in Mongolia has increased significantly. Unlike sheep, goats tend to damage the grass by nibbling at its roots; their sharp hooves also damage the upper layer of the pasture, which is subsequently swept away by the wind. This leads to desertification. Mitigation Some traditional methods to protect the livestock from such inclement weather conditions include drying and storing cut grass during the summer months, and collecting sheep and goat dung to build dried flammable blocks called kizyak in Central Asia and аргал (аргал түлш) in Mongolia. Dried grass can be fed to animals to prevent death from starvation when zud occurs. The kizyak, or blocks of sheep and goat dung, are stacked to make a wall that protects the animals from the wind chills, and keep them warm enough to withstand the harsh conditions. These blocks can also be burnt as fuel during the winter. These methods are still practiced today in the westernmost parts of Mongolia, and areas formerly part of the Zuun Gar nation. Because of the semi-permanent structure of the winter shelter for their livestock and the cold, mostif not allnomads engage in transhumance (seasonal migration). They have winter locations to spend the winter, which are in a valley protected by mountains on most sides from the wind, while in the summer they move to more open space. Extent and history It is not uncommon for zuds to kill over one million head of livestock in a given winter. The 1944 record of almost seven million head of livestock lost was surpassed in the 21st century. The arctic oscillation in both 1944–45 and in 2010 was pushed much deeper into Central Asia, bringing prolonged extreme cold weather. In 1999–2000, 2000–2001, and 2001–2002, Mongolia was hit by three zuds in a row, in which a combined number of 11 million animals were lost. During the winter of 2009–2010, 80% of the country's territory was covered with a snow blanket of 200–600mm (7-24 inches). In the Uvs aimag, extreme cold (night temperature of −48 °C / −54 °F) remained for almost 50 days. 9,000 families lost their entire herds while a further 33,000 suffered 50% loss. The Ministry of Food, Agriculture and Light Industry reported 2,127,393 head of livestock were lost as of 9 February 2010 (188,270 horse, cattle, camel and 1,939,123 goat and sheep). The agriculture ministry predicted that livestock losses might reach four million before the end