Spatial organization and habitat use of feral cats (Felis catus L.) in Mediterranean California

We report on a preliminary study of the spatial organization, habitat use, and diet of feral cats (Felis catus) in a riparian reserve in central Calif ornia, to assess potential impacts of this exotic predator on native specie s. Home ranges of adult cats averaged 31.7 ha and did not differ significan tly by sex or season. Home ranges also showed little overlap, suggesting a territorial social system. Cats strongly preferred riparian habitats and fo raged primarily on native species of small mammals, especially California v oles (Microtus californicus) and Botta's pocket gophers (Thomomys bottae), although birds, insects, and exotic rodents were also eaten. The preference for riparian habitats and native prey suggests that impacts on biodiversit y by feral cats may be great, especially in Mediterranean climates where ri parian communities already are heavily impacted by urbanization and agricul ture.