and British Columbia. Although a few of the birds were observed in the spring and summer of 1969 the effort to establish a population in Oregon was ultimately unsuccessful. Diet This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring season, while willow catkins, mountain avens flowers, and chickweed blooms, other flowers and leaves, lichens and berries form the majority of the ptarmigan's diet in the summer. Once fall and winter arrive in the region, the ptarmigan feeds on pine needles, seeds, willow and alder buds and twigs. Winter food sources have a much higher cellulose content than does summer forage, so the ptarmigan relies on bacteria-aided digestion in the cecum to extract essential nutrients. During the summer, the ptarmigan eats grit to assist in digesting plant material. Breeding White-tailed ptarmigan males are usually monogamous and remain with the same mate for one breeding season. To attract females, a male will strut and display his tail feathers. The female builds a simple scrape nest on the ground, while the male acts as a sentry to guard the area. The nest is a shallow depression in a snow-free area, generally protected from the wind and is softened with grasses and a few feathers. One side of the nest generally provides a quick escape route. A clutch consists of two to eight eggs, which retain a cinnamon color for most of the incubation period, but develop brown spots when they are nearly ready to hatch. Males remain in the vicinity of the nest until the eggs hatch, a period of about 23 days. The precocial young leave the nest six to twelve hours after hatching. They are at first covered with down but become fully fledged in seven to ten days. Ptarmigan chicks begin their lives eating insects. Once the chicks' digestive tracts and ceca are more fully developed, their diets shift to one of flowers and leaves. Hens choose foraging patches where plant species containing proteins are abundant. The hens call their chicks to these plants, which are critical for the growth and development of the chicks. This suggests that the hens' food calls assist in enhancing survival rates of juvenile ptarmigans. The young birds remain with their mother throughout the summer and autumn season. Adaptations and status The white-tailed ptarmigan is well-camouflaged when on the ground. In his pioneering 1909 book on the subject, Concealing-Coloration