Ptarmigan is a bronze sculpture of a rock ptarmigan in its winter plumage, standing on the summit of a frost-shattered rock. The bird is shown upright and near life-size, its weight carried on one foot set on the apex of the stone, the head turned to one side and slightly down as it looks out over the ground below. The body is modelled in full, rounded forms, the breast curving down to the folded wings and a long tail that runs back and tapers to a point. A patch of red sits above the eye, the short beak and the eye are dark, and the tail feathers and claws are darker than the pale body. The rock beneath is cut in angular, faceted planes, with two smaller shards rising from the circular base at its foot.

The rock ptarmigan is a member of the grouse family and a close relative of the willow grouse. A bird of higher altitudes, it turns white in winter as camouflage among the snow and ice of the high mountains, which is the state the sculpture takes. Nick Bibby modelled the original in a wax-based clay, from which the bronze was produced by the lost-wax process, moulded, cast in hollow wax, invested and then cast into bronze. He conceived the ptarmigan as a companion to his earlier life-size Gyrfalcon, a bird that shares the same high, rocky, snow-covered ground.