March 2003 Vietnam's Secret Life Naturalists exploring the country's mountains and forests are finding that the keys to its extraordinary biodiversity may lie deep in the past. By Eleanor J. Sterling, Martha M. Hurley, and Raoul H. Bain Along Vietnam's border with Laos runs the Truong Son range, known to the Laotians as Saiphou Louang and to much of the rest of the world as the Annamites. But the mountains are becoming known—to conservation biologists as well as to everyone else concerned with preserving the world's species—as a region of exceptional biodiversity. In the early 1990s investigators began visiting Vietnam's natural areas in greater numbers than at any time since the beginning of what is known to the people of the region as the Second Indochina War. And the investigators—ecologists, evolutionary biologists, and specialists in a broad spectrum of life-forms—soon confirmed what the local peoples had long known: an astounding array of organisms dwell in the country. For many biologists to this day, entering Vietnam is like entering uncharted territory, an area of vast biological abundance, where new species, it seems, can turn up virtually anywhere you look. Biologists exploring the Truong Son have discovered—or, importantly, rediscovered—three previously unrecognized species of muntjac, or barking deer; one species of pig; and one species of rabbit. Those findings alone are remarkable; after hundreds of years of systematic biology, who would have thought that large or medium-size mammals would remain to be described? And that list doesn't even include the saola, the sole member of , a genus entirely new to the cattle family. Weighing in at about 220 pounds, the saola is the largest land-dwelling mammal introduced to science since the kouprey, or gray ox, was described in 1937. (That animal ranged through northern Cambodia and adjacent areas of Thailand, Laos, and Vietnam, but may now be extinct.) Pseudoryx But Vietnam promises more to biologists than just the windfall that is the Truong Son range. Ever since the mid-nineteenth century, up until the beginning of the Second World War, forays by Vietnamese and visiting naturalists had sketched a spotty but telling portrait of the country's biodiversity. More recently, since peace came to Vietnam, further hints of biological abundance have come from collaborations between Vietnamese and foreign investigators. But only in the past ten years have biologists understood that the newly recognized charismatic megafauna are only the tip of an iceberg of heretofore unknown species that live in the Truong Son as well as in other, primarily montane, areas of Vietnam. Among the The Sichuan whipping frog has been assigned to the species —but herpetologists are now realizing that these frogs actually form a group of species, not just one. The several species probably arose when climate change stranded ancestral frog populations on separate mountaintops; the confusion for zoology arose when the climate changed again, first warming and then cooling, enabling the new (but similar looking) frog species to disperse before they were isolated once more. Polypedates dugritei Photo by Raoul H. Bain After hundreds of years of systematic biology, who would have thought that large or medium- size mammals would remain to be described? Naturalists exploring the country's mountains and forests are finding that the keys to its extraordinary biodiversity may lie deep in the past. By Eleanor J. Sterling, Martha M. Hurley, and Raoul H. Bain Along Vietnam's border with Laos runs the Truong Son range, known to the Laotians as Saiphou Louang and to much of the rest of the world as the Annamites. But the mountains are becoming known—to conservation biologists as well as to everyone else concerned with preserving the world's species—as a region of exceptional biodiversity. In the early 1990s investigators began visiting Vietnam's natural areas in greater numbers than at any time since the beginning of what is known to the people of the region as the Second Indochina War. And the investigators—ecologists, evolutionary biologists, and specialists in a broad spectrum of life-forms—soon confirmed what the local peoples had long known: an astounding array of organisms dwell in the country. For many biologists to this day, entering Vietnam is like entering uncharted territory, an area of vast biological abundance, where new species, it seems, can turn up virtually anywhere you look. Biologists 3/11/03 11:58 AM Natural History Magazine | Feature Page 1 of 6 http://www.amnh.org/naturalhistory/0303/0303_feature.html