Interactions between feral dogs and dwarf peccaries on Cozumel Island: insights into occupation and density

Feral dogs (Canis lupus familiaris) are invasive predators derived from domestic dogs that have established wild populations that pose serious threats to native island fauna. On Cozumel Island, Mexico, we assessed the spatial ecology of feral dogs and their potential effects on the dwarf peccary (Dicotyles tajacu nanus), a native and ecologically important subspecies. Using 7,558 camera trap days and trail surveys, we applied occupancy and co-occurrence models to evaluate habitat use and species interactions. Feral dog occupancy was estimated at Ψ = 0.35 ± 0.09, with a density of 1.47 ± 0.6 individuals/km2. Dog presence was associated with proximity to freshwater sources and vegetative cover. Dwarf peccaries were detected more frequently in semi-deciduous forests and in areas farther from human settlements. Spatial overlap between the species was high (γ = 0.91), and peccary detection rates were significantly reduced at stations where dogs were present. Post hoc analyses suggest that both species select similar environmental features but may differ in spatial use due to risk sensitivity. These findings underscore the potential for indirect impacts of invasive predators on native species' habitat use. We recommend integrated management combining population control, public awareness, and habitat protection to mitigate the ecological impact of feral dogs on Cozumel's native fauna.