On the trail of new species.(Annamite Mountains of Laos yields previously unknown large mammal species)(Adventure in Laos)

In village huts and markets, scientists are discovering a biological treasure trove that needs protection now

We follow three Hmong tribesmen along a barely discernable trail that traces ridge crests and angles up and down steep slopes. The dense rain forest canopy seals off the sky, leaving the undergrowth of saplings, bamboos and palms in gloom. It is drizzling, as it does much of the time high in the Annamite Mountains of Laos bordering Vietnam. We continuously glance around, hoping to glimpse a saola in the shadows.

The saola, a species of large mammal unknown to science until 1992, was described in nearby Vietnam by biologists Do Tuoc and John MacKinnon after they found several sets of horns in villages. It was the first of an astonish- ing and marvelous assemblage of new mammals that have come to light in the remote and biologically unique Annamites. During the 1990s, in fact, more species of hoofed animals have been discovered or rediscovered here alone than are known to have become extinct worldwide in the past few hundred years. No one except a handful of villagers in the region has ever seen a live saola in the wild.

I am here in this extraordinary biological hot spot on my first of four visits between 1994 and 1997, conducting wildlife surveys in a cooperative venture of New York's Wildlife Conservation Society (WCS) and the Lao Forest Department. My associate, biologist Alan Rabinowitz, and his wife Salisa are along, as are several Laotian colleagues. In addition to finding saola and other creatures, known and unknown, our long-range intent is to help find a way to preserve these magnificent forests and their wildlife. But for now the only wildlife we see are land leeches humping expectantly toward us over the moldering leaves on the forest floor.

The chance of finding new species of large mammals adds a special aura of excitement and anachronistic pleasure to our wildlife surveys. After all, only a few such species have been found this century: okapi, giant forest hog, mountain nyala, Chacoan peccary, bonobo, kouprey. I feel like a nine- teenth-century biologist--but with a difference. Discoveries, I soon learn, are made not in the depths of the forest but in village huts and markets. Wildlife is …