when we first went out, we had no idea snow leopards would become our life's work," says writer Darla Hillard. But that changed in 1981 when Darla and wildlife biologist Rodney Jackson undertook the first scientific expedition to radio-collar and study the big cat, in western Nepal's remote Kanjiroba Himal. The idea of studying snow leopards, one of the least-known endangered species, seemed only slightly less kooky than putting out a search for a yeti.

The couple was in Kathmandu this week to re-launch Vanishing Tracks: Four Years Among the Snow Leopards of Nepal, Darla's seminal account of their work between 1981 and 1985. Armed with a research grant from the Rolex Awards for Enterprise, Rodney and Darla put together a team and spent harsh winters and balmy springs in the Langu Gorge that is now in Shey Phoksumdo National Park.

They captured, collared and released five cats, imaginatively named Ek, Dui, Teen, Char and Panch. They had up-close and personal photographs of all five leopards.

Vanishing Tracks is still the major reference work on the species and reveals much about the elusive creature's life in the wild. The first fruit of Darla and Rodney's undertaking was a National Geographic cover story on snow leopards that reached 11 million readers. The second edition of Vanishing Tracks, published with Mandala Book Point, includes an updated bibliography and foreword, and outlines the developments in snow leopard conservation.

The two now run the group Snow Leopard Conservancy and are engaged in grassroots conservation activities in Tibet, Ladakh, Mongolia, and in the Indian and Nepal Himalaya.

Local people need to be trained as "community wildlife stewards" for conservation to be successful, says Rodney. "The only way to make this happen is by blending traditional knowledge with science," he adds.

In order to check retributive killings by angry farmers whose livestock snow leopards sometimes prey on, the Conservancy is helping locals build predator-proof corrals and pens in places like Upper Mustang.

The group also helps educate locals in improving animal husbandry and developing alternative income-generating activities such as handicrafts, cheese-making and tourism. Later this year they will begin a program in Manang to use tourism as an incentive for conservation.