But for more than 20 years political instability in Tajikistan and Afghanistan prevented Schaller from surveying the wildlife there.

In 2003 he was able to join several local biologists on a Marco Polo sheep survey in Tajikistan. They found that the sheep population there might have shrunk to as few as 10,000 animals.

Schaller says indiscriminate hunting by poor livestock herders, as well as border officials and the military, is to blame.

"Local people have nothing—they have to sell livestock to get food," he said.

"To get meat, they go out and hunt Marco Polo sheep."

Deep Snow

The severe toll that hunting has taken on the Marco Polo sheep again became clear when Schaller finally got to visit Afghanistan's Wakhan Corridor in late 2004.

In pursuit of the massive animals, which can weigh more than 300 pounds (135 kilograms), Schaller and his colleagues often observed only the flash of white rumps a ... Читать дальше »