is especially common). Nomadic transhumance is also common in areas of harsh climate, such as Northern Europe and Russia inhabited by the indigenous Sami people, Nenets people and Chukchis. There are an estimated 30–40 million nomads in the world. Pastoral nomads and semi-nomadic pastoralists form a significant but declining minority in such countries as Saudi Arabia (probably less than 3%), Iran (4%), and Afghanistan (at most 10%). They comprise less than 2% of the population in the countries of North Africa except Libya and Mauritania. The Eurasian steppe has been largely populated by pastoralist nomads since the late prehistoric times, with a succession of peoples known by the names given to them by surrounding literate sedentary societies, including the Bronze Age Proto-Indo-Europeans, and later Proto-Indo-Iranians, Scythians, Sarmatians, Cimmerians, Massagetae, Alans, Pechenegs, Cumans, Kipchaks, Karluks, Saka, Yuezhi, Wusun, Jie, Xiongnu, Xianbei, Khitan, Pannonian Avars, Huns, Mongols, Dzungars and various Turkics. The Mongols in what is now Mongolia, Russia and China, and the Tatars or Turkic people of Eastern Europe and Central Asia were nomadic people who practiced nomadic transhumance on harsh Asian steppes. Some remnants of these populations are nomadic to this day. In Mongolia, about 40% of the population continues to live a traditional nomadic lifestyle. In China, it is estimated that a little over five million herders are dispersed over the pastoral counties, and more than 11 million over the semi-pastoral counties. This brings the total of the (semi)nomadic herder population to over 16 million, in general living in remote, scattered and resource-poor communities. In the Middle Hills and Himalaya of Nepal, people living above about 2,000 m practise transhumance and nomadic pastoralism because settled agriculture becomes less productive due to steep slopes, cooler temperatures and limited irrigation possibilities. Distances between summer and winter pasture may be short, for example in the vicinity of Pokhara where a valley at about 800 meters elevation is less than 20 km. from alpine pastures just below the Annapurna Himalaya, or distances may be 100 km or more. For example, in Rapti zone some 100 km west of Pokhara the Kham Magar move their herds between winter pastures just north of India and summer pastures on the southern slopes of Dhaulagiri Himalaya. In far western Nepal, ethnic Tibetans living in Dolpo and other valleys north among the high Himalaya moved their herds north to winter on the plains of the upper Brahmaputra basin