In pictures: Tibetan nomads

Jigme's daughter Lhakpa herds the female yaks, or dri, back to the tent for milking. The nomads rely on their herds for all the basics - milk for tea, butter, cheese and yoghurt; dung for fuel; and hair and hide for yarn, rope and clothing.

A poor family may have 20 yaks or fewer; wealthy families up to 500. Jigme has 40.

"We are encouraged by local officials not to have too many yaks but we need a certain number to sustain us," says Jigme.