FOREST OWLS RESPOND TO HISTORICAL AND NOVEL FIRE DISTURBANCE IN THE SIERRA NEVADA

Kate McGinn; University of Wisconsin-Madison; mcginn4@wisc.edu; Benjamin Zuckerberg, Joshua M. Barry, Gavin M. Jones, Stefan Kahl, Kevin G. Kelly, Holger Klinck, Sheila Whitmore, Connor M. Wood, M. Zachariah Peery

Fire disturbance is a driving force for biodiversity in forested ecosystems, but a new era of megafires that result from land use legacies and climate change has led to prolonged negative consequences for forest specialists. The forest owl community in the Sierra Nevada is presumably adapted to shorter-interval fires of low-moderate severity, but we have yet to quantify how individual species in this guild of avian predators respond to disturbance over space or time. In this study, we leveraged automated detections from passive acoustic surveys in the Sierra Nevada and occupancy models to 1) examine species-specific associations with burned habitat and fire legacies and 2) quantify the effect of novel fire disturbance on forest owl populations. We found that fire disturbance had variable effects of forest owl species, depending on both severity and time. Generally, low severity fire had delayed but posive effect on site occupancy for forest owl species, but high-severity fire generally had an immediate and delayed negative effect on occupancy for most species. Great orned owls were the expection, and they showed a delayed, postive relationship with areas burned at higher severity. Thus, we found evidence that species may benefit from fires that reflect the natural disturbance regime of the region, but fires characteristic of nodel megafires pose concern for forest obligates. More frequent and extreme forest fires may threaten the biodiverstiy of this guild of forest predators, and it is imperative to understand spatial and temporal responses of different species to disturbance to document potentially novel communities in a post-megafire landscape.

Birds I: Owls   Student Paper InPerson Presentation