Kate McGinn; University of Wisconsin-Madison;; M. Zachariah Peery, John J. Keane, Benjamin Zuckerberg, William Berigan, Ceeanna Zulla, Zach Wilkinson, Josh Barry

While large scale, extreme temperature events associated with anthropogenic climatic change threaten global biodiversity, smaller areas of habitat within a landscape may retain suitable conditions where individuals can seek refuge. The spotted owl is a climate-sensitive, older-forest specialist that is less heat tolerant than other birds, with relatively low upper critical temperatures and limited ability to dissipate heat. We have yet to understand how access to cooler microclimates influences spotted owls during heat waves. In the summers of 2019-2021, we used GPS-tagging, doubly-labeled water injections, and demographic modeling to 1) examine how habitat and elevation interact to influence the temperatures spotted owls experience and 2) measure the effect of cumulative heat exposure on physiological rates. We found that elevation, topography, and canopy cover are significant predictors for microclimates. We also found that water turnover rates, which confer heat dissipating behaviors, increase with temperature, but overall energetic expenditure is only weakly impacted by temperature. Results suggests that the habitat spotted owls select during the day sufficiently buffers individuals from direct heat stress in current conditions, but extreme thermal events impact individual physiology. We will additionally report on the effect of habitat and temperature extremes on spotted owl occupancy. This study, thus, will identify particular areas and forest types that serve as temperature refugia for spotted owls as the climate continues to warm and help integrate the conservation of this species into forest planning activities.

Spotted Owl Ecological Associations   Student Paper Zoom Presentation