Willow ptarmigan with willow and alder trees, heather moors, tundra and mountain slopes. In the winter, females and sub-adults may move to lower altitudes and seek shelter in valleys or in more densely vegetated areas, but adult males usually remain in the subalpine region. The red grouse is common on heather-clad moorland across the north and west of Great Britain and in localised areas of Ireland. The willow ptarmigan has a varied and seasonal diet. The bird is herbivorous for most of its life and subsists on various plant materials. As juveniles, they may feed on insects due to an inability to
White-tailed ptarmigan 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