Insects also provide vital nutrients. Unlike other galliforms, sage grouse lack a functioning gizzard, so cannot digest hard seeds. They must eat soft vegetation, like sagebrush leaves and forbs. Hens lay five to seven eggs, which incubate for two to three weeks. Chicks fly soon after hatching, but stay with their mothers and siblings for ten to twelve weeks.
Hens do all the care and feeding.
Males shun domestic duties and do not form lasting pairs. While not faithful to their mates, sage grouse are loyal to their leks, some birds returning to the same site for decades. Sage grouse also seem to have a strong allegiance to places where they feed and nest. Used only for courtship, leks range in size from one to 40 acres or so. On the lek males assert themselves physically and acoustically within a particular territory.