NATURAL HISTORY

MONO BASIN AREA GREATER SAGE GROUSE } Centrocercus urophaianus
FAMILY: Phasianidae

DESCRIPTION: The largest grouse in North America, the greater sage grouse is a chicken-like bird reaching lengths of up to 30 inches, heights of up to two feet, and weights of four to seven pounds. Males are larger than females and have a white breast, a black throat and belly, a yellow comb, and yellow air sacs that are inflated during mating displays. Females have grayish brown plumage and a buff-colored throat with black markings.

HABITAT: Sage grouse require sagebrush varieties throughout the year for food and cover; seasonal habitats consist of sagebrush, grasses, and forbs.

RANGE: The Mono Basin area sage grouse exists in six population management segments and ranges from Storey County, Nevada to Inyo County, California.

MIGRATION: Sage grouse stay in the same general region year-round but range widely between leks, brood-rearing areas, wet meadows and riparian zones, loafing and feeding areas, and winter habitat. In general, summer habitat consists of sagebrush stands and forb-rich wet meadows and riparian areas, while winter habitat is located in lower-elevation sagebrush-dominated landscapes that continue to provide green forbs.

BREEDING: Sage grouse breeding activities occur from March to early June. Males congregate at mating sites, or “leks,” to compete for mates. Immediately after mating, Mono Basin hens leave the lek and lay an average of six to seven eggs in shallow nests, incubating them for approximately 25 to 29 days. If the first nest is lost to predation or severe weather, hens will sometimes re-nest, but second clutch sizes are often smaller.

LIFE CYCLE: Greater sage grouse generally live from 1 to 1.5 years, but some have been known to live up to 10 years in the wild.

FEEDING: Greater sage grouse primarily eat green plant matter, but will also consume flowers, insects, and sometimes seeds. Grasshoppers, beetles, and ants are an important food source for very young birds.

THREATS: The biggest threat to the Mono Basin sage grouse is habitat loss and fragmentation from development, livestock grazing, off-road vehicle use, and increased fire frequency and intensity. The bird is also in danger from drought and the spread of invasive plants.

POPULATION TREND: Overall, the greater sage grouse’s range and distribution have been reduced by 56 percent, and populations have declined by as much as 93 percent from presumed historic levels. The Mono Basin sage grouse has suffered an even greater reduction in range than sage grouse across the West, with current populations having declined significantly from historic estimates. Habitat in the California portion of the grouse’s range has been reduced by more than 70 percent and continues to shrink.

Greater sage grouse photo by Dave Menke, USFWS