Patch characteristics and domestic dogs differentially affect carnivore space use in fragmented landscapes in Southern Chile

Abstract

In an increasingly anthropogenic world, native species face multiple interacting threats. Habitat fragmentation and domestic dogs are two such perturbations threatening terrestrial mammals globally. Here, we implemented a camera trap survey in the fragmented central valley/Andean foothills transition of the Los Lagos Region in Southern Chile to evaluate space use of native carnivores in a landscape comprised of patches of native forest amidst a matrix of pastureland. Using an occupancy modeling framework to account for imperfect detection, we examined the impacts of dogs and landscape metrics of fragmentation on three mesocarnivores - the foxes culpeo (Lycalopex culpaeus) and chilla (Lycalopex griseus) and the wild cat guina (Leopardus guigna). Factors driving occupancy differed for each of the native species, while detection rates for both canid species increased with dog occupancy. We found that a small (12%) simulated increase in dog occupancy negatively impacted the spatial use of the culpeo. Habitat loss and fragmentation were positive drivers for the chilla and the dog, and indirectly impacted the culpeo through the domestic dog. The guina did not respond to fragmentation and other habitat covariates or dog occupancy. Instead, all native carnivore species temporally partitioned diel activity with dogs. We highlight that the effects of dogs or fragmentation are not ubiquitous across the carnivore guild with varied tolerance. However, future conditions of increased fragmentation and habitat loss will likely increase the potential contact between domestic dogs and native carnivores.