Effects of wildfire on the distribution of mammals and birds in a working shrub‐steppe landscape

The intensity, frequency, and extent of wildfire have increased drastically in the sagebrush ( Artemisia spp.) ecoregion within Washington, USA, over the last few decades. Wildfire on this landscape, already modified and fragmented by agriculture and other disturbances, may challenge the persistence of wildlife that depend on continuous shrublands and grasslands. Therefore, we examined how fire and vegetation characteristics of sagebrush patches influence the distribution of sagebrush‐dependent mammals and birds across the Columbia Basin. Over four summer field seasons (2021–2024), we surveyed 155 burned and unburned sagebrush sites using a combination of camera traps, avian point count surveys, and vegetation surveys. From these data, we assessed how recent (within 20 years of survey) fire and vegetative characteristics affect site use and abundance of wildlife using occupancy models and generalized linear models. We documented 22 avian and mammalian species during camera trap surveys and 77 avian species during point counts. We failed to detect some of the most threatened sagebrush‐dependent species during our surveys, suggesting widespread population loss and limited ranges of this subset of species that are not necessarily due to fire alone. For the remaining species, although we documented many species within burned sites (86 species), we found sagebrush‐obligate passerines and several other species at higher abundances in unburned sites. Within burned patches, fire age, annual grass cover, and forb cover were associated with site use and abundance, and responses to fire and vegetative characteristics varied among taxa and their degree of specialization. Annual grass cover had a largely negative effect on this community, suggesting that invasive Bromus tectorum not only affects the fire regime but also does not support sagebrush‐steppe wildlife. In general, shrub‐dependent species responded positively to increasing vegetative structure and cover. Taken together, our results suggest a need for short‐term postfire management, such as elimination of annual grasses or faster recovery of vertical cover, and a focus on human‐initiated fire prevention. Moreover, our results can inform long‐term planning decisions related to fire resiliency for Columbia Basin mammals and birds.