Above the tree line, rhododendron, juniper scrub and other procumbent woody vegetation may extend to about 4200m where it is then succeeded by t a tundra-like association of short grasses, sedge mosses and alpine plants wherever there is sufficient soil. This continues up to the lower limit of perpetual snow and ice at about 5100m. The mammalian faun is sparse and unlikely to include any species other than Himalayan marmots, mouse hare, tahr, musk deer, snow leopard and occasionally blue sheep. In former times, the wild Yak and great Tibetan sheep could also be sighted in this region and it is possible that a few may still be surviving in areas such as Dolpa and Humla. The bird life at such as lammergeyer, snowcock, snowpatridge, choughs and bunting, with redstarts and dippers often seen along the streams and rivulets.
Yaks are the only livestock, which thrive at high altitude.
They serve both back and draught animals. The cheeses prepared out of the milk are edible for months. The female Yak provides milk to the Sherpas. Of the wonderful flora and fauna must suffice to indicate what a paradise Nepal is to the lovers of wild animal and bird life, to the naturalists and to the foresters.