Frequent, heterogenous fire supports a forest owl assemblage

Fire shapes biodiversity in many forested ecosystems, but historical management practices and anthropogenic climate change have led to larger, more severe fires that threaten many animal species where such disturbances do not occur naturally. As predators, owls can play important ecological roles in biological communities, but how changing fire regimes affect individual species and species assemblages is largely unknown. Here, we examined the impact of fire severity, history, and configuration over the past 35 years on an assemblage of six forest owl species in the Sierra Nevada, California, using ecosystem-scale passive acoustic monitoring. While the negative impacts of fire on this assemblage appeared to be ephemeral (1–4 years in duration), spotted owls avoided sites burned at high-severity for up to two decades after a fire. Low- to moderate-severity fire benefited small cavity-nesting species and great horned owls. Most forest owl species in this study appeared adapted to fire within the region's natural range of variation, characterized by higher proportions of low- to moderate-severity fire and relatively less high-severity fire. While some species in this assemblage may be more resilient to severe wildfire than others, novel “megafires” that are larger, more frequent, and contiguously severe may limit the distribution of this assemblage by reducing the prevalence of low- to moderate-severity fire and eliminating habitat for a closed-canopy species for multiple decades. Management strategies that restore historical low- to moderate-severity fire with small patches of high-severity fire and promote a mosaic of forest conditions will likely facilitate the conservation of this assemblage of forest predators.