COMPANION ANIMALS SYMPOSIUM: Sustainable Ecosystems: Domestic cats and their effect on wildlife populations.

Abstract

Domestic cats are estimated to kill billions of small mammals and birds each year. In certain areas of the world, it is not uncommon for either feral or free-ranging cats to have high population densities, creating concern regarding their level of hunting. Many cats are considered to be subsidized predators, as they receive care and food from humans. Arguments abound regarding the presence of cats in the habitats of native small mammals and birds and whether or not local ecosystems can sustain this predator-prey relationship. The effects of cats on native wildlife can depend on several factors, including cat classification (feral vs. free ranging vs. indoor-outdoor), geographical location (islands vs. mainland), and type of habitat (rural vs. suburban vs. urban). Feral and free-ranging cats may have a greater impact on native species on islands because habitat is severely limited. Continued urbanization and development of rural areas also creates fragmented habitats, and native species may struggle to survive with the added pressure of hunting by domestic cats. Additionally, cats in rural areas are frequently fed by humans, which can support high population densities and intensify pressure on native species. Species targeted by cats may also vary based on prey availability in different areas, but small mammals are generally preferred over birds, reptiles, or invertebrates. Domestic cats certainly have the potential to roam and hunt in very large areas inhabited by native species and loss of biodiversity is a major concern. Therefore, it is possible that ecosystems may not be able to sustain hunting by domestic cats. Because this predator-prey relationship is probably not sustainable, it is necessary to responsibly manage outdoor domestic cats.