The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a sagebrush (Artemisia spp.) obligate species and a candidate for listing under the Endangered Species Act of 1973. The Box Elder Sage-Grouse Management Area (SGMA), located in northwestern Utah, encompasses one of the state's largest sage-grouse populations. Other than lek locations, little was previously known about the general ecology of the sage-grouse inhabiting the Raft River subunit of this SGMA. More information was needed regarding the status of this population and the effects of previous management actions. 

From January 2012 through December 2013, I captured, radio-marked, and monitored 123 (68 female, 55 male) sage-grouse in the Raft River subunit. My objectives were to describe the effects of microhabitat use and breeding season foraging patterns on the seasonal movements, survival, and reproductive rates of this sage-grouse population. 

Sage-grouse in the Raft River subunit have distinct winter and summer ranges, with the breeding areas overlapping the winter range. Some individuals travelled long distances between their winter and summer range, while others moved only a few kilometers. Annual survival rates were similar to Utah and range-wide averages, being slightly higher for females than males. Nest and brood success rates were above most Utah and range-wide averages. 

I conducted vegetation surveys at sage-grouse use sites and random sites to determine if specific habitat preferences exist in this population of the species. Sage-grouse in the study area selected sites with specific vegetation characteristics to fit their seasonal needs. Sage-grouse use sites were greater overall in forb height, grass height, and shrub height and cover than random sites. Successful females selected nest sites with greater forb height and cover and grass and shrub height than unsuccessful nesting females. Brooding females selected sites greater in forb, grass, and shrub height than non-brood sites. 

During March and April 2013, I monitored 41 (29 female, 12 male) radio-marked sage-grouse at flock browse sites. The sagebrush plants browsed at these sites did not differ from non-browsed and random plants in nutritional quality and chemical composition. Black sagebrush (A. nova) was lower in percent crude protein and higher in total monoterpene concentration than Wyoming big sagebrush (A. tridentata wyomingensis ). Radio-marked females were frequently found in association with sites where black sagebrush was browsed, and an unidentified monoterpene was considerably more concentrated in browsed plants associated with females that nested successfully.