It's the beginning of winter, high up on the Tibetan plateau
The temperature will soon drop to minus 40 Celsius
Out here,life is reduced to a single imperative - survival
For the argali, the world's largest sheep
it means searching for a few tufts of grass
Descending from the hilltops to lower altitudes the argali band together for safety
Hopefully, down here,they'll be able to find enough food to last them through the rest of the winter
Although this winter landscape looks barren and forbidding
Tibet's remote grasslands support a surprising variety of creatures
Though at this time of year, they can be hard to track down