Buddhism, while the remainder are Sunni Muslims, whose ancestors settled in Padum and its environs in the 19th century. The majority of Zanskaris are of mixed Tibetan and Indo-European origins; notably Changpa, Dard and Mon. The latter are in fact ethnically Dard, but "Mon" is used in order to distinguish them from later Dard settlers. The population lives mainly in scattered small villages, the largest being the capital Padum, with nearly 700 inhabitants. Most of the villages are located in the valleys of the Zanskar river and its two main tributaries. Given the isolation of this region, the inhabitants tend towards self-sufficiency, and until recently lived in almost complete autarky. External trade has, however, always been necessary for the acquisition of goods such as tools, jewellery, or religious artefacts. The Zanskaris' main occupations are cattle-rearing and farming of land that they almost always own. Cultivable land is scarce, and restricted to alluvial fans and terraces, cultivated fields being rarely found above an altitude of 4,000 metres. The Zanskaris have developed a system of intensive arable agriculture and complex irrigation to produce enough food in these conditions. The scarcity of cultivable land has also resulted in a tendency towards a stable, zero-growth population. An efficient birth-control system in Zanskar has historically been achieved by the common practice of polyandrous marriage, in which several brothers are married to the same wife, and the widespread adoption of a celibate religious life. A high infant mortality rate also contributes to population stability. In the summer, the women and children stay far away from the villages to tend to the livestock. This system, known as transhumance, is similar to the one found in the Alps where the animals are sent during the summer higher up in the mountains (the alpine meadows) and were kept by the children and women. Flora and fauna Much of Zanskar's vegetation is found in the irrigated villages, and on the upper slopes, which receive more precipitation and grow alpine and tundra species. Most impressive are the meadows covered with thousands of edelweiss. At the foot of the Gumburanjon mountain, blue poppies can be found. Crops including barley, lentils, and potatoes are grown by farmers at the lower elevations. Domesticated animals such as the yak, dzo, sheep, horse, and dog are found in the region. Among the wildlife found in Zanskar are the marmot, bear, wolf, snow leopard, bharal, alpine ibex,