Research | IZW | 01-01-2020

Rediscovery of the silver-backed chevrotain

The silver-backed chevrotain, also called the Vietnamese mouse deer, was thought to be extinct. But now, 28 years after it was last recorded, researchers have photos and footage confirming the first rediscovery of this shy creature in the wild.

Alexis Rockman for Global Wildlife Conservation

Photos and footage of the silver-backed chevrotain – a deer-like species that is the size of a rabbit – have been captured on camera traps in southern Vietnam. This species was last recorded in 1990 and is the first mammal on Global Wildlife Conservation’s (GWC) “25 Most Wanted Lost Species” list to be rediscovered. The rediscovery has now been published in the scientific journal Nature Ecology & Evolution and is spurring on efforts to protect the chevrotain and other native (endemic) species in this biodiversity hotspot of Southeast Asia.

“We had no idea what to expect, so I was surprised and overjoyed when we checked the camera traps and saw photographs of a mouse deer with silver flanks,” said An Nguyen, associate conservation scientist for GWC and expedition team leader. Nguyen is also a PhD student with the Leibniz Institute for Zoo and Wildlife Research. “For so long, this species has seemingly only existed as part of our imagination. 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.”

The silver-backed chevrotain was described in 1910 from four individuals collected from southern Vietnam. A Russian expedition to central Vietnam in 1990 collected a fifth individual. Scientists know almost nothing about the general ecology or conservation status of this species, making it one of the highest mammal conservation priorities in the Greater Annamite mountains, one of GWC’s focal wildlands. There are ten known species of chevrotains in the world, primarily from Asia. Despite their common English names, chevrotains are neither mice nor deer, but the world’s smallest ungulates (hoofed mammals). They are shy and solitary, appear to walk on the tips of their hooves and have two tiny fangs. Chevrotains typically weigh less than 5 kg.

After several interviews with local villagers and government forest rangers who reported seeing a gray mouse deer— the color distinguishing the silver-backed chevrotain from the more common lesser mouse deer—the field team set three camera traps for five months in an area of southern Vietnam where locals indicated they may have seen the animal. This resulted in 275 photos of the species. The team then set up another 29 cameras in the same area, this time recording 1,881 photographs of the chevrotain over five months. “The rediscovery of the silver-backed chevrotain provides a big hope for the conservation of biodiversity, especially threatened species, in Vietnam,” said Hoang Minh Duc, head of the Southern Institute of Ecology’s Department of Zoology. “This also encourages us, together with relevant and international partners, to devote time and effort to further investigate and conserve Vietnam’s biodiversity heritage.”

Camera-trap evidence that the silver-backed chevrotain Tragulus versicolor remains in the wild in Vietnam.
Nguyen A, Tran VB, Huang MD, Nguyen TAM, Nguyen DT, Tran VT, Long B, Meijaard E, Holland J, Wilting A, Tilker A (2019) Nature Ecology & Evolution.
doi: 10.1038/s41559-019-1027-7

Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW)

An Nguyen
Doctoral student and Field Coordinator in the Department of Ecological Dynamics
Phone +84 906795984

Andrew Tilker
Doctoral student in the Department of Ecological Dynamics
Phone +49 30 5168-335

Dr. Andreas Wilting
Senior Scientist in the Department of Ecological Dynamics
Phone +49 30 5168-333

Jan Zwilling
Science Communication
Phone +49 30 5168-121