Within the sagebrush steppe ecosystem in the intermountain west, sagebrush obligate birds occupy a variety of specialized niches. The purpose of our research was to identify the effect of road presence and habitat covariates on the density of sagebrush obligate birds during their breeding season. Roads through sagebrush threaten local bird abundance through anthropogenic disturbance and habitat fragmentation (Knick et al. 2012). However, research in the sagebrush steppe has historically focused on Sage-grouse; in our study area specifically, Gunnison Sage-grouse (Centrocerus minimus) (Young et al. 2020). Sagebrush obligate and near-obligate songbirds include the Brewer’s sparrow (Spizella breweri), sage thrasher (Oreoscoptes montanus), green-tailed towhee (Pipilo chlorusus), and vesper sparrow (Pooecetes gramineus). We assessed avian density in response to road presence and four habitat covariates at an approximate individual bird territory scale (3.14 ha or the area of a 100 m buffer around a survey point). We found that the effect of road presence varied between our study species but overall it was not a significant relationship. Additionally, we found that increased vegetation heights over 2 m were consistently associated with declines in our study species’ densities and that increased shrub cover consistently increases study species densities. These findings indicate the importance of species specific monitoring in relation to habitat fragmentation and territory patch scale habitat conditions in sagebrush steppe ecosystems.
