Spatio‐Temporal Mechanisms of Coexistence Between Two Generalist Mesocarnivores, the Red Fox and the Stone Marten

ABSTRACT The study of mechanisms underlying coexistence among animals is essential to understand species' roles in ecosystems. Spatial and temporal segregation can facilitate mesocarnivore coexistence under interspecific competition. We investigated activity and occupancy patterns of two abundant mesocarnivores in the central Iberian Peninsula, the red fox ( Vulpes vulpes ) and the stone marten ( Martes foina ), along with their main prey: small rodents and the European rabbit ( Oryctolagus cuniculus ). Camera‐trap surveys were conducted across 24 sampling locations, encompassing heterogeneous Mediterranean landscapes during cold and warm seasons. Using multispecies occupancy models and circular activity distributions, we evaluated coexistence between both mesocarnivores. We evaluated relative abundance of mesocarnivores and prey as a key factor modulating co‐occurrence and interactions between foxes and martens. Results revealed high spatial co‐occurrence ( ψ [11] = 0.604), with stone marten conditional occupancy increasing more than two‐fold in sites occupied by red foxes ( ψ = 0.749) compared to fox‐absent sites ( ψ = 0.290). This positive spatial interaction was strongly driven by relative abundance (ʄ12 = 1.991). Conversely, temporal overlap between foxes and martens was low to moderate ( Δ = 0.744–0.807), with greater divergence in activity patterns when both were abundant. Marten–rodent temporal overlap remained consistently high ( Δ = 0.842–0.936) but decreased ( Δ = 0.779) when fox–rodent activity synchronized. These findings demonstrate that spatial aggregation is shared by red foxes and stone martens in Mediterranean ecosystems lacking top‐down forces from apex predators. Under this scenario, fine‐scale temporal segregation serves as the primary mechanism maintaining stone marten coexistence by mitigating intraguild risk within the landscape of fear.