Impacts of large-scale restoration efforts on black bear habitat use in Canyon de Chelly National Monument, Arizona, United States

Impacts of large-scale changes in habitat due to human development, invasive species, and climate change are important considerations for wildlife management. Likewise, as efforts increase to recover and restore human-altered landscapes, indirect consequences on nontarget components of the restored ecosystem also must be considered. Currently, efforts are underway to eradicate nonnative Russian olive (Elaeagnus angustifolia) and tamarisk (Tamarix spp.) in Canyon de Chelly National Monument (CACH), United States, yet impacts to native wildlife, including the American black bear (Ursus americanus), which relies on these species for escape cover and foraging habitat, are not fully understood. Further, these efforts have the potential to impact sociopolitical aspects of the ecosystem, namely human–bear interactions (e.g., raiding of crops and livestock). We used occupancy modeling to evaluate black bear foraging ecology and habitat use in CACH to better understand how bears are using native and nonnative habitat resources and how restoration efforts may impact bears and human–bear interactions. We found that black bears rely heavily on Russian olive for food and that habitat use is driven by both native and nonnative (i.e., Russian olive) food resources; thus, restoration of native habitat in CACH may have negative impacts on bears through loss of a primary nonnative food source and escape cover. Furthermore, bear–human interactions may temporarily increase in the short term as bears adjust to this loss. Evaluating habitat use in an occupancy modeling framework provides an effective means for gauging nontarget impacts of restoration efforts on wildlife species, an essential step in effective wildlife management.