Also called the rock rabbit, the diminutive pika belongs to the order of hares and rabbits. Resembling a small guinea pig, this sturdy creature spurns hibernation as a way to beat the challenge of winter. Instead, it spends the summer laying in a store of hay for the lean season, spreading cut grass to cure upon the rocks and tending its “haystacks,” on which its survival hangs. Winter is a great peril to small mammals. Their small bodies, because of a large surface area in relation to volume, retain heat poorly, and their high metabolic fires consume calories quickly. Great amounts of energy are required to sustain an active animal in rough terrain, placing further demands on the animal’s capacity to survive the cold. The pika may need to stack as much as 25 kilos of hay; to keep its furnace burning during winter it will have to fuel its stomach almost hourly. Small animals of cold climates often show distinctive body adaptations. On the pika the small, rounded ears lie flat along the head, the tail is inconspicuous, the legs are short; heat loss from exposed surfaces is thus reduced. Fur insulates the soles of the pika’s feet while at the same time providing good traction on steep rock faces. Hidden below these rocks are the hibernating marmots and the sleeping ground squirrels. Beneath the snow the mice, shrews, and pocket gophers struggle on with their lives. But above ground, directly confronting this arctic climate, are the pika, the ptarmigan, and the mountain goat. A triumph of adaptation, the mountain goat faces the winter day without benefit of either the pika’s den or the ptarmigan’s snow roost. The nanny and kid descend from their ledge to search out browse at treeline with other members of a loose band—yearlings, young males, other nannies with kids. At the fringes of the band a solitary adult billy only grudgingly associates with other members of his kind; for this is the season of rut. Not really goats at all, these relatives of the European mountaineering chamois are insulated from the wind by coats of long, hollow-haired fur overlying woolly underfur. They are stocky, stiff-legged, and deliberate, able to negotiate the walls and pinnacles with their superbly adapted hoofs. The unique design of these hoofs gives the animal great traction and stability on precarious crags. Opening towards the front, the cleft between the two hoofs spreads each outward as the animal descends a slope, helping to grip the rocky surface. In addition, the large, rough, and pliant sole of each foot conforms to the bare rock, increasing traction.