Habitat Relationships and Breeding Passerine Birds on the Snake River Birds ofPrey Area

摘要

The study team surveyed breeding passerine abundance throughout the Snake RiverBirds of Prey National Conservation Area at 145 sites previously sampled in 1991-1993. Analysis for habitat associations of species was similar to results for previous years. Shrub-obligate species were associated with big sagebrush (Artemisia tridentata) or saltshrub habitats and disturbance, and grassland species, such as horned larks (Eremophilia alpestris) and western meadowlarks (Sturnella neglecta) were clustered in disturbance habitats. The team monitored outcomes for nests of Brewer's sparrows (Spizella breweri) and sage thrashers (oreoscoptes montanus). Brewer's sparrows were successful in fledging young at 11 or 15 nests, and sage thrashers were successful at only 4 of 13 nests. Nesting success was not associated with any local vegetation or landscape characteristics that were measured.