The cock spruce grouse begins his courtship display during the first warm days of April. He struts pompously in a tree or on glistening snow with bright red eye combs erect, stiffened wings dropped at his sides, tail elevated and fanned, and neck and upper breast feathers ruffed. In May, he also begins to perform peculiar aerial displays by flying steeply downward from a tree and settling to the ground on rapidly beating wings, producing a muffled drumming audible for 100 to 200 yards. During May, the hen lays 5 to 9 eggs in a shallow nest lined with twigs, leaves and a few feathers. The nest is usually at the base of a spruce tree but is sometimes beneath a log.
Insects are an important food for newly hatched chicks.
In late August, they begin frequenting stream sides, lakeshores and roads in early morning to secure grit for the coming winter months. The sharp, hard particles of rock are apparently essential for grinding the fibrous spruce needles that are the sole source of nourishment in winter. During the short winter days, the birds rest and feed in spruce trees. Recently, they have been introduced into the Matanuska and Susitna river valleys in Southcentral Alaska where they are flourishing. In summer and fall, these birds are often found in alder thickets and willow bottoms, as well as in spruce-birch forests and aspen groves.