray-colored chevrotain from a second forest area. We are planning follow-up surveys now to try to determine if this could be a second population," Tilker added. "We also have a good idea of other places we would search for the species, based on the limited information we currently have. It may be that the species is relatively common across a fairly large part of Vietnam."