Spatial segregation mediates interactions between large and mesocarnivores in the Chihuahuan Desert

The coexistence of carnivores often requires niche partitioning—a division of resources that shapes ecosystem dynamics and has important consequences for community composition and biodiversity. Niche partitioning may be especially important in the Chihuahuan Desert where resources are limited, and environmental conditions are harsh. Despite extreme temperatures and low productivity associated with arid climates, the Chihuahuan Desert harbors a high diversity of meso and large carnivores, including the Cougar (Puma concolor), Coyote (Canis latrans), Bobcat (Lynx rufus), and Gray fox (Urocyon cinereoargenteus). In desert ecosystems, mammals often rely on survival strategies like estivation, nocturnality, and crepuscular activity to avoid extreme heat that can constrain their ability to segregate along the temporal axis. We hypothesized strong spatial and trophic partitioning but limited temporal segregation due to extreme thermal constraints. To assess niche partitioning, we examined spatial, temporal, and trophic segregation using camera traps to record carnivore occurrence and prey abundance. We analyzed the influence of landscape variables (elevation, habitat integrity, distance to water, distance to Protected Areas, distance to closest town, distance to highways, and vegetation type area) on carnivore occurrence and explored patterns of diel activity across seasons. By integrating carnivore occurrence data with prey activity, we identified key drivers of coexistence in this extreme environment. Our results indicate that carnivores in the Chihuahuan Desert primarily rely on spatial segregation to reduce competition, while showing high temporal overlap with both conspecifics and prey. The lack of strong temporal or trophic segregation suggests that additional factors, such as human disturbance and differences in body size, may play a crucial role in shaping niche partitioning in this extreme ecosystem.