Corridors for Coexistence

Livestock depredation by carnivores is a globally pervasive and detrimental interaction that leads to economic loss and retaliatory killings. Livestock trailed annually on US Rangelands impact wildlife communities- competing with ungulate herbivores for forage, disrupting predator-prey dynamics, and shifting community structures. In order to promote coexistence in these human-wildlife systems, a better understanding of how these processes interact is needed. However, studies on the topic fail to fully capture both the spatial and temporal signals of moving livestock herds. In this study I investigated the effects of sheep grazing on a wildlife community in the Big Wood River Valley, Idaho. I developed a grazing covariate that was temporally informed; and used a scaffolded modeling technique of single- and multi-species occupancy models to evaluate the effects of grazing and environmental factors on spatiotemporal processes of wildlife. Using an array of remote-triggered cameras, I sampled wildlife occurrence of focal carnivores including gray wolves (Canis lupus), American black bear (Ursus americanus), coyote (Canis latrans), and mountain lions (Puma concolor), along with ungulate herbivores mule deer (Odocoileus hemonius), elk (Cervus canadensis), and moose (Alces americanus). I evaluated processes of detection and occupancy using a single-species model for each species, two 2-species models including wolves and elk and wolves and coyotes, and a 5-species community model including bears, coyotes, mule deer, elk, and wolves. I found that the detection of bears, wolves, and mule deer was positively related in activity to grazing and 16-day NDVI (changing greenness), while the detection of elk was negatively related to grazing and 16-day NDVI. These results suggest a divergence in community makeup as sheep move into an area- increasing predator activity and shifting prey community structure. Furthermore, this work shows that including a temporally informed grazing covariate into a multi-species modeling structure can effectively predict changes in wildlife community activity when livestock are present. These findings have important insights for livestock and wildlife management as the livestock-carnivore human-wildlife system grows more prevalent and pertinent.