Montana Field Guide

Sage Grouse is the largest of Montana's grouse. Both sexes have relatively long, pointed tails, feathered legs, and mottled gray-brown, buff, and black plumage. Males have a blackish-brown throat patch and an inconspicuous yellow eye comb. Both sexes have blackish bellies which contrast sharply with white under-wing coverts when the birds are in flight. Females appear to dip from side to side while flying. Adult males range from 26 to 30 inches in length and average 4 to 7 pounds in weight; adult females range from 19 to 23 inches in length and 2.5 to 3.5 pounds in weight (FWP).

A female pheasant can possibly be confused with a female or young Sage Grouse. Female pheasants, however, have a brown belly and bare legs, while female Sage Grouse have a black belly patch and feathered legs (FWP). They differ from Sharp-tailed Grouse (Tympanuchus phasianellus) in having a black belly and in lacking white outer tail feathers.

Sagebrush is the preferred habitat (FWP). They use 6 to 18 inch high sagebrush covered benches in June to July (average 213 acres); move to alfalfa fields (144 acres) or greasewood bottoms (91 acres) when forbs on the benches dry out; and move back to sagebrush (average 128 acres) in late August to early September (Peterson 1969).

Chicks eat mostly insects (60%); juveniles mostly forbs (75%) (dandelion and salsify); adults mostly big sagebrush and dandelion (79%) (Peterson 1969, Martin 1965).

Lek activity extends from March to May. Mating sites move from year to year; nests are located 0.2 to 6.5 miles from the lek (Harrison 1972). Birds were abundant in L38 last century and are now gone (Skaar 1969). Grazing and agricultural development led to a 50% decrease in populations by the 1930s (Mussehl 1971).

In southwest Montana 34% of hens observed had broods, with the average size being 4.3 (Martin 1965). Courtship starts in early March and persists to nesting in May (Davis 1961). Egg records are probably similar to Wyoming: April 18 to July 27 (Johnsgard 1986).