Sydney Stephens, University of Trento

Low-elevation shrublands of the red rock deserts in southeastern Utah have traditionally been treated as marginal, transitory habitat for forest-associated large mammals between “sky island” mountain ranges. However, increasing observations of black bears (Ursus americanus) and other large mammals near Castle Valley suggest that desert habitat use may be more frequent, prolonged, and climatically mediated than previously assumed. We are developing a long-term camera-trap monitoring network to test the hypothesis that poor winters—indexed by reduced snowpack, altered freeze timing, and drought-linked declines in landscape productivity—increase movement and desert corridor use by black bears dispersing from the La Sal Mountains toward the Book Cliffs region of southeastern Utah. Using a two-tier sampling design, we will deploy permanent “sentinel” cameras in hypothesized desert corridors (canyons/washes and travel choke points) paired with rotating “pulse” arrays at mountain edges and desert control areas.

This design is motivated by preliminary camera-trap detections and stable isotope evidence consistent with prolonged low-elevation use: hydrogen isotope values (δ²H) differed significantly between desert (Rio Mesa/Castle Valley) and the La Sal source area (p = 0.03) and did not vary by month, suggesting at least some individuals may rely primarily on low-elevation resources rather than using them only as brief dispersal routes.

Primary outputs include changes in probability of corridor use, identification of high-function corridors, and multi-species co-occurrence patterns to test whether corridor selection shifts with predator–competitor presence. This scalable, non-invasive framework will quantify climate-linked pulses of corridor use and community change in arid landscapes, supporting proactive corridor prioritization and conflict-prevention as winters become increasingly variable and outdoor tourism in this region increases.