Conservation decision-making for threatened species in human-modified landscapes requires detailed knowledge about spatial ecology, but robust data derived from tracking individual animals are often unavailable, with management decisions potentially based on unreliable anecdotal data. Existing data are limited for Hispaniola's two threatened non-volant land mammals, the Hispaniolan hutia (Plagiodontia aedium) and Hispaniolan solenodon (Solenodon paradoxus), with assumptions that hutias are better able to tolerate landscape disturbance. We collected spatial behaviour and habitat use data for Hispaniolan mammals during a multi-year field programme across undisturbed and modified habitats in southwestern Dominican Republic, using GPS units for hutias (11 individuals) and radio-telemetry for solenodons (22 individuals). Although significant differences exist in hutia home range estimates between different GPS error derivation strategies and estimated terrestrial/arboreal behaviour scenarios (95% KDE means = 23,582–28,612 m2), hutias almost exclusively use forest under all estimates (mean observations in forest across all strategies/scenarios = 90.3%, total range = 69.1–100%). Solenodons have larger estimated home ranges (95% KDE mean = 156,700 m2), with differences between wet and dry season estimates, and show much more variation in habitat use than hutias within the same landscape; animals regularly use both forested and modified habitats, being observed most frequently in forest (mean = 74.0%, range = 13.0–99.1%) but also occurring regularly in pasture (mean = 15.9%, range = 0–80.0%) and cropland (mean = 7.7%, range = 0–62.0%), and den in all three habitats. This new baseline on Hispaniolan mammal spatial ecology challenges anecdotal data, and suggests solenodons may be better able to tolerate disturbance and persist in modified landscapes.