Environmental disturbances influence the distribution of species across space and time, with important implications for community structure and patterns of biodiversity. For example, both abiotic and biotic short-term disturbances flush concealed prey, providing important food resources to attending species. Disturbance foraging is widespread across diverse animal taxa, yet we currently lack a systematic understanding of how the behavior varies ecologically, geographically, and taxonomically on a global scale. Here, we conducted a systematic literature review of disturbance foraging behavior among birds. We documented disturbance foraging in at least 375 (~4%) species representing 29% (73) of all avian families and 56% (23) of all avian orders. The primary sources of disturbance were biotic, namely terrestrial mammals (~40%) and arthropods (~40%), followed by birds (~11%) and aquatic mammals (~6%). The behavior was most common in forest bird species (? 50% of all observations), followed by savanna/grassland species (~16%) and marine/coastal species (~11%). Geographically, the behavior was much more prevalent in tropical regions, with more than 90% of all observations occurring in the Neotropics (~50% of all observations) and the Afrotropics (~40%). Our findings represent the first global synthesis of disturbance foraging in birds and confirm its prevalence across the avian tree of life.

Portions of the San Francisco Bay Area burned in the summer of 2020. To understand how wildlife communities were affected by the wildfires, we monitored burned and unburned sites using acoustic sensors and cameras. Forty paired sensors, audiomoths and camera traps, were set at 0.5 km intervals in East Bay Regional Parks and Contra Costa Water District Los Vaqueros Reservoir beginning in October 2020. Our goal was to compare diversity (species richness), detection rates (intensity of use), and occupancy estimation (abundance) between the burned and unburned sites and latency to recovery using the unburned area as a comparison. We used a cloud-based acoustic processing pipeline to run an opensource bird call detection model (BirdNET). Wildlife Insights, camera trap data management and image recognition software, was used to process camera data. Image recognition output was confirmed by trained observers. Both audio and image data were used to derive effort, detection rates and single season occupancy estimates using a R-Markdown script developed for the Marin Wildlife Picture Index Project. We have tools and approaches that can be easily replicated; these protocols and R-Markdown scripts are available for use and are based on internationally accepted metrics for measuring trends in biodiversity. Understanding diversity, intensity of use and abundance as well as documenting rare species all provide the most basic, but very important information about the health of our ecosystems, and perhaps more importantly, how they may be changing.

Megafires are increasingly common in Sierra Nevada forests, yet their impact on wildlife has been systematically studied for relatively few species. Both biodiversity conservation and ecosystem restoration will benefit from an expanded understanding of the implications of such disturbances for ecological communities. In fall 2020, the North Complex Fire burned 129,000 ha in the Plumas National Forest, almost all of which lay within a long-term, landscape-scale passive acoustic monitoring program. This enabled us to conduct a Before-After Control-Impact study design to test for changes to avian species richness and composition resulting from the fire. We are combining systematic passive acoustic survey data recorded in May – June 2020 and 2021, the BirdNET algorithm, which can identify >95% of Sierra Nevada birds by sound, and a dynamic occupancy model that accounts for false positives and detection counts. Individually, these components are novel tools in applied ecology; together, we expect them to yield unprecedented insights into community-level population responses to emerging disturbance regimes. These results, which will entail 60-120 species depending on classification accuracy, will be relevant across the Sierra Nevada – particularly because acoustic survey coverage now extends across the entire region.

The Sierra Nevada yellow-legged frog inhabits both alpine lakes and high elevation mountain streams. At the northern extent of their range, streams become more commonly utilized as both breeding and non-breeding sites. One intensively monitoring and managed population at the northern extent of the species range was subjected to an intense crown-replacing wildfire in July 2021. The Bean Creek Sierra Nevada yellow-legged frog population contained approximately 66 individual adult frogs when the entire population extent was burned in California’s Dixie Fire. There were 55 frogs found in 2021 prior to the fire. 47 were found in 2021 after the fire. The population was subjected to two main fire types, intense crown-replacing high severity fire and low to moderate fire behavior with group torching and understory burning. This presentation will compare population level changes in the different fire severity types. Zoo-reared frog survivorship will be compared to wild frog survivorship. This species has proven to be resilient to high severity fire in small stream systems with intermittent channels and perennial pools. The presence of deeper pools (0.5 – 1 meter deep) appeared to provide refuge habitat.

Climate change and fire suppression are leading to an increased prevalence of ‘mega-disturbances’ such as drought and wildfire in terrestrial ecosystems. We studied the occurrence dynamics of an iconic old-forest species, the spotted owl (Strix occidentalis), on a long-term study area in the Sierra Nevada, CA, USA from 1989 to 2020 to evaluate their multi-scale population response following a 2014 megafire (the ‘King’ Fire) that affected a portion of our study area. We found that extensive severe fire within spotted owl sites resulted in both immediate site abandonment and prolonged lack of re-colonization by owls six years post-fire. Sites that experienced high pyrodiversity – a mosaic of burn severities – were more likely to persist after the fire, but this effect was only apparent at finer spatial scales. A potentially confounding factor, post-fire salvage logging, did not explain variability in the probability of either owls persisting at sites or sites becoming re-colonized; effects could be attributed only to severe fire extent and pyrodiversity. Our study demonstrates the prolonged effects of severe fire on the occupancy of this forest-dependent species, suggesting that forest restoration that reduces megafires could benefit spotted owls.