At the Edge (Episode 9) All but invisible, the snow leopard waits. On great cliffs across the valley, bharal males fight viciously over mating rights. They neglect to eat. Many are injured. The snow leopard bides its time until nightfall when it will prey on the weak. December is freezing and bleak in the Rumbak valley of Ladakh, northern India. Five thousand metres up, the air contains only half the oxygen of a breath taken at sea level. On the rain-shadowed northern side of the Himalaya, few plants grow. Much of the landscape is vertical. Higher up the valley a wolf pack violently rejects an application to join by a young lone wolf. He must settle for a wary scavenge of the packs old kill. Little meat is left. Only the bone-eating bearded vulture can extract an adequate meal. The lone wolf moves off, driven to keep trying to join a pack no matter what. As winter days lengthen streams thaw and the amazing dipper bird goes diving for insect larvae under the ice. Bharal climb to higher, flatter country to the first green grazing of the year. The snow leopard climbs with them. A Tibetan wolf tries his luck at hunting the bharal herd but they escape to the cliffs where the wolf lacks the agility to follow. The cliffs are the bharals home; but they also harbour the silent snow leopard. The wolf hunts for a family of nine. He and his partner risk staying in one place for seven weeks while they rear their cute, demanding pups. Wolves are most at risk from poor farmers who grow crops in the valley floor and bring goats to the high pastures in the warmer months. The wolves kill any stray goats and regurgitate the meat for their pups. Outside wildlife protection areas like Rumbak, farmers beat pups to death with sticks. Himalayan marmots have just emerged from hibernation. A golden eagle pairs ancient nest is high in a cliff near the marmot colony. They have two chicks to feed. The colony is their local supermarket. The hunt is spectacular and successful. The chicks thrive. Marmots have no choice but to remain out in the open and at risk - they must pack a years eating into half that time. When bharal infants are born in the brief summer, eagles kill them too. Snow leopard feast on pregnant bharal and defenceless kids. Bharal make the most of a bounty of new grass that grows on the valley floor irrigated by snow melt. Despite the best efforts of their mothers, only half the bharal infants survive their first year. By autumn the herd is cold, some of its members weak with hunger. The snow leopard kills a stumbling female. For three days the snow leopard eats and defends its kill against scavengers. Despite the cats best efforts, a red fox, magpies and choughs manage to feed. By the third day the snow leopard has eaten enough meat to make the carcass light enough to be dragged up the cliffs. The cat goes to extraordinary lengths to save the last of its kill. Every mouthful is precious in this spare place. For a week or so the bharal herd is safe. Then hunger will force the snow leopard to hunt and kill once more.