California State University, Long Beach, United States
Abstract: Wildfires have historically been a part of California ecosystems, playing a key role in shaping vegetated landscapes. However, anthropogenic disturbances such as urbanization and climate change are altering fire regimes in the 21st century, posing a growing threat to native flora and fauna. While the effects of wildfire on plant and small mammal communities have been well-studied, little research has been conducted the post-fire succession of mesocarnivore species. Our project goals are to conduct long-term (7 year) monitoring of mammal occupancy in recently burned areas of Santa Cruz and Orange County, California, and to determine how occupancy is related to environmental covariates and species-specific life history traits. We collected pre- and post-fire detection data at burned and unburned sites in areas affected by the Canyon 2 (2017), Silverado and Bond (2020) fires in Orange County, and the CZU Lightning Complex (2020) in the Santa Cruz mountains. To explain variation in site occupancy and recolonization rate, site-level environmental covariates were generated from Landsat 8 OLI raster data and each species was given a score for habitat and dietary flexibility and mobility based on current literature. We fit single species autologistic occupancy models to compare occupancy of burned and unburned areas over time. Preliminary results suggest that generalist species (e.g., coyotes) do not display strong preference for burned or unburned sites, while dense vegetation specialists (e.g., bobcats) displayed an avoidance of recently burned sites. The interspecific variability in post-fire site selection suggests that generalist and disturbance-tolerant species may be more capable of exploiting post-fire resources at early successional stages, creating “winners” and “losers” under shifted fire regimes. Our future directions are to explore post-fire succession of other commonly detected California mammal species (e.g., mountain lions) and determine how mammal occupancy at burned and unburned sites is related to environmental covariates.
