A species of mouse-deer undocumented for almost 30 years has been rediscovered in the lowland forests of Vietnam. The silver-backed chevrotain, about the size of a small cat, had never been photographed in the wild and is only known to science thanks to five specimens, four of which were described in 1910. The fifth specimen, a pelt from a hunter-killed chevrotain, was described in 1990. The species appeared to be extinct, felled by deforestation and intensive hunting over the last century.
On Monday in the journal Nature Ecology and Evolution, scientists announced the discovery of a population of silver-backed chevrotain, detailing an expedition to Vietnam's Greater Annamite region. An intense period of study and field work resulted in the first detection of the species in nearly three decades.
It's another success story for Global Wildlife Conservation, a non-profit collaborating with conservation scientists to search for lost species. In February, the organization and researchers from the University of Sydney announced. That enormous buzzer hadn't been seen for 38 years.
To find the chevrotain, field biologist An Nguyen and a team of researchers conducted a series of surveys across 13 Vietnamese villages and towns. The silver-backed chevrotain has a distinctive ochre-and-grey fur and the team surmised if the species was alive, local residents would be able to recall the species' unique look.
"The species has been known to local people all along," says Andrew Tilker, a conservationist with Global Wildlife Conservation and author on the new study. "In this respect, the silver-backed chevrotain was a species that was "lost to science," but it was not lost to local people living in and around its habitat."
The initial surveys helped researchers decide where to build a network of camera traps across the forests in Vietnam's south.
The traps were programmed to take a three-shot burst when triggered by motion and ran over two study periods, lasting approximately six months, in 2017 and 2018. During the observation period, the cameras snapped over 200 images of the silver-backed chevrotain at 15 different locations.
Though the photographs show the species is alive -- the first time ever -- the researchers did not detail the new population, fearing this information may be used by poachers.
Poaching presents one of the greatest threats to the species' existence, along with habitat loss. The researchers urge "immediate follow-up action" and suggest conducting additional surveys across Vietnam's Greater Annamite region to establish other locations where the silver-backed chevrotain may be hiding.
"It is important that scientists conduct follow-up surveys to search for additional populations, assess how common or rare the species is in places where it occurs, and to assess the major threats that it faces," says Tilker. "The involvement of local people will be critical in all of these efforts."
Originally published 8 a.m. PT: Added Tilker comments.