forbs, grasses, and sedges, often digging through the snow to obtain food in winter. Their natural predators include wolves, lynx, and snow leopards, and red foxes are known to prey on young calves. Tibetan antelope are gregarious, sometimes congregating in herds hundreds strong when moving between summer and winter pastures, although they are more usually found in much smaller groups, with no more than 20 individuals. The females migrate up to yearly to calving grounds in the summer, where they usually give birth to a single calf, and rejoin the males at the wintering grounds in late autumn. Reproduction The rutting season lasts from November to December. Males form harems of up to 12 females, although one to four is more common, and drive off other males primarily by making displays or chasing them with head down, rather than sparring directly with their horns. Courtship and mating are both brief, without most of the behaviour typically seen in other antelope species, although males do commonly skim the thighs of females with a kick of their fore legs. Mothers give birth to a single calf in June or July, after a gestation period of about six months. The calves are precocial, being able to stand within 15 minutes of birth. They are fully grown within 15 months, and reach sexual maturity during their second or third year. Although females may remain with their mothers until they themselves give birth, males leave within 12 months, by which time their horns are beginning to grow. Males determine status by their relative horn length, with the maximum length being achieved at around three and a half years of age. Although the lifespan of Tibetan antelopes is not known with certainty, since so few have been kept in captivity, it is probably around 10 years. Conservation Since 1979, Tibetan antelope has had legal protection under the Convention on International Trade in Endangered Species (CITES). Killing, harming or trading in the animal is illegal worldwide, as more than 160 countries are CITES signatories. It also used to be listed as Endangered by the World Conservation Union and the United States Fish and Wildlife Service due to commercial poaching for their underwool, competition with local domesticated herds, and the development of their rangeland for gold mining. Tibetan antelopes' underfur (down hair), being extremely soft, fine and warm, is known as shahtoosh and has traditionally been woven by