Sage Thrasher

The sage thrasher is considered a sage obligate, and is generally dependent on large patches and expanses of sagebrush steppe for successful breeding. It primarily inhabits areas dominated by big sagebrush (Artemisia tridentate), but has been noted in black greasewood (Sarcobatus vermiculatus) habitat in areas in Utah and Nevada, and bitterbrush (Pursia tridentate) habitat in Washington. Within its range it is more abundant in areas with high sagebrush cover, tall shrubs, woody cover, and bare ground and less abundant in areas with higher percent cover of grasses. In Washington, occurrence was greater on loamy and shallow soils than on sandy soils. Besides the impacts of habitat loss, little is known about factors regulating sage thrasher numbers throughout their range. Temperature and insolation appear to affect nest site selection. Nests are oriented with more easterly exposures than westerly ones, and nest placement patterns are generally consistent with the hypothesis that nests are placed so as to guard against heat loss at night, to avoid direct exposure to the sun during the heat of the day, and to gain heat early in the morning. Temperature and precipitation likely have a greater effect on the distribution of the sage thrasher’s habitat. Sagebrush grows in areas with cold winters and summer drought. Recruitment of subspecies of big sagebrush is dependent upon precipitation amounts during specific time periods, depending on the subspecies.